- Email: [email protected]
Early Histopathological Changes in New-Onset Diabetes After Kidney Transplantation
Early Histopathological Changes in New-Onset Diabetes After Kidney Transplantation B. Bordaa,*, Y. Munir Ibrahima, C. Lengyelb, T. Várkonyib, A. Kubikc, C. Keresztesd, and G. Lázára a Department of Surgery, Faculty of Medicine, University of Szeged, Szeged, Hungary; bFirst Department of Internal Medicine, Faculty of Medicine, University of Szeged, Szeged, Hungary; cDepartment of Urology, Faculty of Medicine, Semmelweis University, Budapest, Hungary; and dDepartment for Medical Translation and Communication, Faculty of Medicine, University of Szeged, Szeged, Hungary
ABSTRACT Background. New-onset diabetes after transplantation (NODAT) is one of the most common complications after kidney transplantation. Methods. Patients were randomly assigned to receive cyclosporine Aebased or tacrolimusbased immunosuppression. Fasting and oral glucose tolerance tests were performed, and the patients were assigned to one of the following 3 groups, on the basis of the results: normal, impaired fasting glucose/impaired glucose tolerance, or NODAT. NODAT developed in 14% of patients receiving cyclosporine Aebased immunosuppression and in 26% of patients taking tacrolimus (P ¼ .0002). Results. Albumin levels were similar, but uric acid level (P ¼ .002) and the age of the recipient (P ¼ .003) were significantly different between the diabetic and the normal groups. Evaluation of tissue samples revealed that acute cellular rejection and interstitial fibrosis/tubular atrophy were significantly different in the NODAT group. Changes in the Banff score provided significant difference regarding tubulitis and interstitial inflammation (P ¼ .05). Conclusions. The pathological effect of new-onset diabetes after kidney transplantation can be detected in the morphology of the renal allograft earlier, before the development of any sign of functional impairment.
N
EW-ONSET diabetes mellitus after transplantation (NODAT) is one of the most common complications after kidney transplantation. The diagnosis of NODAT is often late or missed; therefore, it impairs the implanted renal allograft. Not only does untreated NODAT negatively influence the allograft, but it increases the risk of cardiovascular diseases (ischemic heart disease, hypertension, and hyperlipidemia) and death [1e4]. NODAT is the same risk factor of cardiovascular diseases as diabetes diagnosed before the transplantation [1]. Its etiopathogenesis is complex; endogenous factors, such as severe obesity, positive family history, age, hepatitis C and cytomegalovirus infection, and immunosuppressive (IS) therapy play a role in the development of NODAT [2e5]. Several clinical studies have confirmed that NODAT induces tissue damage in the allograft shortly after transplantation, which leads to functional impairment in the
long term [6e8]. In our study, according to the criteria of the American Diabetes Association, diabetes is present if the fasting blood glucose level is 7 mmol/L or if the blood glucose level measured 2 h after the oral administration of 75 g glucose (oral glucose tolerance test, OGTT) is 11.1 mmol/L. Impaired fasting glucose (IFG) is defined as a fasting blood glucose level between 5.6 mmol/L and 6.9 mmol/L, whereas the normal value (N) for fasting blood glucose is <5.6 mmol/L or impaired glucose tolerance (IGT) (2-h values in the OGTT) between 7.8 mmol/L and 11.0 mmol/L (32). NODAT was diagnosed when the fasting glucose level was >7.1 mmol/L and/or when glucose
*Address correspondence to Bernadett Borda, MD, PhD, Department of Surgery, University of Szeged, Pécsi u. 6. 6720 Szeged, Hungary. E-mail: [email protected]
ª 2014 by Elsevier Inc. All rights reserved. 360 Park Avenue South, New York, NY 10010-1710
0041-1345/14/$esee front matter http://dx.doi.org/10.1016/j.transproceed.2014.05.057
Transplantation Proceedings, 46, 2155e2159 (2014)
2155
Severe intimal arteritis with at least 25% luminal area lost in 1 arterial cross section Arterial fibrinoid change and/or transmural arteritis with medial smooth muscle necrosis with lymphocytic inflammation
Quantitative Criteria for Intimal Arteritis
level was above 11.1 mmol/L 120 minutes after the 75-g OGTT [9]. The aim of our study was to compare the incidence of new-onset diabetes mellitus 1 year after kidney transplantation in patients taking cyclosporine A (CsA) and tacrolimus (Tac) and to compare the effect of new-onset diabetes on the function and histopathology of the allograft and on the changes in the Banff score.
Mild-to-moderate intimal arteritis in 1 arterial cross section
BORDA, MUNIR IBRAHIM, LENGYEL ET AL
No arteritis
2156
Mild-to-moderate PAS-positive hyaline thickening in 1 arteriole Moderate-to-severe PAS-positive hyaline thickening in >1 arteriole Severe PAS-positive hyaline thickening in many arterioles Glomerulitis in <25% of glomeruli
Abbreviation: PAS, periodic acid Schiff.
