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The activity of γ-glutamyl transferase in the serum of multiple sclerosis and other neurological diseases
211
Clinica Chimica Acta, 79 (1977) 211-217 @ Elsevier/North-Holland Biomedical Press
CCA 8781
THE ACTIVITY OF y-GLUTAMYL TRANSFERASE IN THE SERUM OF MULTIPLE SCLEROSIS AND OTHER NEUROLOGICAL DISEASES
H.P. RIEDER
*, HEIDI ZURFLUH
Neurologische
Universitiitsklinik, Forschungslaboratorium,
(Received
March 18th,
and SILVIA
JEGGE CH-4051 Base1 (Switzerland)
1977)
Summary
1. In the sera of 142 neurological patients, including 35 cases with multiple sclerosis (MS), and 20 normal controls the y-glutamyltransferase (y-GT) activity was determined. The result of this investigation was compared with the “combined hippuric acid test” formerly often used in MS patients. 2. The MS patients are the only group which significantly differs from the normal controls. There are also small differences between them and some of the other neurological patient groups. About one-third of the MS patients show moderately pathological serum activites. On the other hand, patients with a definite liver affection, especially chronic alcoholics, regularly show an even more important elevation of the values, which makes this test a sensitive tool for the screening of alcohol-induced liver intoxications. 3. Although the y-GT test in not quite as sensitive in indicating organic defects in MS patients, it seems to reflect a disturbed liver function in the same way as the more complicated “combined hippuric acid test”. It may therefore be used as a simple tool for finding and following up organic defects in MS patients.
Introduction
In 1952 Georgi and coworkers [l] found that there is a certain disturbance of liver function in patients with multiple sclerosis, particularly in the state of acute exacerbation or chronically active progression of the disease [2]. For this investigation they chose the hippuric acid test, which was often used at that time, particularly in its combined application as a test for glycine availability. This laborious test, which measures the detoxication of ingested benzoic acid by endogenous glycine, aims at measuring a specific function of the liver. * Address for correspondence: Basel. Switzerland.
Dr. H.P. Rieder,
Neurologische
Univ. Klinik. Socinstrasse
55. CH-4051
212
It is therefore obviously able to indicate a more subtle dysfunction than either the determiaation of bilirubin or the bromosuIfophth~ein-test, which were performed for comparison at that time [3]. However, we cannot expect the hippuric acid test to be diagnostically specific for a certain disease, since similar liver disturbances are found in schizophrenia [4], chronic alcoholism [5f and other neurofogieaI diseases [ 61 e+Moreover a significant temporary disturbance has also been demonstrated in the psychosis provoked by 0.5 g mescaline or 100-125 lg LSD [7], a fact worth remembering in these days of uncontrolled drug consumption. Since that time there have been many advances in liver diagnostics. As well as the tr~saminases, which have been known for a long time, ~-gIu~myItr~sferease in serum has been recognised as an especially good indicator of the degree of disturbance in liver function [8-l?‘]; its determination now belongs to the programme of the clinical chemical laboratory. On the other hand the hippuric acid test and its variants have fallen out of use, as they are both too expensive for the laboratory and disagreeable for the patient. We were therefore interested in finding out to what extent the liver-specific y_GT test could replace the test for glycine availability in the differential diagnosis of MS and other neurological diseases_ We are aware that some American authors [lS f have aIready touched on this question in 1973, but they neither specified the sex of the patients examined nor considered the important sex difference of the normal values. Their results may therefore be misleading.
The enzyme activity in the sera of the following patients was determined in immediately or after preservation at -20°C until the day of determination; a previous comparative study no change of activity was found after storage in this way. The patients are subdivided into the following groups (number of cases in parenthesis) MS: (35) multiple sclerosis TU: ( 8) brain or spinal tumour VPE: (15) vascular, posttraumatic and/or epileptic brain affection DH: (22) discus hernia and discopathy (16) Parkinson’s disease PA: DIV: ( 7) various other neurological diseases (14) alcoholism and other disturbed liver function AL: N: (20) healthy control persons for comparison For the assay of y-Gt activity the commercial test kits of Roche and Boehringer were used Cp-nitranilide-method with glycylglycine as co-substrate); measurement at 405 nm and 25°C. In about hdf of the cases the trsnsaminases * and alkaline phosphatase ** were determined at the same time and occasionlrlly also bilirubin *. In order to compare different tests, or groups of patients with different sex compositions, * %iochemica-tesE_com~~~tions%oehrmp?r,Mannkeim, ** Diignostica Merk. Darmstadt. G.F.R., kinetic test.
