Anti-heart antibodies in postpericardiotomy syndrome: cause or epiphenomenon? A prospective, longitudinal pilot study.

OBJECTIVES: To assess the role of anti-heart antibodies (AHA) in postpericardiotomy syndrome (PPS) and the timing of their appearance in relation to the initial manifestations of PPS. DESIGN AND SUBJECTS: Twenty patients who were scheduled to undergo elective coronary artery bypass grafting (CABG) were enrolled in a prospective, longitudinal pilot study. METHODS: Serum was sampled for AHA on the day prior to surgery and at regular intervalsfollowing surgery in all patients. In those who developed PPS, the serum AHA was determined on the day that typical clinical manifestations of PPS appeared and at regular intervals following the onset of PPS. RESULTS: All patients were negative for AHA on the day precedingsurgery. Three(15%) patients developed PPS. Their sera were negative for AHA on the day they were diagnosed as sufferingfrom PPS and the sera became positive for AHA within 14 days from the time of diagnosis. The intensity of immunofluorescence decreased markedly 30 days afterwards and AHA had disappeared within 90days after diagnosis of PPS. The other 17 (85%) patients were negative for AHA prior to surgery and remained so during the six-month postoperative follow-up period. CONCLUSION: The findings of this study suggest that serum AHA may not play a causal role inthe pathogenesis of PPS, but may rather be an epiphenomenon, reflecting an immune response to pericardial and/or myocardial injury.

Dissection of the humoral immune response toward an immunodominant epitope of HIV: a model for the analysis of antibody diversity in HIV+ individuals.

Understanding the dynamics of the humoral immune response to HIV epitopes in the presence of genetic drift and antigenic variation of the virus may reveal critical elements of protective immunity against HIV. Analysis of antibody maturation and diversity is difficult to study at the molecular level in humans. We used a combinatorial phage display peptide library to elucidate antibody diversity in HIV-infected individuals to a single immunodominant epitope in gp41. A serum sample derived from an HIV+ individual was used to screen a phage display a 12 mer cysteine-constrained loop peptide library. In doing so, we isolated mimotope-presenting phages corresponding to the immunodominant gp41 epitope CSGKLIC (residues 603-609). The mimotopes and control phages expressing epitope variants were reacted with a panel of 30 HIV+ sera. The patients showed distinct and variable recognition patterns compared with one another. Subfractions of the polyclonal sera were affinity purified and analyzed for epitope specificities. These analyses illustrated that epitope variants can be used to decipher antibody diversity. Elucidation of the plasticity of the humoral response and its polyclonality toward discrete epitopes contributes to our understanding of the antibody maturation process in individuals infected with viruses such as HIV.

Genotypic variation of HIV-1 reverse transcriptase and protease: comparative analysis of clade C and clade B.

OBJECTIVE: To compare drug-resistant variants from untreated (naive) and treated patients infected with clade B or C virus. METHODS: Consecutive samples (165) from patients throughout Israel were analyzed. All those in the treated group were failing highly active antiretroviral therapy. RESULTS: There were 87 clade B (14 naive) and 78 clade C (20 naive) [corrected] with significant differences in the prevalence of known drug-resistance mutations between the clades: in naive patients in the protease region M36I 7% and 95% (P < 0.0001), K20R 0% and 27% (P = 0.063), A71V 18% and 0% (P = 0.063), M46I 0% and 13%, and V77I 18% and 0% (P = 0.063), respectively, and in the reverse transcriptase region A98G/S 0% and 20% (P = 0.12), respectively. Most clade C viruses also showed significant differences from clade B consensus sequence at additional protease sites: R41K 100%, H69K/Q 85%, L89M 95% and I93L 80% (P < 0.0001). There were also significant differences (P < 0.03 to < 0.0001) in treated patients in clades B and C: in the protease region L10I 40% and 12%, M36I 26% and 95%, L63P 67% and 40%, A71I 38% and 7%, G73I and V77I 18% and 0%, I84V 16% and 3%, and L90M 40% and 12%, respectively; in the reverse transcriptase M41L 41% and 17%, D67N 41% and12%, K70R 30% and 7%, T215Y 48% and 29%, K219Q 21% and 7%, and A98G/S 3% and 24%, respectively. CONCLUSION: Significantly differences between clade B and C viruses may be associated with development of differing resistance patterns during therapy and may affect drug utility in patients infected with clade C.