>50% of parenchyma inflamed Foci with >10 cells/tubular cross section or the presence of 2 areas of tubular basement membrane 3
2
Foci with 1 to 4 cells/tubular cross section or 10 tubular cells Foci with 5 to 10 cells/tubular cross section 1
26% to 50% of parenchyma inflamed
Segmental or global glomerulitis in about 25% to 75% of glomeruli Glomerulitis (mostly global) in >75% glomeruli
No PAS-positive hyaline thickening No glomerulitis
No or trivial interstitial inflammation (<10% of unscarred parenchyma) 10% to 25% of parenchyma inflamed cells No mononuclear cells in tubules 0
Quantitative Criteria for Arteriolar Hyaline Thickening Quantitative Criteria for the Early Type of Allograft Glomerulitis Quantitative Criteria for Mononuclear Cell Interstitial Inflammation Quantitative Criteria for Tubulitis Score
Our studies were conducted in the Department of Surgery, University of Szeged, Hungary. Zero-hour biopsy was performed in the case of all cadaver kidneys before transplantation. Patients who had no zero-hour biopsy did not agree to the biopsy in accordance with the protocol being performed, died during the study, had diabetes mellitus diagnosed before the transplantation, were younger than 18 years, or were living-donor recipients were excluded from the study. Two patients died during the study, and the kidney had to be removed in 4 cases; therefore, a total of 69 patients were enrolled in the study. Patients were randomly assigned to 2 groups; 1 group received CsA-based immunosuppression (n ¼ 35) and the other group received Tac-based IS (n ¼ 34). Fasting glucose level was measured in all patients before the transplantation, and patients having diabetes mellitus were excluded from the study. One year after the transplantation, check-up laboratory tests and OGTT were performed in all patients, and patients were classified into one of the following 3 groups on the basis of the glucose value: N, increased fasting glucose/IGT, and NODAT. In these groups, the effect of abnormal glucose metabolism on renal function and histopathology was evaluated. Functional changes of the kidney were assessed through the use of serum creatinine level (mmol/L), estimated glomerular filtration rate (eGFR; GFR calculated with the CKD-EPI formula [mL/min/ 1.73 m2]), and urea (mmol/L) values. Morphologic changes were confirmed with protocol biopsy 1 year after transplantation after informed consent was given. The ultrasound-guided protocol biopsy was performed (with prior consent) after the 1-year fasting laboratory testing. We used 16-G Tru-Cut needles and a biopsy gun to obtain tissue cylinders. Morphologic examinations included standard light microscopic staining (hematoxylin and eosin, periodic acid Schiff, trichrome, and methenamine silver), as well as immunofluorescence staining of frozen sections with the use of antibodies to human leukocyte class II antigens, complement 4d (C4d), C3, immunoglobulin (Ig)G, IgA, and IgM. Embedding for electron microscopy was performed in all cases, some of which underwent ultrastructural evaluation. Renal lesions were graded and diagnosed according to the 2003 modification of the Banff 97 classification. Histological changes were classified as acute cellular rejection (ACR), calcineurin inhibitor toxicity, and interstitial fibrosis/tubular atrophy (IF/TA) for grades II and III, compared with grade I, which was considered to be normal; we also sought changes associated with pyelonephritis and other diseases, for example, acute tubular necrosis, glomerulonephritis, and BK polyomavirus nephritis. The Banff score changes are glomerulitis [g] þ interstitial inflammation [i] þ tubulitis [t] þ arteriola hyalinosis [ah] þ intimal arteritis (v) (Table 1) [10]. Our study was approved by the Regional Human Biomedical Research Ethics Committee of the Albert Szent-Györgyi Clinical
Table 1. Specimen Adequacy and Lesion Scoring (Banff 97)
PATIENTS AND METHODS
CHANGES IN NEW-ONSET DIABETES AFTER KIDNEY TRANSPLANT
2157
Table 2. Glucose Metabolism Changes Between CsA and Tac One Year After Kidney Transplantation CsA (n ¼ 35)
Tac (n ¼ 34) OGTT 120 min
(n ¼ 69)
NODAT
4 (11%)
4 þ 1 ¼ 5 (14%)
7 (21%)
7 þ 2 ¼ 9 (26%)
14 (21%)
IFG/IGT
8 (23%)
7 þ 3 ¼ 10 (29%)
11 (32%)
10 þ 6 ¼ 15 (44%)
26 (37%)
23 (66%)
20 (57%)
16 (47%)
10 (30%)
29 (42%)
Changes
N
OGTT 120 min
Changes
Abbreviations: CsA, cyclosporine A; Tac, tacrolimus; NODAT, new-onset diabetes after transplantation; IFG/IGT, increased fasting glucose/impaired glucose tolerance; N, normal; OGTT, oral glucose tolerance test.
Center, University of Szeged (Reg. No. 17/2011). Each patient was provided with comprehensive information regarding the study.
Immunosuppressive Protocol The initial daily dose of Tac (0.20 mg/kg in 2 portions) was adjusted to target blood trough levels of 10e15 ng/mL at 6 weeks and 5e10 ng/mL thereafter. The initial CsA dose was 8e10 mg/kg daily in 2 portions with target blood levels at 2 hours after dosing of 1300e1600 ng/mL at month 1; 900e1300 ng/mL at months 2 and 3; 750e950 ng/mL at months 4e6; and 700 ng/mL thereafter.
Statistical Analysis Continuous variables were summarized with mean standard deviation, whereas categoric variables were presented with proportions and Student t test, or 1-way analysis of variance was used for group comparisons as appropriate. The normal distribution of samples was evaluated by means of the Kolmogorov-Smirnov test. Categoric data were analyzed with the use of c2 and Fisher exact tests. The multivariable dependences of NODAT categoric and continuous data were analyses with the use of logistic regression. A value of P < .005 was considered to be significant. SPSS version 15.0 (2007 SPSS, Inc, Chicago, Ill, United States) was used for the statistical analysis.