G.F.R.
213
we have used a special index (individual value/upper limit of the normal value of the corresponding sex) instead of the volume activity, i.e. the absolute concentration U/l. Thus the upper normal limit of the index equals 1.0 for both sexes and all methods. Results a. Reproducibility From 43 double assays during the whole investigation, we find a serial standard deviation of Sd = 0.57 U/l (V = 3.3%). The deviation from day to day of a control series with 39 determinations is 1.25 U/l (V = 8.7%). b. Normal values and limits Because of the well-known sex difference we must define different normal limits for men and women before computing the index values. In so doing we should first ask to what extent the normal values which we have found correspond with those in the literature, in order to be sure that their use in calculating the index is justified. Table I compares the data of various authors. It shows that men, contrary to some other suggestions [21], have on the average about 44% higher values than women. Neglecting the lowest and highest extreme values, most ratios from the groups under investigation fall into the range of 1.3-1.6. Our normal group, aged 19-55 years, includes laboratory staff, nurses, students and doctors. We obtained an average ratio of 1.42 which correlates well with the average of the other authors, especially with the normal ranges of Szasz [17], Haesen et al. [22], Jakobs [lo] and Korsten et al [ 111.
TABLE I SEX DIFFERENCES ‘ANILIDE METHODS) Author and year
IN THE y-GLUTAMYL TRANSFERASE ACCORDING TO THE NORMAL VALUES Test temp.
(EC 2.3.2.2) ACTIVITY @-NITROGIVEN BY VARIOUS AUTHORS
Activity in U/l corrected to 25’C. normal limits
Ratio Men/Women
*
(OC)
1969 1972 1972 1972 1972 1973 1974 1974 1975 1975 1976
Szasz [171 Haesen [ 221 Jacobs [lOI Rosslki [16] Rollason [151 Dingjan [231 Korsten [ill Kokot [211 Martin [14] szasz [ZOI Roche Cl91 20-60 years 1976 this paper:
25 25 25 (37) 25 25 (37) 25 (37) 25 25 median 25
Men
Women
4.5-24.8 6.0-21.0 4.5-22.0 -37.8 3.0-29.0 6.0-28.0 3.8-23.9 5.0-30.0 -15.1 6.0-28.0 24.0
3.2-13.5 5.0-16.0 4.0-13.0 -31.5 -
1.75 1.29 1.56 1.20
6.0-18.0 2.6-15.2 4.0-24.0 -10.7 4.0-18.0 17.0
1.42 1.57 1.25 1.41 1.54 1.41
5.2-22.2
4.7-14.5
1.42
Mean of sll ratios * Calculated as: Men (C upper A lower limit)/Women as quotient of upper limits or median values only.
1.44 (Z upper + lower limit) if available, otherwise
214
Consequently our use of the normal limits of 22.2 U/l for men and 14.5 U/l for women in calculating the index values is justified. c. Influence of alcohol consumption Various authors, for instance Rollason et al. [ 151, Rosalki and Rau [ 161 and Lamy et al. [l&13] have called attention to the increase of T-GT in alcoholism and hepatotoxic influences. y-GT increase can also be a consequence of drug induced dysfunction of the liver [21,11]. We therefore examined thoroughly for liver affections the clinical data of all those cases with evidently high y-GT values including those with chronic alcoholism. This resulted in a group of patients which we called “alcoholism and other liver disturbances” (Table II group VIII). The remaining patients showed no signs of alcoholism or any other injury of the liver function. We excluded all patients falling into group VIII from the main neurological groups in order to avoid any misinterpretation due to secondary influences. d. Enzyme activity of the neurological groups Fig. 1 represents the enzyme activities of the 142 samples expressed as U/l and as index values. In the relatively small groups under investigation, we see that the variability of the y-GT values is higher for women than for men (PA, VPE, TU, MS). Thus the 61 women of groups II-VII taken together show 28% increased values and 8% decreased, whereas the values for the 44 men are 14% and 4.5%, respectively. As sex differences are eliminated when we calculate the index values, their use enables us to compare directly the enzyme activities of the various groups with neurological diseases, The mean values of the groups and their 95% range are included in Table II. It is evident that discopathies and Parkinson’s disease cannot be differentiated from the normal reference group. Vascular brain affections, post-traumatic states with or without epilepsy, brain tumours and various other neurological diseases occasionally show higher values and consequently a slightly increased average. The deviations are, however, statistically insignificant. On the other hand, we find a considerable number of pathologi-
TABLE II r-GT: DIAGNOSTIC GROUPS AND NORMAL GROUP Index vafues as multiples of the sex refated upper normaI limit (men = 22.2; women = 14.5 U/f). Group
Mean index
Range of index (95% percentiles)
20
0.601
0.28-0.99
22 16 15 8 35 9
0.631 0.619 0.716 0.729 0.895 0.757
0.20-1.69 0.20-1.11 0.23-1.29 0.12-6.44 0.14-5.01 0.14-3.05
17
2.636
0.99-19.9
N
reference group
I
Normal
II III IV V VI VII
Discus hernias + discopathies Parkinson’s disease Vascular, post traumatic and epileptic brain affections Tumours of the CNS Multiple sclerosis Various other (mostIy peripheral nervous) nemologic deseases
Vi11 Chronic alcoholism and toxic or viral liver affections
215 PA
V,PJz
MS
OIV
A.L 0
Ii 0
.