Clinical significance of low titer anti-nuclear antibodies in early rheumatoid arthritis: implications on the presentation and long-term course of the disease.

The objective of this study was to evaluate the clinical significance of anti-nuclear antibodies (ANA) detected in the early stages of rheumatoid arthritis (RA), by a retrospective comparison of the clinical, laboratory, and therapeutic characteristics of patients with or without ANA. The files of 99 longstanding seropositive RA patients were reviewed. Data relating to demographics, medical history, family history, physical findings, extra-articular complications, laboratory tests, drugs [dosage, duration. efficacy, combinations, adverse effects (AEs)], intra-articular injections, and surgery were recorded. Patients with or without ANA at presentation of their disease were compared using chi-square and t-tests. Fifty-two ANA positive (group 1) and 47 ANA negative (group 2) patients were enrolled in the study. All were comparable in terms of their mean age, age at diagnosis, follow-up duration (approximately 10.5 years), and male:female (M:F) ratio. On admission, pain complaints were more pronounced in group 1 (P = 0.004 in the feet), but the physical findings did not differ. Deformities and nodules developed in similar numbers. Extra-articular complications were evenly distributed; vasculitis, however, was significantly more prevalent in ANA positive (10/52) than in ANA negative (2/47) patients. Thyroid disease was more common in group 2 (10/47 vs 3/52). Laboratory tests (presentation and maximal values) were similar, with the exception of higher anti-DNA (but within normal ranges) and gamma-globulin% in group 1. Group 1 used more drugs prior to diagnosis. Corticosteroids and disease-modifying anti-rheumatic drugs (DMARDs) were evenly used. Combination therapy, joint injections, and surgery were more prevalent in group 2. AEs to various DMARDs were more common in group 1. Although similar in many aspects, RA patients with ANA tend to present with more pain complaints, a higher risk of vasculitis and AEs relating to use of DMARDs, while those without ANA needed more aggressive therapeutic modalities.

Comparison of assays for anti-endomysial and anti-transglutaminase antibodies for diagnosis of pediatric celiac disease.

BACKGROUND: Anti-endomysial antibodies are sensitive and specific markers for celiac disease. This antibody has recently been identified as an antibody to tissue transglutaminase, an enzyme that cross-links and stabilizes extracellular matrix proteins. OBJECTIVES: To evaluate the clinical usefulness of an enzyme-linked immunoassay for anti-transglutaminase antibodies, and to compare the results with those of AEA, the current gold standard serological test for celiac disease. METHODS: Serum samples were collected from 33 patients with biopsy-proven celiac disease and AEA tests were performed. Control samples for anti-transglutaminase were obtained from 155 patients. An ELISA test for immunoglobulin A anti-transglutaminase utilizing guinea pig liver transglutaminase was developed and performed on all sera. Cutoff values for the test were performed using logistic regression and receiver operating curves analysis. RESULTS: An optical density cutoff value of 0.34 was established for the assay. The mean value was 0.18 +/- 0.19 optical density for controls, and 1.65 +/- 1.14 for patients with celiac disease (P < 0.001). Sensitivity and specificity of the assay were both 90%, while AEA had a sensitivity and specificity of 100% and 94%, respectively. CONCLUSIONS: A tissue transglutaminase-based ELISA test is both sensitive and specific for detection of celiac disease.

Dementia and antiphospholipid antibodies.

Antiphospholipid antibodies (aPLAb) may cause both focal ischemic and diffuse brain damage and may be associated with dementia. We have examined the relationship of aPLAb to dementia in the elderly. Blood samples were obtained from 87 consecutive patients with dementia (74 +/- 11 years old) and 69 controls (78 +/- 9 years old), residents of an old age home who were not overtly demented. Levels of aPLAb were measured by a standardized ELISA, utilizing cardiolipin as antigen, and we considered levels above 20 IgG antiphospholipid units (GPLU) as significantly elevated. We found that 5 of the 87 demented patients (6%), but none of the 69 controls, had significantly elevated aPLAb levels (p = 0.03, one-tailed Fisher's exact test). All the patients with high aPLAb levels were diagnosed clinically as having dementia of the Alzheimer type, except for 1 who had mixed dementia, and none had features of an immune-mediated disease. Thus, a small but significant number of patients with dementia have high levels of aPLAb. The role of the aPLAb in these patients, with apparently diffuse brain disease, is currently unknown.