RESULTS
The results of fasting glucose measurement and OGTT performed 1 year after the transplantation were the following: NODAT, n ¼ 5 (14%); IFG/IGT, n ¼ 10 (29%); and N, n ¼ 20 (57%) in patients receiving CsA-based IS; NODAT, n ¼ 9 (26%); IFG/IGT, n ¼ 15 (44%); and N, n ¼ 11 (30%) in patients taking Tac. The incidence of diabetes was significantly different in the CsA group compared with the Tac group (P ¼ .0002). Examination of all patients revealed the following distribution regarding glucose metabolism: NODAT, 21%; IFG/IGT, 37%; and N, 42% (Table 2). Logistic regression showed that Tac increased the risk of the development of diabetes by 25% (Table 3). Laboratory tests revealed no significant difference in the albumin level but showed that uric acid was significantly different in NODAT patients compared with patients having normal glucose metabolism (462.2 137.3 vs 348.4 97, P ¼ .002). The age of the recipient was significantly different in diabetic patients compared with the normal group (55.7 10.2 vs 41.3 9.3; P ¼ .003). In the case of
renal function, serum creatinine, eGFR, and urea levels were not significantly different between the N and the NODAT groups 1 year after the transplantation (Table 4). Histological assessment of protocol biopsies performed in patients with different glucose metabolism levels detected ACR in 3 (22%), IF/TA in 5 (36%), and normal histology in 3 (21%) samples in the NODAT group. ACR (P ¼ .003), IF/TA (P ¼ .0001), and N (P ¼ .0002) values were significantly different between the normal and the NODAT group (Table 5). Changes in the Banff score revealed tubulitis in 11 of 14 cases in the NODAT group and in 10 of 29 cases in the normal group, and the difference was significant (P ¼ .015). In addition to [t], [i] was also significantly different in patients having diabetes compared with patients having normal glucose metabolism (9, 13% vs 6, 9%; P ¼ .05) (Table 6). DISCUSSION
It is known that the risk of diabetes is increased after kidney transplantation. The incidence of NODAT may be increased as a consequence of the combination of multiple risk factors. Valderhang et al [11] found that the incidence of NODAT was 14%. Several authors have shown that the most important risk factors of NODAT are immunosuppressive drugs, but family history, weight, and body mass index of the recipient are also essential [5,6,8,12]. In our study, it was shown that uric acid level was higher in the NODAT group, although both CNIs are associated with hyperuricemia. The incidence of NODAT after kidney transplantation was 21% in the patients enrolled in our study. In our clinical study, the diabetogenic effect of the immunosuppressive drugs CsA and Tac were evaluated. Significant difference was found in the diabetogenic effect Table 3. Results of Logistic Regression Analysis in the NODAT Group NODAT
Cyclosporine A Tacrolimus
P Value
OR
.077 .05
0.317 1.258
Abbreviations: NODAT, new-onset diabetes after transplantation; OR, odds ratio.
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BORDA, MUNIR IBRAHIM, LENGYEL ET AL Table 4. Laboratory Results of the Other Glucose Metabolism Groups NODAT (n ¼ 14) Mean SD
Age (years) Uric acid (mmol/L) Albumin (g/L) Urea (mmol/L) eGFR (mL/min/1.73 m2) Serum creatinine (mmol/L)
55.7 462.2 46.6 14.2 36.7 178.5
IFG/IGT (n ¼ 26) Mean SD
10.2 137.3 3.2 5.8 13.1 58.7
43 372.5 46.27 12.51 39.51 186.50
8.1 86.3 4.49 6.17 16.24 62.70
N (n ¼ 29) Mean SD
P Value (N vs NODAT)
.003 .002 .568 .134 .583 .236
41.3 348.4 47.15 11.81 40.73 174.69
9.3 97.5 3.65 7.58 13.06 122.60
Abbreviations: NODAT, new-onset diabetes after transplantation; IFG/IGT, increased fasting glucose/impaired glucose tolerance; N, normal; SD, standard deviation; eGFR, estimated glomerular filtration rate.
of the IS drugs Tac and CsA (26% vs 14%). Our results may confirm that Tac exerts a stronger diabetogenic effect. CsA appears to be less diabetogenic than Tac, but both agents may have a direct impact on the transcriptional regulation of insulin gene expression in the pancreatic b cells. The exact mechanism of calcineurin inhibitoreinduced toxicity to b cells is unknown. The diabetogenic effect of Tac may be reversible, as evidenced by observations that impaired insulin secretion was reversed 3 days after Tac discontinuation, and insulin secretion improved after the reduction of Tac through blood concentration. With the above understanding, in the following sections, genes related to diabetes or to the mechanism of developing diabetes are compared with the genes associated with calcineurin inhibitoreinduced diabetes [12]. The incidence of diabetes is 33.6% in the case of Tac and 26% in the case of cyclosporine in the study of Vincenti et al [5]. Calcineurin inhibitors have also been associated with posttransplantation diabetes. Steroids produce increased insulin resistance, whereas calcineurin inhibitors primarily decrease insulin secretion. CsA appears to be less diabetogenic than Tac, but both agents may have a direct impact on the transcriptional regulation of insulin gene expression in pancreatic b cells. The exact mechanism of calcineurin inhibitoreinduced toxicity to b cells is unknown. The diabetogenic effect of Tac may be reversible, as evidenced by observations that impaired insulin secretion was reversed 3 days after Tac discontinuation and that insulin secretion improved after the reduction of Tac through blood concentration. With the above understanding, in the following sections, genes related to diabetes or to the mechanism of developing diabetes are compared with the genes associated with calcineurin inhibitoreinduced diabetes [7]. Schiel et al [4] did not find significant differences in serum creatinine level and eGFR 1 year after kidney transplantation in patients having diabetes and patients with normal metabolism. In our clinical study, there were no
