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Outcomes and treatment of obstetrical antiphospholipid syndrome in women with low antiphospholipid antibody levels
Journal of Reproductive Immunology 94 (2012) 222–226
Contents lists available at SciVerse ScienceDirect
Journal of Reproductive Immunology journal homepage: www.elsevier.com/locate/jreprimm
Outcomes and treatment of obstetrical antiphospholipid syndrome in women with low antiphospholipid antibody levels Arsene Mekinian a,∗ , Priscille Loire-Berson b , Pascale Nicaise-Roland c , Eric Lachassinne d , Jerome Stirnemann a , Marie-Claire Boffa e , Sylvie Chollet-Martin c , Lionel Carbillon b , Olivier Fain a a b c d e
Service de Médecine Interne, Université Paris 13, AP-HP, Hôpital Jean Verdier, 93140 Bondy, France Service de Gynécologie-Obstétrique, Université Paris 13, AP-HP, Hôpital Jean Verdier, 93140 Bondy, France Unité Fonctionnelle d’Immunologie “Autoimmunité et Hypersensibilités’, AP-HP, Hôpital Bichat-Claude Bernard, 75019 Paris, France Service de Néonatologie et Pédiatrie, Université Paris 13, AP-HP, Hôpital Jean Verdier, 93140 Bondy, France Service d’Hématologie Biologique, Université Paris 13, AP-HP, Hôpital Jean Verdier, 93140 Bondy, France
a r t i c l e
i n f o
Article history: Received 26 September 2011 Received in revised form 22 November 2011 Accepted 2 February 2012
Keywords: Antiphospholipid syndrome Antiphospholipid level Obstetrical events
a b s t r a c t Our objective was to determine whether there is a relationship between low antiphospholipid (aPL) antibody levels and the obstetrical complications of antiphospholipid syndrome (APS) and to analyze the impact of conventional APS treatment in patients with low aPL levels. To this end, we retrospectively reviewed the files of all patients referred to our unit (2003–2010) for unexplained pregnancy morbidity, with an aPL test result. We compared patients with APS confirmed by Sapporo criteria (Group 1) with patients with APS-like obstetrical complications with an aPL titer below the intermediate titer (Group 2). Overall, 57 patients were included (25 in Group 1; 32 in Group 2). Obstetrical events were recurrent spontaneous abortion <10th week of gestation (n = 9 patients in Group 1; n = 13 patients in Group 2), fetal death (n = 11 and 16, respectively), preeclampsia (n = 5 in Group 1; n = 6 in Group 2). The total number of obstetrical events per patient was very similar before APS treatment (3 [1–8] in Group 1; 3 [1–6] in Group 2) and decreased significantly after APS treatment to 0 [0–2] and 0 [0–2], respectively (p < 0.05). The incidence of premature births and the characteristics of neonates were similar in the two groups. In this study, treatment of patients with low aPL levels and APS-like obstetrical events was associated with outcomes similar to those found in otherwise normal women with recurrent miscarriage or other adverse events. However, properly designed treatment trials would be required to prove the benefit of such treatments. © 2012 Elsevier Ireland Ltd. All rights reserved.
Introduction Antiphospholipid syndrome (APS) is an autoimmune disease characterized by thrombotic and/or obstetrical
∗ Corresponding author at: Service de Médecine Interne Université Paris 13, AP-HP, Hôpital Jean Verdier, Avenue 14 Juillet, 93140 Bondy, France. Tel.: +33 148026047; fax: +33 148026361. E-mail addresses: [email protected], [email protected] (A. Mekinian). 0165-0378/$ – see front matter © 2012 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.jri.2012.02.004
complications caused by antiphospholipid antibodies (aPL) (Wilson et al., 1999; Miyakis et al., 2006). Patients tend to present either thrombotic or obstetrical complications, but rarely both (Kist et al., 2008). During the course of the disease aPL levels may vary and even become undetectable (Roubey, 1994). Current revised Sapporo classification criteria consider a diagnosis of APS only when aPL levels are moderate or high, but low antibody levels have been reported in patients with thrombotic complications (Amaral et al., 2010; Dunn et al., 2005). Cases of
A. Mekinian et al. / Journal of Reproductive Immunology 94 (2012) 222–226
recurrent early miscarriage and fetal death with intermediate or low aPL levels not meeting the revised Sapporo criteria are increasingly considered as APS in the USA (Branch et al., 2010a,b). Triple positivity (the presence of tree different aPLs) is associated with a significantly higher rate of pregnancy loss in obstetrical APS (Ruffatti et al., 2009). However, a single positive aPL test is more common in purely obstetrical APS than in thrombotic or mixed APS (Boffa et al., 2009). It is important not to overlook a diagnosis of APS in patients with obstetrical complications as rapid intervention with conventional treatments can much improve pregnancy outcomes (Tuthil and Khamashta, 2009). However, moderate-to-high aPL levels remain the recommended criterion for APS diagnosis even though the APS diagnostic threshold may well prove to be lower during pregnancy (Branch et al., 2010a,b). The aim of this retrospective study was therefore to assess whether the presence of low-titer aPL might be associated with APS-like obstetrical events and to analyze the impact of conventional treatment with aspirin and/or low molecular-weight heparin (LMWH) in patients with low-titer aPL levels. Patients with low antibody levels were compared with a group of