Anti-HIV indeterminate western blot in dialysis patients: a long-term follow-up.

In a group of 520 patients undergoing chronic hemodialysis, 23 (4. 4%) were enzyme immunoassay (EIA) positive for human immunodeficiency virus (HIV) and indeterminate by Western blot (IWB) analysis. The antibodies were mostly directed against p24 and p55 antigens. A comparison between hemodialysis patients with and without IWB showed significant differences between the two groups with respect to number of units of blood transfused, history of renal transplant rejection, and Rh status. No significant differences were observed with respect to ethnic group, nature of renal disease, duration of hemodialysis, associated diseases, and ABO blood group. The HIV IWB phenomenon may represent abnormal immune reactivity as a result of transplantation antigens and/or autoantibody formation. Five-year follow-up of the HIV EIA-positive IWB patients showed that none had seroconverted to HIV-positive status.

Increased intracellular accumulation of macrophage inflammatory protein 1beta and its decreased secretion correlate with advanced HIV disease.

Considering that the chemokine macrophage inflammatory protein 1beta (MIP1beta) may serve as a competitive inhibitor for HIV entry, the objective of this study was to compare intracellular and extracellular levels of MIP1beta, in untreated HIV-infected individuals. HIV patients and healthy controls were tested by two-color flow cytometry for intracellular MIP1beta, in freshly explanted CD4 and CD8 lymphocytes, and in monocytes. Sera and plasma collected on the same day were tested, respectively, by enzyme-linked immunosorbent assay (ELISA) for MIP1beta concentration and for number of HIV-RNA copies, using nucleic acid sequence-based amplification procedure (NASBA) methodology. Results demonstrate that a high intracellular level of MIP1beta appears to be linked to a deterioration in the immune status of HIV patients (i.e., low CD4 counts) and to a high viral load. Moreover, an inverse relationship exists between the intracellular and the "secreted" form of MIP1beta, thus leading to the hypothesis that the regulation of cellular accumulation and secretion of MIP1beta and of other chemokines may be disrupted during AIDS development.

Immunologic responses of HIV-1-infected study subjects to immunization with a mixture of peptide protein derivative-V3 loop peptide conjugates.

V3 loop peptide sequences from several HIV-1 strains were covalently linked to purified protein derivative (PPD) of Mycobacterium tuberculosis. A mixture of PPD conjugates of V3 loop peptides from six different strains of HIV-1 induced a stronger antibody response than a single V3 peptide-conjugate administered to guinea pigs and humans. Sera from animals immunized with a PPD-six peptide-PPD conjugate neutralized multiple primary-isolate strains of HIV-1. Potent immune responses were noted only when animals were primed with bacillus Calmette-Guerin (BCG), PPD was covalently bound to the peptides, and PPD was used as the carrier protein. Based on these animal studies, an immunogen consisting of PPD-conjugated V3 loop peptides from five HIV-1 strains was tested in 7 HIV-1 seropositive PPD skin test positive study subjects. Vaccinees exhibited over time a uniform increase in neutralizing antibodies for both laboratory adapted and primary isolates of HIV-1, including strains from multiple clades. In 3 patients with baseline viral loads between 8000 and 12,000 RNA copies/ml, the viral load declined in 2 patients to <400 copies/ml and in 1 patient to 1200 copies/ml without concurrent administration of highly active antiretroviral therapy (HAART).

Clinical and immunological study of 7 patients with minocycline-induced autoimmune phenomena.