significant differences in the case of creatinine, urea, and eGFR between the N and the NODAT groups; however, the age of the recipient was significantly different between the two groups. In contrast to our functional results, morphologic abnormalities showed that ACR and IF/TA were significantly increased in the NODAT group compared with patients having normal carbohydrate metabolism. One year after kidney transplantation, diabetic nephropathy (especially mesangial matrix increase and arteriola hyalinosis) does not develop; however, permanent hyperglycemia may result in morphologic changes in the allograft. In IF/TA, hyperglycemia may lead to fibrogenesis by decreasing the number of functioning nephrons. Arif et al [13] found that IF/TA is significantly different between diabetic and normal patients (P < .001). Regarding the Banff score, the incidence of tubulitis [t] and interstitial inflammation [i] was significantly increased in patients having diabetes compared with that in normal patients. Kaminska et al [14] showed in their study that arteriolar hyalinosis and intimal arteritis correlate with the serum creatinine level; however, tubulitis and interstitial inflammation are independent of the serum creatinine level. Diabetes not diagnosed and treated in time not only damages the graft but increases the cardiovascular risk as well. In the case of kidney recipients, long-term survival of the graft may be increased and the cardiovascular risk may be decreased with diagnosing and treating NODAT in time. On the basis of the studies of Ger} o et al [15], microand macro-angiopathy developed as a complication of NODAT significantly decrease the survival of the renal allograft: micro-angiopathy leads to early renal failure, whereas macro-angiopathy increases the risk of coronary thrombosis and stroke. Proper evaluation of the risk status should be emphasized in patient care and when selecting immunosuppressive therapy. Regular control of carbohydrate metabolism is essential, especially in high-risk patients. In the case of impaired carbohydrate metabolism
Table 5. Protocol Biopsy Results NODAT (n ¼ 14) IFG/IGT (n ¼ 26) N (n ¼ 29) P value (N vs NODAT)
ACR
IF/TA (Grades II and III)
CNI-tox
PN
Other
Normal
3 (22%) 2 (8%) 2 (7%) .003
5 (36%) 4 (15%) 3 (10%) .0001
1 (7%) 2 (8%) 3 (10%) .143
1 (7%) 2 (8%) 2 (7%) .063
1 (7%) 3 (11%) 4 (14%) .056
3 (21%) 13 (50%) 15 (52%) .0002
Abbreviations: ACR, acute cellular rejection; IF/TA, interstitial fibrosis/tubular atrophia; CNI-tox, calcineurin inhibitor toxicity; PN, pyelonephritis; NODAT, new-onset diabetes after transplantation; IFG/IGT, increased fasting glucose/impaired glucose tolerance; N, normal.
CHANGES IN NEW-ONSET DIABETES AFTER KIDNEY TRANSPLANT Table 6. Banff Score Changes in the Other Carbohydrate Metabolism Groups Banff Score
Glomerulitis 0 1e3 Intimal arteritis 0 1e3 Tubulitis 0 1e3 Interstitial inflammation 0 1e3 Arteriolar hyaline thickening 0 1e3
NODAT (n ¼ 14)
IFG/IGT (n ¼ 26)
N (n ¼ 29)
10 (15%) 4 (6%)
19 (27%) 7 (10%)
23 (33%) 6 (9%)
9 (13%) 5 (7%)
14 (20%) 12 (18%)
18 (26%) 11 (16%)
3 (4%) 11 (16%)*
17 (25%) 9 (13%)
19 (27%) 10 (15%)
5 (7%) 9 (13%)*
22 (32%) 4 (6%)
23 (33%) 6 (9%)
19 (27%) 7 (10%)
20 (29%) 9 (13%)
10 (15%) 4 (6%)
Abbreviations: NODAT, new-onset diabetes after transplantation; IFG/IGT, increased fasting glucose/impaired glucose tolerance; N, normal. *NODAT vs N betegek között; tubulitis, P ¼ .015; intimal arteritis. P ¼ .05.
(development of IFG or IGT), regular diabetologic care is crucial. Interdisciplinary care of kidney recipients should be centralized and performed by a health care team ordif not possibledat least 1 check-up should be performed every year. Harmonized care may be essential in preserving the function of the allograft as well as in preventing macrovascular complications and in decreasing mortality rates in the long term. REFERENCES [1] Cosio FG, Kudva Y, Velde M, et al. New onset hyperglycemia and diabetes are associated with increased cardiovascular risk after kidney transplantation. Kidney Int 2005;67:2415.
2159
[2] Ossareh S, Nassem S, Faraj MA. Frequency and risk factors for posttransplant diabetes mellitus in Irianian renal transplant patients. Transplant Proc 2009;41:2814. [3] Burroughs TE, Swindle J, Takemoto S, et al. Diabetic complications associated with new-onset diabetes mellitus in renal transplant recipients. Transplantation 2007;83:1027. [4] Schiel R, Heinrich S, Steiner T, et al. Post-transplant diabetes mellitus: risk factors, frequency of transplant rejections, and longterm prognosis. Clin Exp Nephrol 2005;9:164. [5] Vincenti F, Friman S, Scheuermann E, et al. Results of an international, randomized trial comparing glucose metabolism discorders and outcome with cyclosporine versus tacrolimus. Am J Transplant 2007;7:1506. [6] Borda B, Szederkényi E, Lengyel C, et al. Functional and histopathological changes in renal transplant patients with newonset diabetes and dyslipidemia. Transplant Proc 2011;43:1254. [7] Helanterä I, Ortiz F, Räisänen-Sokolowski A, et al. Impact of glucose metabolism abnormalities on histopathological changes in kidney transplant protocol biopsies. Transpl Int 2010;4:374. [8] Borda B, Lengyel C, Szederkényi E, et al. Post-transplant diabetes mellitus: risk factors and effects on the function and morphology of the allograft. Acta Physiol Hung 2012;99:206. [9] American Diabetes Association. Diagnosis and classification of diabetes mellitus. Diabetes Care 2012;35(Suppl 1):S64. [10] Racusen L, Colvin RB, Solez K, et al. The Banff 97 working classification of renal allograft pathology. Kidney Int 1999;55:713. [11] Valderhang TG, Jenssen T, Hartmann, et al. Fasting plasma glucose and glycosylated hemoglobin in the screening for diabetes mellitus after renal transplantation. Transplantation 2009;88:429. [12] Davidson J, Wilkinson A, Dantal J, et al. New-onset diabetes after transplantation: 2003 international consensus guidelines. Transplantation 2003;75(Suppl 10):SS3. [13] Arif M, Arif MK, Arif MS. An evoluation of renal biopsy in type-II diabetic patients. J Coll Physicians Surg Pak 2009;19: 627. [14] Kaminska D, Bernat B, Mazanowska O, et al. Predictive value of Banff score of early kidney allograft biopsies for 1-year graft survival. Transplant Proc 2006;38:59. [15] Ger} o L, Földes K. A poszttranszplantációs diabetes mellitusról. Diabetologia Hungarica 1995;3:181.