I 0
.
0
&
80 :g lc0 lii
:B t: .O 0
;? ;I . 0
;a 0
10 0
. 0
Fig. 1. r-Glutamyl transferase activity (EC 2.3.2.2) of various neurological diseases (logarithmic ordinate). a, men; 0, women. Upper half: enzyme activity as U/l; lower half: enzyme activity as index value of the upper normal limit. Dotted line: the upper and lower limits of normal persons (no longer depending on the sex). N, normal controls, DH. discushernia, discopathy; PA, Parkinson’s disease; V + P + E. cerebrovascular + posttraumatic + epileptic affection; TU, tumours of the CNS; MS, multiple sclerosis; DIV. various other affections, A + L. alcoholism and other liver affections.
tally increased enzyme activities in multiple sclerosis. The deviation of the MS group from normal is significant, with P = 0.03 and 0.04 for T-test (lognormal) and Wilcoxon rang test, respectively. If we subdivide the MS patients into those developing bouts and those with chronic progression or in the inactive state, a remarkable but statistically insignificant difference is observed (Table III). However, the patients with chronic MS have a higher average age by ten years; experience shows that this group can be expected to be ill for a longer period and we therefore can con-
TABLE
III
COMPARISON OF THE SEX RELATED INDEX VALUES OF MS PATIENTS WITH ACUTE EXACERBATION AND WITH CHRONIC PROGRESSION OR DISABLED, INACTIVE STATES OF MULTIPLE SCLEROSIS MS subgroup *
Age (years)
N
Mean index
Range of index (95% percentile)
Cases with bouts Chronic cases
12-34-56 19-4267
20 14
0.106 1.158
0.20-2.47 0.20-5.32
* 1 case not classiflble
because of lack of sufficient
data.
216 TABLE IV COMPARISON OF THE y-GT-TEST WITH OTHER ANALYSES COMPUTING THE INDEX VALUES FOR ALL TESTS -
OF THE LIVER FUNCTION
AFTER
Criteria
y-GT (EC2.3.2.2)
GOT (EC2.fi.l.l)
GPT (EC2.6.1.2)
AP (EC3.1.3.1)
Bilirubin
Number of pairs
57
57
57
49
28
24 (42)
16 (28)
11 (19)
7 (14)
2 (7)
-
10 (18)
9 (16)
5 (10)
1 14)
Pathological values, total (over 1.0) (in %I Pathological vafues in coincidence with 7-GT (in %I Isolated pathological results, i.e. all other tests normal (in %) Correlation coefficient, r: (yGT versus other tests) * Significance against null * *
11 (19) -
4
1
1
0
(7)
(21
12)
(0)
0.428 0.001
0.429 0.001
0.309 0.03
0.015 None
* Calculated as logarithm of the index values because most populations show a log-normal distribution. ** According to Documenta Geigy, Wiss. Tabellen, 7th edn.. p. 61, Bask 1968.
elude that the degree of disturbance in liver function grows with the duration of the illness.