patients with confirmed obstetrical APS. Patients and methods Patients We retrospectively reviewed all patients with pregnancy morbidity who had undergone an aPL test in our university hospital between 2003 and 2010. aPLs were tested in the presence of poor obstetrical outcome and in the absence of obvious etiology. Morbidity was given by the Sapporo criteria: (1) More than three unexplained spontaneous abortions before the 10th week of gestation, (2) One or more fetal deaths at or beyond the 10th week, (3) At least one premature delivery due to severe preeclampsia or placental insufficiency. Other obstetrical events analyzed were intrauterine growth restriction (IUGR), and placental abruption. All women were tested for the presence of lupus anticoagulant (LA), IgG/IgM anticardiolipin (ACL) antibodies, and IgG/IgM anti-2 glycoprotein-I (2 GPI) antibodies, as well as for risk factors for thrombophilia (proteins C and S, antithrombin III, homocysteine, mutations of Factor V (Leiden) and prothrombin G20210A, and increased resistance to activated protein C (RAPC)). Inclusion criteria were: (1) Pregnancy morbidity according to Sapporo criteria in the absence of clinical and/or laboratory data consistent with other systemic autoimmune diseases, (2) More than one previous untreated pregnancy and more than one APS regimen-treated pregnancy. Patients with LA were excluded from the study in order to be able to assess the significance of low aPL levels (in patients from both Group 1 and Group 2, as defined in the next
223
paragraph). As recommended, aPL persistence was confirmed in all patients (Miyakis et al., 2006). Patients were divided into two groups: Group 1: patients with obstetrical APS with clinical and laboratory features in accordance with Sapporo criteria (Miyakis et al., 2006); Group 2: patients with obstetrical events consistent with clinical APS according to Sapporo criteria, but with an aPL level below an intermediate cut-off level. A control group of patients with obstetrical APS-like untreated pregnancies, but without aPL was also considered. Antibody assays All aPL determinations were performed in our university laboratory (UF Autoimmunité et Hypersensibilité, Hôpital Bichat-Claude Bernard). Screening for LA was based on dilute Russell’s viper venom time (DRVVT) and dilute activated partial thromboplastin time (DAPTT). ACL and anti-2 GPI antibodies were determined using commercial enzyme-linked immunoabsorbent assays (INOVA Diagnostics, San Diego, CA, USA). Cut-off values for intermediate titers (99th percentile) were 20 U/ml (GPL/MPL units) for ACL and 15 IU/ml for IgG and IgM anti-2 GPI. The aPL titer was low if included between the 90th and 99th percentile for either antibody. In a control group of 70 women without any obstetrical morbidity, low-titer aPL was present in 2.8% in our university laboratory. Treatment and outcomes Antiphospholipid syndrome treatment consisted of low-dose aspirin (100 mg/day) with or without LMWH (40 mg enoxaparin once daily). Neonatal outcome was assessed by the following: delivery mode, weeks of gestational age at delivery, birth weight, height and cranial circumference, 1- and 5-min Apgar score, and neonatal complications. Statistical analysis Quantitative data were expressed as medians with ranges and qualitative data as frequencies and percentages. Fisher’s exact test was used to compare qualitative variables and the Mann–Whitney U test or Wilcoxon’s test, as appropriate, to compare continuous variables. We used GraphPad Prism software (version 5.1; 2007). The significance level was set at p < 0.05. Results Patient characteristics A total of 57 patients met our inclusion criteria (median age 36 years; range, 27–45). Group 1 (confirmed APS) comprised 25 patients (median age 38 years, range, 27–45); 13 Caucasian (52%). Group 2 (APS-like obstetrical events and
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A. Mekinian et al. / Journal of Reproductive Immunology 94 (2012) 222–226
Table 1 Patient’s characteristics in untreated pregnancies. Confirmed APS (n = 25)
Low aPL level (n = 32)
aPL-negative patients (n = 21)
Patient characteristics Age (years) BMI (kg/m2 ) Tobacco use Hypertension/diabetes mellitus Thrombosis
38 (27–49) 26 (17–34) 2 (8) 3 (12) 2 (8)
34 (23–45) 23 (18–34) 4 (13) 3 (9) 5 (16)
Type of obstetrical event Three or more abortions <10th week of gestation Fetal death (≥1) Preeclampsia/eclampsia <34 weeks Placental abruption IUGR Total obstetrical events/patient
9 (36) 11 (44) 5 (20) 3 (12) 9 (36) 3 (1–8)
13 (41) 16 (50) 6 (19) 3 (9) 7 (22) 3 (1–6)
6 (29) 9 (42) 5 (29) 0 0* 3 (1–6)
APS laboratory data ACL IgG (number with frequency of positive values) ACL IgM Anti-2 GP1 IgG Anti-2 GP1 IgM
18 (72) 6 (24) 6 (24) 1 (4)
16 (50) 14 (44) 4 (13) 6 (19)
– – – –
Thrombophilia Protein S (%) Protein C (%) Antithrombin III (%) RAPC Homocysteine (mol/l) Factor V Leiden Prothrombin G20210A mutation
63 (25–91) 100 (80–130) 100 (77–123) 2.2 (2–2.3) 10 (6–47) 0 0
63 (30–95) 97 (64–160) 100 (10–110) 2 (1.5–2.5) 6 (4–14) 0 0
30 (24–45) 22 (17–41) 0 1 (5) 0
75 (55–100) 100 (80–100) 100 (77–100) 2.3 (2.2–2.7) 10 (7–10) 2 (10) 2 (10)
BMI: body mass index; IUGR: intrauterine growth restriction; APS: antiphospholipid syndrome; ACL: anticardiolipin; anti-2 GP1: anti-2 glycoprotein-I; RAPC: resistance to activated protein C. Values are medians with ranges in brackets or numbers with percentages in parentheses. * p < 0.05.