ABSTRACT Background. New-onset diabetes after transplantation (NODAT) is one of the most common complications after kidney transplantation. Methods. Patients were randomly assigned to receive cyclosporine Aebased or tacrolimusbased immunosuppression. Fasting and oral glucose tolerance tests were performed, and the patients were assigned to one of the following 3 groups, on the basis of the results: normal, impaired fasting glucose/impaired glucose tolerance, or NODAT. NODAT developed in 14% of patients receiving cyclosporine Aebased immunosuppression and in 26% of patients taking tacrolimus (P ¼ .0002). Results. Albumin levels were similar, but uric acid level (P ¼ .002) and the age of the recipient (P ¼ .003) were significantly different between the diabetic and the normal groups. Evaluation of tissue samples revealed that acute cellular rejection and interstitial fibrosis/tubular atrophy were significantly different in the NODAT group. Changes in the Banff score provided significant difference regarding tubulitis and interstitial inflammation (P ¼ .05). Conclusions. The pathological effect of new-onset diabetes after kidney transplantation can be detected in the morphology of the renal allograft earlier, before the development of any sign of functional impairment.
N
EW-ONSET diabetes mellitus after transplantation (NODAT) is one of the most common complications after kidney transplantation. The diagnosis of NODAT is often late or missed; therefore, it impairs the implanted renal allograft. Not only does untreated NODAT negatively influence the allograft, but it increases the risk of cardiovascular diseases (ischemic heart disease, hypertension, and hyperlipidemia) and death [1e4]. NODAT is the same risk factor of cardiovascular diseases as diabetes diagnosed before the transplantation [1]. Its etiopathogenesis is complex; endogenous factors, such as severe obesity, positive family history, age, hepatitis C and cytomegalovirus infection, and immunosuppressive (IS) therapy play a role in the development of NODAT [2e5]. Several clinical studies have confirmed that NODAT induces tissue damage in the allograft shortly after transplantation, which leads to functional impairment in the
long term [6e8]. In our study, according to the criteria of the American Diabetes Association, diabetes is present if the fasting blood glucose level is 7 mmol/L or if the blood glucose level measured 2 h after the oral administration of 75 g glucose (oral glucose tolerance test, OGTT) is 11.1 mmol/L. Impaired fasting glucose (IFG) is defined as a fasting blood glucose level between 5.6 mmol/L and 6.9 mmol/L, whereas the normal value (N) for fasting blood glucose is <5.6 mmol/L or impaired glucose tolerance (IGT) (2-h values in the OGTT) between 7.8 mmol/L and 11.0 mmol/L (32). NODAT was diagnosed when the fasting glucose level was >7.1 mmol/L and/or when glucose
*Address correspondence to Bernadett Borda, MD, PhD, Department of Surgery, University of Szeged, Pécsi u. 6. 6720 Szeged, Hungary. E-mail: [email protected]
ª 2014 by Elsevier Inc. All rights reserved. 360 Park Avenue South, New York, NY 10010-1710
0041-1345/14/$esee front matter http://dx.doi.org/10.1016/j.transproceed.2014.05.057
Transplantation Proceedings, 46, 2155e2159 (2014)
2155
Severe intimal arteritis with at least 25% luminal area lost in 1 arterial cross section Arterial fibrinoid change and/or transmural arteritis with medial smooth muscle necrosis with lymphocytic inflammation
Quantitative Criteria for Intimal Arteritis
level was above 11.1 mmol/L 120 minutes after the 75-g OGTT [9]. The aim of our study was to compare the incidence of new-onset diabetes mellitus 1 year after kidney transplantation in patients taking cyclosporine A (CsA) and tacrolimus (Tac) and to compare the effect of new-onset diabetes on the function and histopathology of the allograft and on the changes in the Banff score.
Mild-to-moderate intimal arteritis in 1 arterial cross section
BORDA, MUNIR IBRAHIM, LENGYEL ET AL
No arteritis
2156
Mild-to-moderate PAS-positive hyaline thickening in 1 arteriole Moderate-to-severe PAS-positive hyaline thickening in >1 arteriole Severe PAS-positive hyaline thickening in many arterioles Glomerulitis in <25% of glomeruli
Abbreviation: PAS, periodic acid Schiff.