In 57 cases transaminase determinations (GOT, GPT) and y-GT determinations were carried out simultaneously, in 49 of them alkaline phosphatase as well. 28 values of the bilirubin content in the serum are also available. Table IV shows that the test which gives pathological values most frequently in our neurological patients is the y-GT test (42%), being the only pathological test in about half of the cases (19%). These latter cases include 2 epileptics with alcoholic anamnesis, 1 rhabdomyosarcoma with affection of the cerebellum, 1 cerebrovascular insult with diabetes mellitus and 7 mainly chronic MS patients. As can be expected, the correlation with the tran~mina~s is fairly good, and better than with the alkaline phosphatase. There is no relation to the bilirubin, however, the coefficient P being nearly zero. Discussion The comparison in Table IV of various enzymatic and chemical analyses confirms the well-known fact that all of these liver tests have their own importance in individual cases, although significant statistical correlations between the y-GT test and the tr~s~inases or the alkaline phosphatase do exist. We agree with some authors [10,15,16] that the T-GT test already reacts pathologically when other liver function tests are still normal. This seems to be true not only for alcoholics, for which it is a very sensitive indicator, but also for some neurological diseases, often connnected with a liver affection. By exclusion of all cases with definite toxic or viral liver disturb~ce and by grouping according to diagnosis we come to the following conclusions:
217
The groups with tumours, vascular, traumatic and epileptic brain affection, Parkinson’s disease and the discopathies show slightly higher values than the reference group, but in our study a real differentiation between these diseases is not possible. Their y-GT activities fall within the normal range and only some extreme values raise the average of the groups in question. The few diminished values are probably meaningless, since the y-GT is a cell bound enzyme with no primary reason for being in the serum. Excluding the alcoholics, the MS patients then remain the only diagnostic group of interest in our study. A very careful search of the hospital reports was made for signs of increased alcohol consumption but this did not seem to be the explanation for the increased y-GT values. It is evident, therefore, that about a third of the MS-patients show moderately elevated y-GT activities in serum, the liver disturbance being more pronounced in chronic MS patients than in those with a development in bouts. Thus, we conclude that the y-GT test is able to replace partially the sensitive but very unpleasant and therefore abandoned test for glycine availability. Pathological results in cases of multiple sclerosis are not quite as frequent with the new test as with the earlier one. However, this kinetic measurement, which is so simple and causes the patient no discomfort, offers a useful method for perceiving and following up a seriously disturbed liver function. References
9 10 11 12 13 14 15 16 17
Georgi. F. (1952) Arch. Psychiatr. Z. Neural. 187, 496-487 Vollgraff. G. (1967) Med. Diss. Bawl, and Psychiatr. Neural. Base1 154, 50-60 Rieder. H.P. (1956) Clin. Chim. Acta 1,481498 M6ller. H.R. (1955) Med. Diss. Base& and Confinia Neural. 15.250-265 Menkes. S. (1963) Med. Diss. Bawl, and Beihefte zur Alkoholfrage in der Schweiz 36 Karp, J. (1963) Med. Diss. Base1 Rieder, H.P. (1956) Z. Klin. Med. 154. 87-110 Colombo. J.P. (1974) Schriftenreihe Schweiz. Ges. Klin. Chem.. Heft 2. Chemieverlag Vogt-Schild AG. Solothurn CH Haralambie. G. (1976) Clin. Chim. Acta 72.363569 Jacobs, N.L.W. (1972) Clin. Chim. Acta 38.419434 Korsten. C.B.. Persijn. J.P. and van der Slik, W. (1974) Z. Klin. Chem. Klin. Biochem. 12. 116-120 Lamy. J.. Baglin. XC.. Aron, E. and Weill. J. (1975) Clin. Chim. Acta 60.97-101 Lamy. J., Baglin, M.C.. Feaant. J.P. and Weill, J. (1975) Clin. Cbim. Acta 60. 103-107 Martin Jennifer, V. and Gray. P.B. (1975) Clin. Chim. Acta 61, 99-101 Rollason, J.G., Pincherle, G. and Robinson, D. (1972) Clin. Chim. Acta 39. 75-80 Rosalki. S.B. and Rau. D. (1972) Clin. Chim. Acta 39.4147 Szasz, G. (1970) in Methoden der enzymatischen Analyse (Bergmeyer, H.U. ed.) 2nd edn.. PP. 733-
18 19 20 21 22 23
738. Verlag Chemie, Weinheim/Bergstrasse Ewen. Liliin, M. and Griffiths, J. (1973) Am. J. Clin. Pathol. 59, 2-9 Roche (1976) Neuer Firmenprospekt Hoffmann-La Roche & Cie AG. Base1 Szasz. G. (1974/75) Firmenanleitung Boehringer Mannheim GmbH (Monotest y-GT, No. 15885) Kokot, F. and Slezinski. Z. (1974) Z. Klin. Chem. Klin. Biochem. 12, 374-384 Haeaen. J.P., Berends, G.T. and Zondag, H.A. (1972) Clin. Chim. Acta 37,463-470 Dingian, P.G., Postma. T. and Stroes, J.A.P. (1973) Z. Klin. Chem. Klin. Biochem. 11. 167-171
Clinica Chimica Acta, 79 (1977) 211-217 @ Elsevier/North-Holland Biomedical Press