low-titer aPL) comprised 32 patients (median age 34 years, range, 23–45); 18 Caucasian (56%). Pretreatment clinical and laboratory data (aPL and thrombophilia) are given in Table 1 for both groups of patients. No difference between the two groups was noted concerning the number of patients with different obstetrical events (Table 1). Screening for APS was performed before pregnancy in 16/25 Group 1 patients and 17/32 Group 2 patients, and during pregnancy in all other patients. The total number of obstetrical events per patient was highly similar in both groups (3 [1–8] in Group 1; 3 [1–6] in Group 2). A group of 21 patients with obstetrical events, but without detectable aPL was analyzed and had a similar number of obstetrical events (Table 1). Antiphospholipid isotype frequencies were similar in the two groups and persisted with the same isotype and levels in most of the patients at the second determination at 12 weeks. At the second aPL determination, aPL isotype changed in one case in each group (ACL G versus anti-2 GPI G and ACL IgG versus ACL IgM); and anti-2 GPI G disappeared in three cases (n = 1 in Group 1 and n = 2 in Group 2; in these 3 patients associated ACL G persisted at the second determination). As ACL IgG was the predominant isotype in Group 1, only ACL IgG and not ACL IgM levels were compared between groups. The ACL IgG level was significantly higher in Group 1 than in Group 2 (22 [0–344] vs. 9 [0–20] U/ml; p < 0.0001). Risk factors for thrombophilia were similar in the two groups. No mutations of Factor V (Leiden) or prothrombin G20210A were detected.
Pregnancy and neonatal outcomes on APS treatment Median follow-up was 8 years (range, 4–16). The APS treatment regimen did not differ statistically between the groups. Treatment was introduced as from 12 weeks (range, 4–27) of pregnancy in Group 1 and 10 weeks (range, 5–25) in Group 2. Aspirin plus LMWH was administered in 21 (84%) cases of Group 1 and 27 (84%) cases of Group 2, LMWH alone in 2 cases each and aspirin alone in 2 and 3 cases, respectively (8% and 9%). No treatment was administered in the control group of patients without aPL. Outcomes in the patients treated are shown in Table 2. The total number of obstetrical events per patient decreased significantly in both groups after treatment to reach an identical median value (from 3 [1–8] to 0 [0–2] in Group 1 (p < 0.05) and from 3 [1–6] to 0 [0–2] in Group 2 [p < 0.05]). After treatment, the incidence of premature births, the proportion of cesarean sections, and the characteristics of neonates were similar in the two groups. Only two neonatal complications were noted in each group (neonatal infections and respiratory distress syndrome in two cases, respectively). No cases of thrombosis or neonatal lupus were reported. Discussion Our study has revealed, to our knowledge for the first time, that pregnancy outcomes in untreated patients with APS-like obstetrical events and low aPL levels are poor and
A. Mekinian et al. / Journal of Reproductive Immunology 94 (2012) 222–226
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Table 2 Patient’s pregnancy outcome and neonate characteristics under treatment during pregnancy. Confirmed APS(n = 25)
Low aPL level(n = 32)
0 0 0 0 3 (12) 3 (12) 0 (0–2) 1 (3) 4 (16)
0 2 (6) 1 (3) 0 1 (3) 4 (13) 0 (0–2) 0 4 (13)
2 (8) 21 (84)
3 (9) 27 (84)
Delivery Spontaneous vaginal delivery Cesarean section Term (weeks) Term <37 weeks
17 (68) 8 (32) 38 (29–40) 9 (36)
21 (66) 14 (44) 38 (24–41) 10 (31)
Characteristics of neonates Female Weight (g) Weight <2500 g Height (cm) Cranial circumference (cm) Apgar 1/5 min Neonatal complications
14 (56) 3100 (1150–3770) 6 (24) 49 (40–52) 35 (25–37) 10 (3–10)/10 (5–10) 2 (8)
17 (53) 3250 (510–4540) 4 (13) 49 (40–54) 35 (29–37) 10 (1–10)/10 (3–10) 2 (6)
Type of obstetrical event Three or more abortions <10th week of gestation Fetal death (≥1) Preeclampsia/eclampsia <34 weeks Placental abruption IUGR Premature delivery Total obstetrical events/patient Thrombosis during pregnancy Infections during pregnancy Treatments during pregnancy Aspirin alone (100 mg/day) Aspirin with LMWH
IUGR: intrauterine growth restriction. Values are medians with ranges in brackets or numbers with percentages in parentheses.