>50% of parenchyma inflamed Foci with >10 cells/tubular cross section or the presence of 2 areas of tubular basement membrane 3
2
Foci with 1 to 4 cells/tubular cross section or 10 tubular cells Foci with 5 to 10 cells/tubular cross section 1
26% to 50% of parenchyma inflamed
Segmental or global glomerulitis in about 25% to 75% of glomeruli Glomerulitis (mostly global) in >75% glomeruli
No PAS-positive hyaline thickening No glomerulitis
No or trivial interstitial inflammation (<10% of unscarred parenchyma) 10% to 25% of parenchyma inflamed cells No mononuclear cells in tubules 0
Quantitative Criteria for Arteriolar Hyaline Thickening Quantitative Criteria for the Early Type of Allograft Glomerulitis Quantitative Criteria for Mononuclear Cell Interstitial Inflammation Quantitative Criteria for Tubulitis Score
Our studies were conducted in the Department of Surgery, University of Szeged, Hungary. Zero-hour biopsy was performed in the case of all cadaver kidneys before transplantation. Patients who had no zero-hour biopsy did not agree to the biopsy in accordance with the protocol being performed, died during the study, had diabetes mellitus diagnosed before the transplantation, were younger than 18 years, or were living-donor recipients were excluded from the study. Two patients died during the study, and the kidney had to be removed in 4 cases; therefore, a total of 69 patients were enrolled in the study. Patients were randomly assigned to 2 groups; 1 group received CsA-based immunosuppression (n ¼ 35) and the other group received Tac-based IS (n ¼ 34). Fasting glucose level was measured in all patients before the transplantation, and patients having diabetes mellitus were excluded from the study. One year after the transplantation, check-up laboratory tests and OGTT were performed in all patients, and patients were classified into one of the following 3 groups on the basis of the glucose value: N, increased fasting glucose/IGT, and NODAT. In these groups, the effect of abnormal glucose metabolism on renal function and histopathology was evaluated. Functional changes of the kidney were assessed through the use of serum creatinine level (mmol/L), estimated glomerular filtration rate (eGFR; GFR calculated with the CKD-EPI formula [mL/min/ 1.73 m2]), and urea (mmol/L) values. Morphologic changes were confirmed with protocol biopsy 1 year after transplantation after informed consent was given. The ultrasound-guided protocol biopsy was performed (with prior consent) after the 1-year fasting laboratory testing. We used 16-G Tru-Cut needles and a biopsy gun to obtain tissue cylinders. Morphologic examinations included standard light microscopic staining (hematoxylin and eosin, periodic acid Schiff, trichrome, and methenamine silver), as well as immunofluorescence staining of frozen sections with the use of antibodies to human leukocyte class II antigens, complement 4d (C4d), C3, immunoglobulin (Ig)G, IgA, and IgM. Embedding for electron microscopy was performed in all cases, some of which underwent ultrastructural evaluation. Renal lesions were graded and diagnosed according to the 2003 modification of the Banff 97 classification. Histological changes were classified as acute cellular rejection (ACR), calcineurin inhibitor toxicity, and interstitial fibrosis/tubular atrophy (IF/TA) for grades II and III, compared with grade I, which was considered to be normal; we also sought changes associated with pyelonephritis and other diseases, for example, acute tubular necrosis, glomerulonephritis, and BK polyomavirus nephritis. The Banff score changes are glomerulitis [g] þ interstitial inflammation [i] þ tubulitis [t] þ arteriola hyalinosis [ah] þ intimal arteritis (v) (Table 1) [10]. Our study was approved by the Regional Human Biomedical Research Ethics Committee of the Albert Szent-Györgyi Clinical
Table 1. Specimen Adequacy and Lesion Scoring (Banff 97)
PATIENTS AND METHODS
CHANGES IN NEW-ONSET DIABETES AFTER KIDNEY TRANSPLANT
2157
Table 2. Glucose Metabolism Changes Between CsA and Tac One Year After Kidney Transplantation CsA (n ¼ 35)
Tac (n ¼ 34) OGTT 120 min
(n ¼ 69)
NODAT
4 (11%)
4 þ 1 ¼ 5 (14%)
7 (21%)
7 þ 2 ¼ 9 (26%)
14 (21%)
IFG/IGT
8 (23%)
7 þ 3 ¼ 10 (29%)
11 (32%)
10 þ 6 ¼ 15 (44%)
26 (37%)
23 (66%)
20 (57%)
16 (47%)
10 (30%)
29 (42%)
Changes
N
OGTT 120 min
Changes
Abbreviations: CsA, cyclosporine A; Tac, tacrolimus; NODAT, new-onset diabetes after transplantation; IFG/IGT, increased fasting glucose/impaired glucose tolerance; N, normal; OGTT, oral glucose tolerance test.
Center, University of Szeged (Reg. No. 17/2011). Each patient was provided with comprehensive information regarding the study.
Immunosuppressive Protocol The initial daily dose of Tac (0.20 mg/kg in 2 portions) was adjusted to target blood trough levels of 10e15 ng/mL at 6 weeks and 5e10 ng/mL thereafter. The initial CsA dose was 8e10 mg/kg daily in 2 portions with target blood levels at 2 hours after dosing of 1300e1600 ng/mL at month 1; 900e1300 ng/mL at months 2 and 3; 750e950 ng/mL at months 4e6; and 700 ng/mL thereafter.
Statistical Analysis Continuous variables were summarized with mean standard deviation, whereas categoric variables were presented with proportions and Student t test, or 1-way analysis of variance was used for group comparisons as appropriate. The normal distribution of samples was evaluated by means of the Kolmogorov-Smirnov test. Categoric data were analyzed with the use of c2 and Fisher exact tests. The multivariable dependences of NODAT categoric and continuous data were analyses with the use of logistic regression. A value of P < .005 was considered to be significant. SPSS version 15.0 (2007 SPSS, Inc, Chicago, Ill, United States) was used for the statistical analysis.