CCA 8781
THE ACTIVITY OF y-GLUTAMYL TRANSFERASE IN THE SERUM OF MULTIPLE SCLEROSIS AND OTHER NEUROLOGICAL DISEASES
H.P. RIEDER
*, HEIDI ZURFLUH
Neurologische
Universitiitsklinik, Forschungslaboratorium,
(Received
March 18th,
and SILVIA
JEGGE CH-4051 Base1 (Switzerland)
1977)
Summary
1. In the sera of 142 neurological patients, including 35 cases with multiple sclerosis (MS), and 20 normal controls the y-glutamyltransferase (y-GT) activity was determined. The result of this investigation was compared with the “combined hippuric acid test” formerly often used in MS patients. 2. The MS patients are the only group which significantly differs from the normal controls. There are also small differences between them and some of the other neurological patient groups. About one-third of the MS patients show moderately pathological serum activites. On the other hand, patients with a definite liver affection, especially chronic alcoholics, regularly show an even more important elevation of the values, which makes this test a sensitive tool for the screening of alcohol-induced liver intoxications. 3. Although the y-GT test in not quite as sensitive in indicating organic defects in MS patients, it seems to reflect a disturbed liver function in the same way as the more complicated “combined hippuric acid test”. It may therefore be used as a simple tool for finding and following up organic defects in MS patients.
Introduction
In 1952 Georgi and coworkers [l] found that there is a certain disturbance of liver function in patients with multiple sclerosis, particularly in the state of acute exacerbation or chronically active progression of the disease [2]. For this investigation they chose the hippuric acid test, which was often used at that time, particularly in its combined application as a test for glycine availability. This laborious test, which measures the detoxication of ingested benzoic acid by endogenous glycine, aims at measuring a specific function of the liver. * Address for correspondence: Basel. Switzerland.
Dr. H.P. Rieder,
Neurologische
Univ. Klinik. Socinstrasse
55. CH-4051
212
It is therefore obviously able to indicate a more subtle dysfunction than either the determiaation of bilirubin or the bromosuIfophth~ein-test, which were performed for comparison at that time [3]. However, we cannot expect the hippuric acid test to be diagnostically specific for a certain disease, since similar liver disturbances are found in schizophrenia [4], chronic alcoholism [5f and other neurofogieaI diseases [ 61 e+Moreover a significant temporary disturbance has also been demonstrated in the psychosis provoked by 0.5 g mescaline or 100-125 lg LSD [7], a fact worth remembering in these days of uncontrolled drug consumption. Since that time there have been many advances in liver diagnostics. As well as the tr~saminases, which have been known for a long time, ~-gIu~myItr~sferease in serum has been recognised as an especially good indicator of the degree of disturbance in liver function [8-l?‘]; its determination now belongs to the programme of the clinical chemical laboratory. On the other hand the hippuric acid test and its variants have fallen out of use, as they are both too expensive for the laboratory and disagreeable for the patient. We were therefore interested in finding out to what extent the liver-specific y_GT test could replace the test for glycine availability in the differential diagnosis of MS and other neurological diseases_ We are aware that some American authors [lS f have aIready touched on this question in 1973, but they neither specified the sex of the patients examined nor considered the important sex difference of the normal values. Their results may therefore be misleading.
The enzyme activity in the sera of the following patients was determined in immediately or after preservation at -20°C until the day of determination; a previous comparative study no change of activity was found after storage in this way. The patients are subdivided into the following groups (number of cases in parenthesis) MS: (35) multiple sclerosis TU: ( 8) brain or spinal tumour VPE: (15) vascular, posttraumatic and/or epileptic brain affection DH: (22) discus hernia and discopathy (16) Parkinson’s disease PA: DIV: ( 7) various other neurological diseases (14) alcoholism and other disturbed liver function AL: N: (20) healthy control persons for comparison For the assay of y-Gt activity the commercial test kits of Roche and Boehringer were used Cp-nitranilide-method with glycylglycine as co-substrate); measurement at 405 nm and 25°C. In about hdf of the cases the trsnsaminases * and alkaline phosphatase ** were determined at the same time and occasionlrlly also bilirubin *. In order to compare different tests, or groups of patients with different sex compositions, * %iochemica-tesE_com~~~tions%oehrmp?r,Mannkeim, ** Diignostica Merk. Darmstadt. G.F.R., kinetic test.