similar to those in obstetrical patients with confirmed APS. Conventional APS treatment substantially improved pregnancy and neonatal outcomes in both groups of patients. Antiphospholipid syndrome is usually diagnosed using clinical and laboratory Sapporo criteria. However, the aPL level that is associated with a clinical risk has not been established in practice. The threshold used in the Sapporo criteria is a moderate-to-high aPL level even though thrombotic and obstetrical complications have been reported in patients with low aPL levels (Roubey, 1994; Amaral et al., 2010; Reznikoff-Etievant et al., 1999). We here have substantiated a relationship between low aPL levels and obstetrical APS and confirmed our previous data that obstetrical APS tends to be associated with a single positive aPL test, and thus possibly represents a less active immunological disease than thrombotic APS (Boffa et al., 2009). Usually IgG antibodies are thought to correlate better with thrombosis than IgM antibodies and predominant single aPL positivity is characteristic of obstetrical APS (Boffa et al., 2009; De Laat et al., 2009). Pregnancy is a hypercoagulable state and inherited or acquired thrombophilia factors could be associated with adverse outcomes (Kupferminc, 2003). Few studies have evaluated the presence of additional prothrombotic factors in patients with APS, and their results are conflicting (Kist et al., 2008; Kupferminc, 2003). In our study, thrombophilia factors were similar between the two groups, with normal median values, and could thus not account for the adverse pregnancy outcomes in patients with low aPL levels. In line with the results of published studies, conventional APS treatment much improved pregnancy outcomes
(type of obstetrical event and total number of events per patient) in patients with confirmed APS. However, treatment also improved outcomes in patients with low aPL levels. Median term and birth weight, height and cranial circumference were normal in both groups after treatment. Only two neonatal complications were noted after treatment in each group. The limitations of our study were first its retrospective design. Similar obstetrical events were noted in patients with APS, low-titer patients and the control group before treatment; even the absence of treatment in the control group did not allow the comparison of pregnancy outcome after treatment. We compared morbidity in low versus moderate-to-high titer aPL groups, but small patient numbers ruled out comparisons relative to the type of obstetrical event and type of aPL, and also ruled out a comparison between treatment by aspirin alone and by aspirin plus LMWH. Furthermore, we did not assess the relationship of low-titer aPL outcomes with LA, even though LA tends to be associated with thrombosis and more adverse pregnancy outcomes. On the other hand, a strength of our study was its consistency. Treatment was identical irrespective of aPL titer; a single laboratory performed all aPL determinations and the prevalence of low-titer aPL was only 2.8% in the same laboratory. In conclusion, in our study patients with low aPL levels have similar outcomes, in particular with respect to obstetrical events, as patients who meet Sapporo criteria for APS diagnosis. In this study treatment of patients with low aPL levels and APS-like obstetrical events was associated with outcomes similar to those found in otherwise normal women with recurrent miscarriage or other adverse
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events. However, properly designed treatment trials would be required to prove the benefit of such treatments. Conflicts of interest None. Funding source Department funds. Author’s contributions All authors were involved in drafting the article. O. Fain had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of data analysis. Study conception and design were done by AM and OF. AM, PLB, JS, PNR, EL, MCB, SCM, LC and OF have done the data acquisition. Analysis and interpretation of data were performed by AM and OF. References Amaral, M., Favas, C., Alves, J.D., 2010. Persistency of low levels of anticardiolipin and anti-beta2 glycoprotein 1 in thrombosis. Eur. J. Intern. Med. 21, 101–103. Boffa, M.C., Boinot, C., De Carolis, S., Rovere-Querini, P., Aurousseau, M.H., Allegri, F., et al., 2009. Laboratory criteria of the obstetrical antiphospholipid syndrome. Data from a multicentric prospective European women cohort. Thromb. Haemost. 102, 25–28.