RESULTS
The results of fasting glucose measurement and OGTT performed 1 year after the transplantation were the following: NODAT, n ¼ 5 (14%); IFG/IGT, n ¼ 10 (29%); and N, n ¼ 20 (57%) in patients receiving CsA-based IS; NODAT, n ¼ 9 (26%); IFG/IGT, n ¼ 15 (44%); and N, n ¼ 11 (30%) in patients taking Tac. The incidence of diabetes was significantly different in the CsA group compared with the Tac group (P ¼ .0002). Examination of all patients revealed the following distribution regarding glucose metabolism: NODAT, 21%; IFG/IGT, 37%; and N, 42% (Table 2). Logistic regression showed that Tac increased the risk of the development of diabetes by 25% (Table 3). Laboratory tests revealed no significant difference in the albumin level but showed that uric acid was significantly different in NODAT patients compared with patients having normal glucose metabolism (462.2 137.3 vs 348.4 97, P ¼ .002). The age of the recipient was significantly different in diabetic patients compared with the normal group (55.7 10.2 vs 41.3 9.3; P ¼ .003). In the case of
renal function, serum creatinine, eGFR, and urea levels were not significantly different between the N and the NODAT groups 1 year after the transplantation (Table 4). Histological assessment of protocol biopsies performed in patients with different glucose metabolism levels detected ACR in 3 (22%), IF/TA in 5 (36%), and normal histology in 3 (21%) samples in the NODAT group. ACR (P ¼ .003), IF/TA (P ¼ .0001), and N (P ¼ .0002) values were significantly different between the normal and the NODAT group (Table 5). Changes in the Banff score revealed tubulitis in 11 of 14 cases in the NODAT group and in 10 of 29 cases in the normal group, and the difference was significant (P ¼ .015). In addition to [t], [i] was also significantly different in patients having diabetes compared with patients having normal glucose metabolism (9, 13% vs 6, 9%; P ¼ .05) (Table 6). DISCUSSION
It is known that the risk of diabetes is increased after kidney transplantation. The incidence of NODAT may be increased as a consequence of the combination of multiple risk factors. Valderhang et al [11] found that the incidence of NODAT was 14%. Several authors have shown that the most important risk factors of NODAT are immunosuppressive drugs, but family history, weight, and body mass index of the recipient are also essential [5,6,8,12]. In our study, it was shown that uric acid level was higher in the NODAT group, although both CNIs are associated with hyperuricemia. The incidence of NODAT after kidney transplantation was 21% in the patients enrolled in our study. In our clinical study, the diabetogenic effect of the immunosuppressive drugs CsA and Tac were evaluated. Significant difference was found in the diabetogenic effect Table 3. Results of Logistic Regression Analysis in the NODAT Group NODAT
Cyclosporine A Tacrolimus
P Value
OR
.077 .05
0.317 1.258
Abbreviations: NODAT, new-onset diabetes after transplantation; OR, odds ratio.
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BORDA, MUNIR IBRAHIM, LENGYEL ET AL Table 4. Laboratory Results of the Other Glucose Metabolism Groups NODAT (n ¼ 14) Mean SD
Age (years) Uric acid (mmol/L) Albumin (g/L) Urea (mmol/L) eGFR (mL/min/1.73 m2) Serum creatinine (mmol/L)
55.7 462.2 46.6 14.2 36.7 178.5
IFG/IGT (n ¼ 26) Mean SD
10.2 137.3 3.2 5.8 13.1 58.7
43 372.5 46.27 12.51 39.51 186.50
8.1 86.3 4.49 6.17 16.24 62.70
N (n ¼ 29) Mean SD
P Value (N vs NODAT)
.003 .002 .568 .134 .583 .236
41.3 348.4 47.15 11.81 40.73 174.69
9.3 97.5 3.65 7.58 13.06 122.60
Abbreviations: NODAT, new-onset diabetes after transplantation; IFG/IGT, increased fasting glucose/impaired glucose tolerance; N, normal; SD, standard deviation; eGFR, estimated glomerular filtration rate.
of the IS drugs Tac and CsA (26% vs 14%). Our results may confirm that Tac exerts a stronger diabetogenic effect. CsA appears to be less diabetogenic than Tac, but both agents may have a direct impact on the transcriptional regulation of insulin gene expression in the pancreatic b cells. The exact mechanism of calcineurin inhibitoreinduced toxicity to b cells is unknown. The diabetogenic effect of Tac may be reversible, as evidenced by observations that impaired insulin secretion was reversed 3 days after Tac discontinuation, and insulin secretion improved after the reduction of Tac through blood concentration. With the above understanding, in the following sections, genes related to diabetes or to the mechanism of developing diabetes are compared with the genes associated with calcineurin inhibitoreinduced diabetes [12]. The incidence of diabetes is 33.6% in the case of Tac and 26% in the case of cyclosporine in the study of Vincenti et al [5]. Calcineurin inhibitors have also been associated with posttransplantation diabetes. Steroids produce increased insulin resistance, whereas calcineurin inhibitors primarily decrease insulin secretion. CsA appears to be less diabetogenic than Tac, but both agents may have a direct impact on the transcriptional regulation of insulin gene expression in pancreatic b cells. The exact mechanism of calcineurin inhibitoreinduced toxicity to b cells is unknown. The diabetogenic effect of Tac may be reversible, as evidenced by observations that impaired insulin secretion was reversed 3 days after Tac discontinuation and that insulin secretion improved after the reduction of Tac through blood concentration. With the above understanding, in the following sections, genes related to diabetes or to the mechanism of developing diabetes are compared with the genes associated with calcineurin inhibitoreinduced diabetes [7]. Schiel et al [4] did not find significant differences in serum creatinine level and eGFR 1 year after kidney transplantation in patients having diabetes and patients with normal metabolism. In our clinical study, there were no
significant differences in the case of creatinine, urea, and eGFR between the N and the NODAT groups; however, the age of the recipient was significantly different between the two groups. In contrast to our functional results, morphologic abnormalities showed that ACR and IF/TA were significantly increased in the NODAT group compared with patients having normal carbohydrate metabolism. One year after kidney transplantation, diabetic nephropathy (especially mesangial matrix increase and arteriola hyalinosis) does not develop; however, permanent hyperglycemia may result in morphologic changes in the allograft. In IF/TA, hyperglycemia may lead to fibrogenesis by decreasing the number of functioning nephrons. Arif et al [13] found that IF/TA is significantly different between diabetic and normal patients (P < .001). Regarding the Banff score, the incidence of tubulitis [t] and interstitial inflammation [i] was significantly increased in patients having diabetes compared with that in normal patients. Kaminska et al [14] showed in their study that arteriolar hyalinosis and intimal arteritis correlate with the serum creatinine level; however, tubulitis and interstitial inflammation are independent of the serum creatinine level. Diabetes not diagnosed and treated in time not only damages the graft but increases the cardiovascular risk as well. In the case of kidney recipients, long-term survival of the graft may be increased and the cardiovascular risk may be decreased with diagnosing and treating NODAT in time. On the basis of the studies of Ger} o et al [15], microand macro-angiopathy developed as a complication of NODAT significantly decrease the survival of the renal allograft: micro-angiopathy leads to early renal failure, whereas macro-angiopathy increases the risk of coronary thrombosis and stroke. Proper evaluation of the risk status should be emphasized in patient care and when selecting immunosuppressive therapy. Regular control of carbohydrate metabolism is essential, especially in high-risk patients. In the case of impaired carbohydrate metabolism
Table 5. Protocol Biopsy Results NODAT (n ¼ 14) IFG/IGT (n ¼ 26) N (n ¼ 29) P value (N vs NODAT)
ACR
IF/TA (Grades II and III)
CNI-tox
PN
Other
Normal
3 (22%) 2 (8%) 2 (7%) .003
5 (36%) 4 (15%) 3 (10%) .0001
1 (7%) 2 (8%) 3 (10%) .143
1 (7%) 2 (8%) 2 (7%) .063
1 (7%) 3 (11%) 4 (14%) .056
3 (21%) 13 (50%) 15 (52%) .0002
Abbreviations: ACR, acute cellular rejection; IF/TA, interstitial fibrosis/tubular atrophia; CNI-tox, calcineurin inhibitor toxicity; PN, pyelonephritis; NODAT, new-onset diabetes after transplantation; IFG/IGT, increased fasting glucose/impaired glucose tolerance; N, normal.