PURPOSE: Prolonged treatment with minocycline for acne vulgaris has been associated with the development of arthralgia, arthritis, and other autoimmune phenomena. We characterized the clinical, laboratory, and immunological profiles of seven patients with this syndrome. SUBJECTS AND METHODS: Clinically the patients were studied with special emphasis on prior minocycline treatment, presenting symptoms, physical findings, course, and outcome. Laboratory tests included fluorescent antinuclear and antineutrophil cytoplasmic (ANCA) antibodies, as well as antibodies to myeloperoxidase, bactericidal permeability increasing protein, elastase, cathepsin G, lactoferrin, cardiolipin, and histone. RESULTS: All 7 patients presented with polyarthritis or arthralgia, morning stiffness, and fever after 6 to 36 months of minocycline treatment. The skin was involved in five patients (three with livedo reticularis and two with subcutaneous nodules). Two patients had chronic active hepatitis. Increased titers of perinuclear ANCA (p-ANCA) were detected in all seven patients; five patients had fluorescent antinuclear antibodies, two had antihistone autoantibodies and one had anticardiolipin antibodies. Antigenic characterization of p-ANCA disclosed antibodies to bactericidal permeability increasing protein in one patient, to elastase in three patients, and to cathepsin G in five patients. Symptoms resolved in five patients upon discontinuation of minocycline; the other two patients were treated with corticosteroids and also achieved remissions. CONCLUSION: Minocycline-induced autoimmune syndrome is characterized by reversible polyarthralgia or arthritis, morning stiffness, fever, frequent skin involvement, occasional chronic active hepatitis, and increased titers of p-ANCA with various minor p-ANCA-related antigens.

Serum amyloid type A may be a predictor of restenosis.

BACKGROUND: Elevation of acute phase proteins [C-reactive protein (CRP) and serum amyloid type A (SAA)] has been demonstrated in unstable angina with an adverse clinical prognosis. HYPOTHESIS: The study was undertaken to determine the effect of angioplasty on the levels of SAA and the correlation with postangioplasty restenosis. METHODS: In a university-affiliated tertiary medical center, a prospective case study was undertaken in 55 patients who underwent successful percutaneous transluminal coronary angioplasty (PTCA) of a single coronary lesion for angina pectoris. Three groups of patients were clinically characterized according to Braunwald's classification of anginal syndrome: Group A: class III; Group B: class I; Group C: stable angina. Serum amyloid type A was measured by an ELISA method before PTCA and after 24 h, 1, and 3 months. Patients were followed clinically for 12 months. A thallium stress perfusion scan was performed 3 months after PTCA and coronary angiography was repeated in patients with an abnormal thallium perfusion scan. RESULTS: Serum amyloid type A levels > 100 micrograms/ml could identify Group A patients with a high sensitivity and specificity (r = 0.85 and 0.86, respectively). Of the patients studied, 75% increased their SAA level 24 h after angioplasty. An increase of SAA by > 100% was associated with an increased risk of restenosis, with a relative risk of 6.4 (p < 0.05). CONCLUSION: Increased levels of SAA characterize patients with unstable angina pectoris with a high specificity and sensitivity. Levels of SAA that increase > 100% 24 h after angioplasty may serve as a marker of restenosis.

Increased intracellular macrophage inflammatory protein-1beta correlates with advanced HIV disease.

The objective of this study was to correlate between macrophage inflammatory protein-1beta (MIP1beta) and viral loads in untreated, HIV-infected individuals. For that purpose, HIV-positive patients were tested for number of copies of HIV-RNA in plasma and for intracellular MIP1beta in freshly explanted CD8 and CD4 lymphocytes and monocytes. Results demonstrate that the levels of MIP1beta in the various cell populations were significantly higher in the HIV group than in age-matched healthy individuals. Moreover, patients with low CD4 cell counts (<500/microl) and relatively high viral loads exhibited much higher levels of intracellular MIP1beta than patients with lower viral loads and CD4 counts >500/microl. We conclude therefore that although MIP1beta is induced in the various cell populations as a result of HIV infection in vivo, a high intracellular level of MIP1beta appears to be linked to a deterioration in the immune status of the patients.

Predictive value of response to treatment of T-lymphocyte subpopulations in idiopathic pulmonary fibrosis.