G.F.R.
213
we have used a special index (individual value/upper limit of the normal value of the corresponding sex) instead of the volume activity, i.e. the absolute concentration U/l. Thus the upper normal limit of the index equals 1.0 for both sexes and all methods. Results a. Reproducibility From 43 double assays during the whole investigation, we find a serial standard deviation of Sd = 0.57 U/l (V = 3.3%). The deviation from day to day of a control series with 39 determinations is 1.25 U/l (V = 8.7%). b. Normal values and limits Because of the well-known sex difference we must define different normal limits for men and women before computing the index values. In so doing we should first ask to what extent the normal values which we have found correspond with those in the literature, in order to be sure that their use in calculating the index is justified. Table I compares the data of various authors. It shows that men, contrary to some other suggestions [21], have on the average about 44% higher values than women. Neglecting the lowest and highest extreme values, most ratios from the groups under investigation fall into the range of 1.3-1.6. Our normal group, aged 19-55 years, includes laboratory staff, nurses, students and doctors. We obtained an average ratio of 1.42 which correlates well with the average of the other authors, especially with the normal ranges of Szasz [17], Haesen et al. [22], Jakobs [lo] and Korsten et al [ 111.
TABLE I SEX DIFFERENCES ‘ANILIDE METHODS) Author and year
IN THE y-GLUTAMYL TRANSFERASE ACCORDING TO THE NORMAL VALUES Test temp.
(EC 2.3.2.2) ACTIVITY @-NITROGIVEN BY VARIOUS AUTHORS
Activity in U/l corrected to 25’C. normal limits
Ratio Men/Women
*
(OC)
1969 1972 1972 1972 1972 1973 1974 1974 1975 1975 1976
Szasz [171 Haesen [ 221 Jacobs [lOI Rosslki [16] Rollason [151 Dingjan [231 Korsten [ill Kokot [211 Martin [14] szasz [ZOI Roche Cl91 20-60 years 1976 this paper:
25 25 25 (37) 25 25 (37) 25 (37) 25 25 median 25
Men
Women
4.5-24.8 6.0-21.0 4.5-22.0 -37.8 3.0-29.0 6.0-28.0 3.8-23.9 5.0-30.0 -15.1 6.0-28.0 24.0
3.2-13.5 5.0-16.0 4.0-13.0 -31.5 -
1.75 1.29 1.56 1.20
6.0-18.0 2.6-15.2 4.0-24.0 -10.7 4.0-18.0 17.0
1.42 1.57 1.25 1.41 1.54 1.41
5.2-22.2
4.7-14.5
1.42
Mean of sll ratios * Calculated as: Men (C upper A lower limit)/Women as quotient of upper limits or median values only.
1.44 (Z upper + lower limit) if available, otherwise
214
Consequently our use of the normal limits of 22.2 U/l for men and 14.5 U/l for women in calculating the index values is justified. c. Influence of alcohol consumption Various authors, for instance Rollason et al. [ 151, Rosalki and Rau [ 161 and Lamy et al. [l&13] have called attention to the increase of T-GT in alcoholism and hepatotoxic influences. y-GT increase can also be a consequence of drug induced dysfunction of the liver [21,11]. We therefore examined thoroughly for liver affections the clinical data of all those cases with evidently high y-GT values including those with chronic alcoholism. This resulted in a group of patients which we called “alcoholism and other liver disturbances” (Table II group VIII). The remaining patients showed no signs of alcoholism or any other injury of the liver function. We excluded all patients falling into group VIII from the main neurological groups in order to avoid any misinterpretation due to secondary influences. d. Enzyme activity of the neurological groups Fig. 1 represents the enzyme activities of the 142 samples expressed as U/l and as index values. In the relatively small groups under investigation, we see that the variability of the y-GT values is higher for women than for men (PA, VPE, TU, MS). Thus the 61 women of groups II-VII taken together show 28% increased values and 8% decreased, whereas the values for the 44 men are 14% and 4.5%, respectively. As sex differences are eliminated when we calculate the index values, their use enables us to compare directly the enzyme activities of the various groups with neurological diseases, The mean values of the groups and their 95% range are included in Table II. It is evident that discopathies and Parkinson’s disease cannot be differentiated from the normal reference group. Vascular brain affections, post-traumatic states with or without epilepsy, brain tumours and various other neurological diseases occasionally show higher values and consequently a slightly increased average. The deviations are, however, statistically insignificant. On the other hand, we find a considerable number of pathologi-
TABLE II r-GT: DIAGNOSTIC GROUPS AND NORMAL GROUP Index vafues as multiples of the sex refated upper normaI limit (men = 22.2; women = 14.5 U/f). Group
Mean index
Range of index (95% percentiles)
20
0.601
0.28-0.99
22 16 15 8 35 9
0.631 0.619 0.716 0.729 0.895 0.757
0.20-1.69 0.20-1.11 0.23-1.29 0.12-6.44 0.14-5.01 0.14-3.05
17
2.636
0.99-19.9
N
reference group
I
Normal
II III IV V VI VII
Discus hernias + discopathies Parkinson’s disease Vascular, post traumatic and epileptic brain affections Tumours of the CNS Multiple sclerosis Various other (mostIy peripheral nervous) nemologic deseases
Vi11 Chronic alcoholism and toxic or viral liver affections
215 PA
V,PJz
MS
OIV
A.L 0
Ii 0
.