CHANGES IN NEW-ONSET DIABETES AFTER KIDNEY TRANSPLANT Table 6. Banff Score Changes in the Other Carbohydrate Metabolism Groups Banff Score
Glomerulitis 0 1e3 Intimal arteritis 0 1e3 Tubulitis 0 1e3 Interstitial inflammation 0 1e3 Arteriolar hyaline thickening 0 1e3
NODAT (n ¼ 14)
IFG/IGT (n ¼ 26)
N (n ¼ 29)
10 (15%) 4 (6%)
19 (27%) 7 (10%)
23 (33%) 6 (9%)
9 (13%) 5 (7%)
14 (20%) 12 (18%)
18 (26%) 11 (16%)
3 (4%) 11 (16%)*
17 (25%) 9 (13%)
19 (27%) 10 (15%)
5 (7%) 9 (13%)*
22 (32%) 4 (6%)
23 (33%) 6 (9%)
19 (27%) 7 (10%)
20 (29%) 9 (13%)
10 (15%) 4 (6%)
Abbreviations: NODAT, new-onset diabetes after transplantation; IFG/IGT, increased fasting glucose/impaired glucose tolerance; N, normal. *NODAT vs N betegek között; tubulitis, P ¼ .015; intimal arteritis. P ¼ .05.
(development of IFG or IGT), regular diabetologic care is crucial. Interdisciplinary care of kidney recipients should be centralized and performed by a health care team ordif not possibledat least 1 check-up should be performed every year. Harmonized care may be essential in preserving the function of the allograft as well as in preventing macrovascular complications and in decreasing mortality rates in the long term. REFERENCES [1] Cosio FG, Kudva Y, Velde M, et al. New onset hyperglycemia and diabetes are associated with increased cardiovascular risk after kidney transplantation. Kidney Int 2005;67:2415.
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[2] Ossareh S, Nassem S, Faraj MA. Frequency and risk factors for posttransplant diabetes mellitus in Irianian renal transplant patients. Transplant Proc 2009;41:2814. [3] Burroughs TE, Swindle J, Takemoto S, et al. Diabetic complications associated with new-onset diabetes mellitus in renal transplant recipients. Transplantation 2007;83:1027. [4] Schiel R, Heinrich S, Steiner T, et al. Post-transplant diabetes mellitus: risk factors, frequency of transplant rejections, and longterm prognosis. Clin Exp Nephrol 2005;9:164. [5] Vincenti F, Friman S, Scheuermann E, et al. Results of an international, randomized trial comparing glucose metabolism discorders and outcome with cyclosporine versus tacrolimus. Am J Transplant 2007;7:1506. [6] Borda B, Szederkényi E, Lengyel C, et al. Functional and histopathological changes in renal transplant patients with newonset diabetes and dyslipidemia. Transplant Proc 2011;43:1254. [7] Helanterä I, Ortiz F, Räisänen-Sokolowski A, et al. Impact of glucose metabolism abnormalities on histopathological changes in kidney transplant protocol biopsies. Transpl Int 2010;4:374. [8] Borda B, Lengyel C, Szederkényi E, et al. Post-transplant diabetes mellitus: risk factors and effects on the function and morphology of the allograft. Acta Physiol Hung 2012;99:206. [9] American Diabetes Association. Diagnosis and classification of diabetes mellitus. Diabetes Care 2012;35(Suppl 1):S64. [10] Racusen L, Colvin RB, Solez K, et al. The Banff 97 working classification of renal allograft pathology. Kidney Int 1999;55:713. [11] Valderhang TG, Jenssen T, Hartmann, et al. Fasting plasma glucose and glycosylated hemoglobin in the screening for diabetes mellitus after renal transplantation. Transplantation 2009;88:429. [12] Davidson J, Wilkinson A, Dantal J, et al. New-onset diabetes after transplantation: 2003 international consensus guidelines. Transplantation 2003;75(Suppl 10):SS3. [13] Arif M, Arif MK, Arif MS. An evoluation of renal biopsy in type-II diabetic patients. J Coll Physicians Surg Pak 2009;19: 627. [14] Kaminska D, Bernat B, Mazanowska O, et al. Predictive value of Banff score of early kidney allograft biopsies for 1-year graft survival. Transplant Proc 2006;38:59. [15] Ger} o L, Földes K. A poszttranszplantációs diabetes mellitusról. Diabetologia Hungarica 1995;3:181.