Branch, D.W., Silver, R.M., Porter, T.F., 2010a. Obstetrical antiphospholipid syndrome: current uncertainties should guide our way. Lupus 19, 446–452. Branch, D.W., Gibson, M., Silver, R.M., 2010b. Clinical practice. Recurrent miscarriage. N. Engl. J. Med. 363, 1740–1747. De Laat, B., Pengo, V., Pafinger, I., Musial, J., Voskuyl, A.E., Bultink, E.M., et al., 2009. The association between circulating antibodies against domain I of beta2-glycoprotein I and thrombosis: an international multicenter study. J. Thromb. Haemost. 7, 1767–1773. Dunn, A.S., Kaboli, P., Halfdanarson, T., Chan, H., Hubert, R., Rosen, S., et al., 2005. Do patients followed in anticoagulation clinics for antiphospholipid syndrome meet criteria for the disorder? Thromb. Haemost. 94, 548–554. Kist, W.J., Janssen, N.G., Kalk, J.J., Hague, W.M., Dekker, G.A., de Vries, J.I., 2008. Thrombophilias and adverse pregnancy outcome – a confounded problem! Thromb. Haemost. 99, 77–85. Kupferminc, M., 2003. Thrombophilia and pregnancy. Reprod. Biol. Endocrinol. 14, 111. Miyakis, S., Lockshin, M.D., Atsumi, T., Branch, D.W., Brey, R.L., Cervera, R., et al., 2006. International consensus statement on an update of the classification criteria for definite antiphospholipid syndrome (APS). J. Thromb. Haemost. 4, 295–306. Reznikoff-Etievant, M.F., Cayol, V., Zou, G.M., Abuaf, N., Robert, A., Johanet, C., et al., 1999. Habitual abortions in 678 healthy patients: investigation and prevention. Hum. Reprod. 14, 2106–2109. Roubey, R.A., 1994. Autoantibodies to phospholipids-binding plasma proteins: a new view of lupus anticoagulants and other antiphospholipid antibodies. Blood 84, 2854–2867. Ruffatti, A., Tonello, M., Cavazzana, A., Bagatella, P., Pengo, V., 2009. Laboratory classification categories and pregnancy outcome in patients with primary antiphospholipid syndrome prescribed antithrombotic therapy. Thromb. Res. 123, 482–487. Tuthil, J.I., Khamashta, M.A., 2009. Management of antiphospholipid syndrome. J. Autoimmun. 33, 92–98. Wilson, W.A., Gharavi, A.E., Koike, T., Lockshin, M.D., Branch, D.W., Piette, J.C., et al., 1999. International consensus statement on preliminary classification criteria for definite antiphospholipid syndrome: report of an international workshop. Arthritis Rheum. 42, 1309–1311.
Contents lists available at SciVerse ScienceDirect
Journal of Reproductive Immunology journal homepage: www.elsevier.com/locate/jreprimm
Outcomes and treatment of obstetrical antiphospholipid syndrome in women with low antiphospholipid antibody levels Arsene Mekinian a,∗ , Priscille Loire-Berson b , Pascale Nicaise-Roland c , Eric Lachassinne d , Jerome Stirnemann a , Marie-Claire Boffa e , Sylvie Chollet-Martin c , Lionel Carbillon b , Olivier Fain a a b c d e
Service de Médecine Interne, Université Paris 13, AP-HP, Hôpital Jean Verdier, 93140 Bondy, France Service de Gynécologie-Obstétrique, Université Paris 13, AP-HP, Hôpital Jean Verdier, 93140 Bondy, France Unité Fonctionnelle d’Immunologie “Autoimmunité et Hypersensibilités’, AP-HP, Hôpital Bichat-Claude Bernard, 75019 Paris, France Service de Néonatologie et Pédiatrie, Université Paris 13, AP-HP, Hôpital Jean Verdier, 93140 Bondy, France Service d’Hématologie Biologique, Université Paris 13, AP-HP, Hôpital Jean Verdier, 93140 Bondy, France
a r t i c l e
i n f o
Article history: Received 26 September 2011 Received in revised form 22 November 2011 Accepted 2 February 2012
Keywords: Antiphospholipid syndrome Antiphospholipid level Obstetrical events
a b s t r a c t Our objective was to determine whether there is a relationship between low antiphospholipid (aPL) antibody levels and the obstetrical complications of antiphospholipid syndrome (APS) and to analyze the impact of conventional APS treatment in patients with low aPL levels. To this end, we retrospectively reviewed the files of all patients referred to our unit (2003–2010) for unexplained pregnancy morbidity, with an aPL test result. We compared patients with APS confirmed by Sapporo criteria (Group 1) with patients with APS-like obstetrical complications with an aPL titer below the intermediate titer (Group 2). Overall, 57 patients were included (25 in Group 1; 32 in Group 2). Obstetrical events were recurrent spontaneous abortion <10th week of gestation (n = 9 patients in Group 1; n = 13 patients in Group 2), fetal death (n = 11 and 16, respectively), preeclampsia (n = 5 in Group 1; n = 6 in Group 2). The total number of obstetrical events per patient was very similar before APS treatment (3 [1–8] in Group 1; 3 [1–6] in Group 2) and decreased significantly after APS treatment to 0 [0–2] and 0 [0–2], respectively (p < 0.05). The incidence of premature births and the characteristics of neonates were similar in the two groups. In this study, treatment of patients with low aPL levels and APS-like obstetrical events was associated with outcomes similar to those found in otherwise normal women with recurrent miscarriage or other adverse events. However, properly designed treatment trials would be required to prove the benefit of such treatments. © 2012 Elsevier Ireland Ltd. All rights reserved.