I 0
.
0
&
80 :g lc0 lii
:B t: .O 0
;? ;I . 0
;a 0
10 0
. 0
Fig. 1. r-Glutamyl transferase activity (EC 2.3.2.2) of various neurological diseases (logarithmic ordinate). a, men; 0, women. Upper half: enzyme activity as U/l; lower half: enzyme activity as index value of the upper normal limit. Dotted line: the upper and lower limits of normal persons (no longer depending on the sex). N, normal controls, DH. discushernia, discopathy; PA, Parkinson’s disease; V + P + E. cerebrovascular + posttraumatic + epileptic affection; TU, tumours of the CNS; MS, multiple sclerosis; DIV. various other affections, A + L. alcoholism and other liver affections.
tally increased enzyme activities in multiple sclerosis. The deviation of the MS group from normal is significant, with P = 0.03 and 0.04 for T-test (lognormal) and Wilcoxon rang test, respectively. If we subdivide the MS patients into those developing bouts and those with chronic progression or in the inactive state, a remarkable but statistically insignificant difference is observed (Table III). However, the patients with chronic MS have a higher average age by ten years; experience shows that this group can be expected to be ill for a longer period and we therefore can con-
TABLE
III
COMPARISON OF THE SEX RELATED INDEX VALUES OF MS PATIENTS WITH ACUTE EXACERBATION AND WITH CHRONIC PROGRESSION OR DISABLED, INACTIVE STATES OF MULTIPLE SCLEROSIS MS subgroup *
Age (years)
N
Mean index
Range of index (95% percentile)
Cases with bouts Chronic cases
12-34-56 19-4267
20 14
0.106 1.158
0.20-2.47 0.20-5.32
* 1 case not classiflble
because of lack of sufficient
data.
216 TABLE IV COMPARISON OF THE y-GT-TEST WITH OTHER ANALYSES COMPUTING THE INDEX VALUES FOR ALL TESTS -
OF THE LIVER FUNCTION
AFTER
Criteria
y-GT (EC2.3.2.2)
GOT (EC2.fi.l.l)
GPT (EC2.6.1.2)
AP (EC3.1.3.1)
Bilirubin
Number of pairs
57
57
57
49
28
24 (42)
16 (28)
11 (19)
7 (14)
2 (7)
-
10 (18)
9 (16)
5 (10)
1 14)
Pathological values, total (over 1.0) (in %I Pathological vafues in coincidence with 7-GT (in %I Isolated pathological results, i.e. all other tests normal (in %) Correlation coefficient, r: (yGT versus other tests) * Significance against null * *
11 (19) -
4
1
1
0
(7)
(21
12)
(0)
0.428 0.001
0.429 0.001
0.309 0.03
0.015 None
* Calculated as logarithm of the index values because most populations show a log-normal distribution. ** According to Documenta Geigy, Wiss. Tabellen, 7th edn.. p. 61, Bask 1968.
elude that the degree of disturbance in liver function grows with the duration of the illness.