T-cell types are important in maintaining immune homeostasis in the lung and their imbalance may be associated with several diseases. We examined the relationship between bronchoalveolar lavage (BAL) T-cell subset profiles and the clinical course of 46 patients with idiopathic pulmonary fibrosis (IPF). A flow cytometry cell sorter (FACS) was used to analyse the T-cell subsets. Pulmonary function tests (PFT) were performed at baseline and 6-12 months later. Patients were divided into two groups according to their CD4/CD8 ratio: CD4/CD8 >1 (group 1, n=21); and CD4/CD8 <1 (group 2, n=25). A lower percentage of lymphocytes, a higher percentage of CD8/S6F1 cells (cytotoxic T-lymphocytes) and a higher percentage of neutrophils were found in the BAL in group 2 compared to group 1 (11+/-7.5% versus 19+/-13.2%; p=0.024 and 29.8+/-17.6% versus 13.3+/-6.9%; p=0.068, respectively for lymphocytes and cytotoxic T-lymphocytes; and 8+/-11% versus 29+/-27%; p=0.003 for neutrophils). Inversely, in the peripheral blood, the distribution of CD8/S6F1 cells was lower in group 1 than in group 2 (8.3+/-6.9% versus 33.4+/-16.5%; p=0.0048). The patients were followed over a period of 1 yr in order to test whether those findings could determine efficacy of therapy. The baseline transfer factor of the lung for carbon monoxide (TL,CO) capacity in group 1 and group 2 was 59+/-22% and 51+/-21%, respectively (p=0.29), but only in group 1 was the TL,CO capacity improved significantly in response to steroids treatment after 6-12 months. IPF patients with a higher percentage of lymphocytes, a lower percentage of neutrophils, CD4/CD8 >1 and a low percentage of CD8/S6F1 may have a more benign course of disease. These parameters may identify an early stage of reversible disease responsive to therapy. We conclude that these measurements may be a useful tool in monitoring response to treatment in patients with idiopathic pulmonary fibrosis.

Autoimmune and inflammatory responses may have an additive effect in postpercutaneous transluminal coronary angioplasty restenosis.

Patients who had an increase in their serum amyloid type A level of > 100% in the first 24 hours after percutaneous transluminal coronary angioplasty (PTCA) and also developed a positive antibody result (antinuclear factor or anticardiolipin), had a relative risk of 10.6 for developing restenosis in the first year after PTCA.

Molecular epidemiology of HIV in Israel.

The aim of this study was to identify the HIV types and subtypes prevalent in Israel among different populations in terms of risk or geographic origin of the HIV infection. A total of 149 blood samples were collected from HIV-positive persons from different risk groups for HIV infection who were living in Israel. HIV subtyping was performed by a V3-based peptide enzyme immunoassay, supplemented by direct sequencing of polymerase chain reaction products from the V3 region. Multiple HIV-1 subtypes were shown to circulate in Israel; whereas most of the infections among Israelis and Palestinians were of subtype B, infections among the large Ethiopian population in Israel were caused by HIV-1 subtype C. Occasionally, we found HIV-1 subtypes A and D and a putative B/C recombinant. No HIV-2 infection was identified. Sequence comparisons and phylogenetic tree analyses point at multiple introductions of HIV into the country. The presence of mainly two different HIV-1 subtypes, B and C, in two separated populations in Israel may result in two distinct epidemiologic patterns among HIV-infected individuals in Israel. Subtype C infection among the Ethiopians in Israel opens new research avenues toward better understanding the natural history of infection with HIV-1 subtype C in Ethiopians living in a Western society compared with those living in Ethiopia.

Cytomegalovirus retinitis in patients with AIDS in Europe. AIDS in Europe Study Group.

The incidence of cytomegalovirus (CMV) retinitis and risk factors associated with the condition were studied in patients with the acquired immune deficiency syndrome (AIDS) in a multicenter retrospective cohort study of 6458 patients from 52 centers in 17 countries in Europe. Cytomegalovirus retinitis was diagnosed in 154 patients (2.4%) at the time of AIDS diagnosis, the probability of this diagnosis being significantly higher for those with CD4+ cell counts of < 100/mm3 (3.4%) than with counts of 100-200/mm3 (1.3%) or > 200/mm3 (0.8%). The rate of developing CMV retinitis after AIDS diagnosis was 9.4 per 100 patient years of follow-up. Multivariate analysis showed that risk behavior was significantly associated with the risk of developing CMV retinitis: lower for intravenous drug users [relative risk (RR) 0.47] and those engaged in "other risk behavior" (RR 0.58) than for homosexual men. The risk of developing CMV retinitis after AIDS diagnosis was significantly associated with CD4+ cell count at the time of AIDS diagnosis: for counts < 100/mm3 (RR 2.90) and from 100 to 200/mm3 (RR 2.13), there was a higher risk than for counts > 200/mm3. Patients with Pneumocystis carinii pneumonia, toxoplasmosis, or extraocular CMV infection at time of AIDS diagnosis exhibited an increased risk of developing CMV retinitis. Patients treated with zidovudine exhibited an increased rate of CMV retinitis: RR was 1.75 during and 2.87 after the second year of treatment as compared to those who had not received zidovudine. Median survival after CMV retinitis at time of AIDS diagnosis was eight months.