Introduction Antiphospholipid syndrome (APS) is an autoimmune disease characterized by thrombotic and/or obstetrical
∗ Corresponding author at: Service de Médecine Interne Université Paris 13, AP-HP, Hôpital Jean Verdier, Avenue 14 Juillet, 93140 Bondy, France. Tel.: +33 148026047; fax: +33 148026361. E-mail addresses: [email protected], [email protected] (A. Mekinian). 0165-0378/$ – see front matter © 2012 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.jri.2012.02.004
complications caused by antiphospholipid antibodies (aPL) (Wilson et al., 1999; Miyakis et al., 2006). Patients tend to present either thrombotic or obstetrical complications, but rarely both (Kist et al., 2008). During the course of the disease aPL levels may vary and even become undetectable (Roubey, 1994). Current revised Sapporo classification criteria consider a diagnosis of APS only when aPL levels are moderate or high, but low antibody levels have been reported in patients with thrombotic complications (Amaral et al., 2010; Dunn et al., 2005). Cases of
A. Mekinian et al. / Journal of Reproductive Immunology 94 (2012) 222–226
recurrent early miscarriage and fetal death with intermediate or low aPL levels not meeting the revised Sapporo criteria are increasingly considered as APS in the USA (Branch et al., 2010a,b). Triple positivity (the presence of tree different aPLs) is associated with a significantly higher rate of pregnancy loss in obstetrical APS (Ruffatti et al., 2009). However, a single positive aPL test is more common in purely obstetrical APS than in thrombotic or mixed APS (Boffa et al., 2009). It is important not to overlook a diagnosis of APS in patients with obstetrical complications as rapid intervention with conventional treatments can much improve pregnancy outcomes (Tuthil and Khamashta, 2009). However, moderate-to-high aPL levels remain the recommended criterion for APS diagnosis even though the APS diagnostic threshold may well prove to be lower during pregnancy (Branch et al., 2010a,b). The aim of this retrospective study was therefore to assess whether the presence of low-titer aPL might be associated with APS-like obstetrical events and to analyze the impact of conventional treatment with aspirin and/or low molecular-weight heparin (LMWH) in patients with low-titer aPL levels. Patients with low antibody levels were compared with a group of patients with confirmed obstetrical APS. Patients and methods Patients We retrospectively reviewed all patients with pregnancy morbidity who had undergone an aPL test in our university hospital between 2003 and 2010. aPLs were tested in the presence of poor obstetrical outcome and in the absence of obvious etiology. Morbidity was given by the Sapporo criteria: (1) More than three unexplained spontaneous abortions before the 10th week of gestation, (2) One or more fetal deaths at or beyond the 10th week, (3) At least one premature delivery due to severe preeclampsia or placental insufficiency. Other obstetrical events analyzed were intrauterine growth restriction (IUGR), and placental abruption. All women were tested for the presence of lupus anticoagulant (LA), IgG/IgM anticardiolipin (ACL) antibodies, and IgG/IgM anti-2 glycoprotein-I (2 GPI) antibodies, as well as for risk factors for thrombophilia (proteins C and S, antithrombin III, homocysteine, mutations of Factor V (Leiden) and prothrombin G20210A, and increased resistance to activated protein C (RAPC)). Inclusion criteria were: (1) Pregnancy morbidity according to Sapporo criteria in the absence of clinical and/or laboratory data consistent with other systemic autoimmune diseases, (2) More than one previous untreated pregnancy and more than one APS regimen-treated pregnancy. Patients with LA were excluded from the study in order to be able to assess the significance of low aPL levels (in patients from both Group 1 and Group 2, as defined in the next
223
paragraph). As recommended, aPL persistence was confirmed in all patients (Miyakis et al., 2006). Patients were divided into two groups: Group 1: patients with obstetrical APS with clinical and laboratory features in accordance with Sapporo criteria (Miyakis et al., 2006); Group 2: patients with obstetrical events consistent with clinical APS according to Sapporo criteria, but with an aPL level below an intermediate cut-off level. A control group of patients with obstetrical APS-like untreated pregnancies, but without aPL was also considered. Antibody assays All aPL determinations were performed in our university laboratory (UF Autoimmunité et Hypersensibilité, Hôpital Bichat-Claude Bernard). Screening for LA was based on dilute Russell’s viper venom time (DRVVT) and dilute activated partial thromboplastin time (DAPTT). ACL and anti-2 GPI antibodies were determined using commercial enzyme-linked immunoabsorbent assays (INOVA Diagnostics, San Diego, CA, USA). Cut-off values for intermediate titers (99th percentile) were 20 U/ml (GPL/MPL units) for ACL and 15 IU/ml for IgG and IgM anti-2 GPI. The aPL titer was low if included between the 90th and 99th percentile for either antibody. In a control group of 70 women without any obstetrical morbidity, low-titer aPL was present in 2.8% in our university laboratory. Treatment and outcomes Antiphospholipid syndrome treatment consisted of low-dose aspirin (100 mg/day) with or without LMWH (40 mg enoxaparin once daily). Neonatal outcome was assessed by the following: delivery mode, weeks of gestational age at delivery, birth weight, height and cranial circumference, 1- and 5-min Apgar score, and neonatal complications. Statistical analysis Quantitative data were expressed as medians with ranges and qualitative data as frequencies and percentages. Fisher’s exact test was used to compare qualitative variables and the Mann–Whitney U test or Wilcoxon’s test, as appropriate, to compare continuous variables. We used GraphPad Prism software (version 5.1; 2007). The significance level was set at p < 0.05. Results Patient characteristics A total of 57 patients met our inclusion criteria (median age 36 years; range, 27–45). Group 1 (confirmed APS) comprised 25 patients (median age 38 years, range, 27–45); 13 Caucasian (52%). Group 2 (APS-like obstetrical events and