In 57 cases transaminase determinations (GOT, GPT) and y-GT determinations were carried out simultaneously, in 49 of them alkaline phosphatase as well. 28 values of the bilirubin content in the serum are also available. Table IV shows that the test which gives pathological values most frequently in our neurological patients is the y-GT test (42%), being the only pathological test in about half of the cases (19%). These latter cases include 2 epileptics with alcoholic anamnesis, 1 rhabdomyosarcoma with affection of the cerebellum, 1 cerebrovascular insult with diabetes mellitus and 7 mainly chronic MS patients. As can be expected, the correlation with the tran~mina~s is fairly good, and better than with the alkaline phosphatase. There is no relation to the bilirubin, however, the coefficient P being nearly zero. Discussion The comparison in Table IV of various enzymatic and chemical analyses confirms the well-known fact that all of these liver tests have their own importance in individual cases, although significant statistical correlations between the y-GT test and the tr~s~inases or the alkaline phosphatase do exist. We agree with some authors [10,15,16] that the T-GT test already reacts pathologically when other liver function tests are still normal. This seems to be true not only for alcoholics, for which it is a very sensitive indicator, but also for some neurological diseases, often connnected with a liver affection. By exclusion of all cases with definite toxic or viral liver disturb~ce and by grouping according to diagnosis we come to the following conclusions:
217
The groups with tumours, vascular, traumatic and epileptic brain affection, Parkinson’s disease and the discopathies show slightly higher values than the reference group, but in our study a real differentiation between these diseases is not possible. Their y-GT activities fall within the normal range and only some extreme values raise the average of the groups in question. The few diminished values are probably meaningless, since the y-GT is a cell bound enzyme with no primary reason for being in the serum. Excluding the alcoholics, the MS patients then remain the only diagnostic group of interest in our study. A very careful search of the hospital reports was made for signs of increased alcohol consumption but this did not seem to be the explanation for the increased y-GT values. It is evident, therefore, that about a third of the MS-patients show moderately elevated y-GT activities in serum, the liver disturbance being more pronounced in chronic MS patients than in those with a development in bouts. Thus, we conclude that the y-GT test is able to replace partially the sensitive but very unpleasant and therefore abandoned test for glycine availability. Pathological results in cases of multiple sclerosis are not quite as frequent with the new test as with the earlier one. However, this kinetic measurement, which is so simple and causes the patient no discomfort, offers a useful method for perceiving and following up a seriously disturbed liver function. References
9 10 11 12 13 14 15 16 17
Georgi. F. (1952) Arch. Psychiatr. Z. Neural. 187, 496-487 Vollgraff. G. (1967) Med. Diss. Bawl, and Psychiatr. Neural. Base1 154, 50-60 Rieder. H.P. (1956) Clin. Chim. Acta 1,481498 M6ller. H.R. (1955) Med. Diss. Base& and Confinia Neural. 15.250-265 Menkes. S. (1963) Med. Diss. Bawl, and Beihefte zur Alkoholfrage in der Schweiz 36 Karp, J. (1963) Med. Diss. Base1 Rieder, H.P. (1956) Z. Klin. Med. 154. 87-110 Colombo. J.P. (1974) Schriftenreihe Schweiz. Ges. Klin. Chem.. Heft 2. Chemieverlag Vogt-Schild AG. Solothurn CH Haralambie. G. (1976) Clin. Chim. Acta 72.363569 Jacobs, N.L.W. (1972) Clin. Chim. Acta 38.419434 Korsten. C.B.. Persijn. J.P. and van der Slik, W. (1974) Z. Klin. Chem. Klin. Biochem. 12. 116-120 Lamy. J.. Baglin. XC.. Aron, E. and Weill. J. (1975) Clin. Chim. Acta 60.97-101 Lamy. J., Baglin, M.C.. Feaant. J.P. and Weill, J. (1975) Clin. Cbim. Acta 60. 103-107 Martin Jennifer, V. and Gray. P.B. (1975) Clin. Chim. Acta 61, 99-101 Rollason, J.G., Pincherle, G. and Robinson, D. (1972) Clin. Chim. Acta 39. 75-80 Rosalki. S.B. and Rau. D. (1972) Clin. Chim. Acta 39.4147 Szasz, G. (1970) in Methoden der enzymatischen Analyse (Bergmeyer, H.U. ed.) 2nd edn.. PP. 733-
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738. Verlag Chemie, Weinheim/Bergstrasse Ewen. Liliin, M. and Griffiths, J. (1973) Am. J. Clin. Pathol. 59, 2-9 Roche (1976) Neuer Firmenprospekt Hoffmann-La Roche & Cie AG. Base1 Szasz. G. (1974/75) Firmenanleitung Boehringer Mannheim GmbH (Monotest y-GT, No. 15885) Kokot, F. and Slezinski. Z. (1974) Z. Klin. Chem. Klin. Biochem. 12, 374-384 Haeaen. J.P., Berends, G.T. and Zondag, H.A. (1972) Clin. Chim. Acta 37,463-470 Dingian, P.G., Postma. T. and Stroes, J.A.P. (1973) Z. Klin. Chem. Klin. Biochem. 11. 167-171