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A. Mekinian et al. / Journal of Reproductive Immunology 94 (2012) 222–226
Table 1 Patient’s characteristics in untreated pregnancies. Confirmed APS (n = 25)
Low aPL level (n = 32)
aPL-negative patients (n = 21)
Patient characteristics Age (years) BMI (kg/m2 ) Tobacco use Hypertension/diabetes mellitus Thrombosis
38 (27–49) 26 (17–34) 2 (8) 3 (12) 2 (8)
34 (23–45) 23 (18–34) 4 (13) 3 (9) 5 (16)
Type of obstetrical event Three or more abortions <10th week of gestation Fetal death (≥1) Preeclampsia/eclampsia <34 weeks Placental abruption IUGR Total obstetrical events/patient
9 (36) 11 (44) 5 (20) 3 (12) 9 (36) 3 (1–8)
13 (41) 16 (50) 6 (19) 3 (9) 7 (22) 3 (1–6)
6 (29) 9 (42) 5 (29) 0 0* 3 (1–6)
APS laboratory data ACL IgG (number with frequency of positive values) ACL IgM Anti-2 GP1 IgG Anti-2 GP1 IgM
18 (72) 6 (24) 6 (24) 1 (4)
16 (50) 14 (44) 4 (13) 6 (19)
– – – –
Thrombophilia Protein S (%) Protein C (%) Antithrombin III (%) RAPC Homocysteine (mol/l) Factor V Leiden Prothrombin G20210A mutation
63 (25–91) 100 (80–130) 100 (77–123) 2.2 (2–2.3) 10 (6–47) 0 0
63 (30–95) 97 (64–160) 100 (10–110) 2 (1.5–2.5) 6 (4–14) 0 0
30 (24–45) 22 (17–41) 0 1 (5) 0
75 (55–100) 100 (80–100) 100 (77–100) 2.3 (2.2–2.7) 10 (7–10) 2 (10) 2 (10)
BMI: body mass index; IUGR: intrauterine growth restriction; APS: antiphospholipid syndrome; ACL: anticardiolipin; anti-2 GP1: anti-2 glycoprotein-I; RAPC: resistance to activated protein C. Values are medians with ranges in brackets or numbers with percentages in parentheses. * p < 0.05.
low-titer aPL) comprised 32 patients (median age 34 years, range, 23–45); 18 Caucasian (56%). Pretreatment clinical and laboratory data (aPL and thrombophilia) are given in Table 1 for both groups of patients. No difference between the two groups was noted concerning the number of patients with different obstetrical events (Table 1). Screening for APS was performed before pregnancy in 16/25 Group 1 patients and 17/32 Group 2 patients, and during pregnancy in all other patients. The total number of obstetrical events per patient was highly similar in both groups (3 [1–8] in Group 1; 3 [1–6] in Group 2). A group of 21 patients with obstetrical events, but without detectable aPL was analyzed and had a similar number of obstetrical events (Table 1). Antiphospholipid isotype frequencies were similar in the two groups and persisted with the same isotype and levels in most of the patients at the second determination at 12 weeks. At the second aPL determination, aPL isotype changed in one case in each group (ACL G versus anti-2 GPI G and ACL IgG versus ACL IgM); and anti-2 GPI G disappeared in three cases (n = 1 in Group 1 and n = 2 in Group 2; in these 3 patients associated ACL G persisted at the second determination). As ACL IgG was the predominant isotype in Group 1, only ACL IgG and not ACL IgM levels were compared between groups. The ACL IgG level was significantly higher in Group 1 than in Group 2 (22 [0–344] vs. 9 [0–20] U/ml; p < 0.0001). Risk factors for thrombophilia were similar in the two groups. No mutations of Factor V (Leiden) or prothrombin G20210A were detected.
Pregnancy and neonatal outcomes on APS treatment Median follow-up was 8 years (range, 4–16). The APS treatment regimen did not differ statistically between the groups. Treatment was introduced as from 12 weeks (range, 4–27) of pregnancy in Group 1 and 10 weeks (range, 5–25) in Group 2. Aspirin plus LMWH was administered in 21 (84%) cases of Group 1 and 27 (84%) cases of Group 2, LMWH alone in 2 cases each and aspirin alone in 2 and 3 cases, respectively (8% and 9%). No treatment was administered in the control group of patients without aPL. Outcomes in the patients treated are shown in Table 2. The total number of obstetrical events per patient decreased significantly in both groups after treatment to reach an identical median value (from 3 [1–8] to 0 [0–2] in Group 1 (p < 0.05) and from 3 [1–6] to 0 [0–2] in Group 2 [p < 0.05]). After treatment, the incidence of premature births, the proportion of cesarean sections, and the characteristics of neonates were similar in the two groups. Only two neonatal complications were noted in each group (neonatal infections and respiratory distress syndrome in two cases, respectively). No cases of thrombosis or neonatal lupus were reported. Discussion Our study has revealed, to our knowledge for the first time, that pregnancy outcomes in untreated patients with APS-like obstetrical events and low aPL levels are poor and
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Table 2 Patient’s pregnancy outcome and neonate characteristics under treatment during pregnancy. Confirmed APS(n = 25)
Low aPL level(n = 32)
0 0 0 0 3 (12) 3 (12) 0 (0–2) 1 (3) 4 (16)
0 2 (6) 1 (3) 0 1 (3) 4 (13) 0 (0–2) 0 4 (13)
2 (8) 21 (84)
3 (9) 27 (84)
Delivery Spontaneous vaginal delivery Cesarean section Term (weeks) Term <37 weeks
17 (68) 8 (32) 38 (29–40) 9 (36)
21 (66) 14 (44) 38 (24–41) 10 (31)
Characteristics of neonates Female Weight (g) Weight <2500 g Height (cm) Cranial circumference (cm) Apgar 1/5 min Neonatal complications
14 (56) 3100 (1150–3770) 6 (24) 49 (40–52) 35 (25–37) 10 (3–10)/10 (5–10) 2 (8)
17 (53) 3250 (510–4540) 4 (13) 49 (40–54) 35 (29–37) 10 (1–10)/10 (3–10) 2 (6)
Type of obstetrical event Three or more abortions <10th week of gestation Fetal death (≥1) Preeclampsia/eclampsia <34 weeks Placental abruption IUGR Premature delivery Total obstetrical events/patient Thrombosis during pregnancy Infections during pregnancy Treatments during pregnancy Aspirin alone (100 mg/day) Aspirin with LMWH
IUGR: intrauterine growth restriction. Values are medians with ranges in brackets or numbers with percentages in parentheses.
similar to those in obstetrical patients with confirmed APS. Conventional APS treatment substantially improved pregnancy and neonatal outcomes in both groups of patients. Antiphospholipid syndrome is usually diagnosed using clinical and laboratory Sapporo criteria. However, the aPL level that is associated with a clinical risk has not been established in practice. The threshold used in the Sapporo criteria is a moderate-to-high aPL level even though thrombotic and obstetrical complications have been reported in patients with low aPL levels (Roubey, 1994; Amaral et al., 2010; Reznikoff-Etievant et al., 1999). We here have substantiated a relationship between low aPL levels and obstetrical APS and confirmed our previous data that obstetrical APS tends to be associated with a single positive aPL test, and thus possibly represents a less active immunological disease than thrombotic APS (Boffa et al., 2009). Usually IgG antibodies are thought to correlate better with thrombosis than IgM antibodies and predominant single aPL positivity is characteristic of obstetrical APS (Boffa et al., 2009; De Laat et al., 2009). Pregnancy is a hypercoagulable state and inherited or acquired thrombophilia factors could be associated with adverse outcomes (Kupferminc, 2003). Few studies have evaluated the presence of additional prothrombotic factors in patients with APS, and their results are conflicting (Kist et al., 2008; Kupferminc, 2003). In our study, thrombophilia factors were similar between the two groups, with normal median values, and could thus not account for the adverse pregnancy outcomes in patients with low aPL levels. In line with the results of published studies, conventional APS treatment much improved pregnancy outcomes
(type of obstetrical event and total number of events per patient) in patients with confirmed APS. However, treatment also improved outcomes in patients with low aPL levels. Median term and birth weight, height and cranial circumference were normal in both groups after treatment. Only two neonatal complications were noted after treatment in each group. The limitations of our study were first its retrospective design. Similar obstetrical events were noted in patients with APS, low-titer patients and the control group before treatment; even the absence of treatment in the control group did not allow the comparison of pregnancy outcome after treatment. We compared morbidity in low versus moderate-to-high titer aPL groups, but small patient numbers ruled out comparisons relative to the type of obstetrical event and type of aPL, and also ruled out a comparison between treatment by aspirin alone and by aspirin plus LMWH. Furthermore, we did not assess the relationship of low-titer aPL outcomes with LA, even though LA tends to be associated with thrombosis and more adverse pregnancy outcomes. On the other hand, a strength of our study was its consistency. Treatment was identical irrespective of aPL titer; a single laboratory performed all aPL determinations and the prevalence of low-titer aPL was only 2.8% in the same laboratory. In conclusion, in our study patients with low aPL levels have similar outcomes, in particular with respect to obstetrical events, as patients who meet Sapporo criteria for APS diagnosis. In this study treatment of patients with low aPL levels and APS-like obstetrical events was associated with outcomes similar to those found in otherwise normal women with recurrent miscarriage or other adverse
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events. However, properly designed treatment trials would be required to prove the benefit of such treatments. Conflicts of interest None. Funding source Department funds. Author’s contributions All authors were involved in drafting the article. O. Fain had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of data analysis. Study conception and design were done by AM and OF. AM, PLB, JS, PNR, EL, MCB, SCM, LC and OF have done the data acquisition. Analysis and interpretation of data were performed by AM and OF. References Amaral, M., Favas, C., Alves, J.D., 2010. Persistency of low levels of anticardiolipin and anti-beta2 glycoprotein 1 in thrombosis. Eur. J. Intern. Med. 21, 101–103. Boffa, M.C., Boinot, C., De Carolis, S., Rovere-Querini, P., Aurousseau, M.H., Allegri, F., et al., 2009. Laboratory criteria of the obstetrical antiphospholipid syndrome. Data from a multicentric prospective European women cohort. Thromb. Haemost. 102, 25–28.
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