Organ-specific autoantibodies are possible markers for reproductive failure: a prospective study in an in-vitro fertilization-embryo transfer programme.

This study was conducted to investigate the usefulness of organ-specific autoantibodies as possible markers for reproductive failure. Antithyroid and antiovarian autoantibody concentrations were measured in 78 patients with mechanical or unexplained infertility that were enrolled in an in-vitro fertilization (IVF)/embryo transfer programme with follow-up of the outcome. In all, 16 patients (20.5%) were positive for antithyroid antibodies, nine (11.5%) were positive for antiovarian autoantibodies and two (2.6%) were positive for both autoantibodies. All 23 patients who were positive for either antithyroid or antiovarian autoantibodies, or both, were defined as the study group, and 55 who were negative for autoantibodies were considered as the control group. No statistical difference in the incidence of autoantibodies was found between the patients with mechanical infertility and those with unexplained infertility. No differences were found in the mean number of oocytes retrieved, fertilization rates or mean numbers of transferred embryos between the study and the control groups. The pregnancy rate per cycle was 10.8% (7/65) in the study group, compared with 25.0% (24/96) in the control group (P < 0.05). We conclude that organ-specific autoantibodies such as antithyroid and antiovarian antibodies may serve as possible markers for reproductive failure. Further investigation is required to understand the possible immunopathological mechanism for reproduction failure in patients with organ-specific autoantibodies.

High-dose intravenous magnesium attenuates complement consumption after acute myocardial infarction treated by streptokinase.

OBJECTIVE: This study was designed to detect changes in complement levels following acute myocardial infarction and to test whether magnesium sulphate (MgSO4) administration interferes with the complement response that follows acute myocardial infarction. DESIGN: Twenty-nine patients with acute myocardial infarction treated with streptokinase were included and randomly assigned to three treatment groups. In groups A and B, a bolus of 1 g MgSO4 was infused intravenously followed by 4 g (group A) and 14 g (group B) MgSO4 for 24 h while normal saline was administered in group C (control). Blood samples for C3, C4 and CH-100 were obtained at baseline and repeatedly during the 48 h following the initiation of magnesium infusion. RESULTS: In groups A and C, a remarkable decrease in the levels of C3, C4 and CH-100 was observed when measured 1 h after the end of streptokinase infusion and thereafter for the ensuing 48 h compared to baseline values (P < 0.05). In group B, the decrease in these complement elements was attenuated, and a significant (P < 0.05) delayed decrease of C3 and C4 was observed only at 24 h and later up to 48 h. The mean level of CH-100 in group B was significantly depressed compared to baseline from 3 h and thereafter up to 48 h. Mean C3 values plotted against observation time differed between the three groups (P = 0.021). A similar trend was observed for C4 (P = 0.133) but not for CH-100 (P = 0.46). CONCLUSION: (1) Complement elements are being consumed following acute myocardial infarction treated by streptokinase. (2) High-dose intravenous magnesium attenuates the complement process following acute myocardial infarction. (3) These results might signify that magnesium modulates the inflammatory response that follows infarction.

HIV-2 infection in Israel: a new epidemic?

AIDS may be caused by two different retroviruses, HIV-1 and HIV-2. Hitherto only HIV-1 has been reported in Israel. We recently discovered HIV-2 as a solitary pathogen in the blood of two foreign workers from West Africa. In view of the relative ease of travel to Israel, it is essential to perform screening for both HIV viruses in all subjects with an enhanced risk, including visitors from countries with a high incidence of HIV-1 or HIV-2 infection and their contacts.

Circulating autoimmune antibodies may be responsible for implantation failure in in vitro fertilization.

OBJECTIVE: To investigate the role of autoimmune factors as a possible cause for implantation failure as manifested by chemical pregnancy after IVF and ET. DESIGN: Anticardiolipin, anti-double-stranded DNA (dsDNA), antinuclear antibody, lupus anticoagulant, and rheumatoid factor serum levels were examined in patients with chemical pregnancies and in matched controls. SETTING: An IVF unit, university-based IVF program. PATIENTS: The study group included 21 patients who had one or more chemical pregnancies and no deliveries. The control group consisted of 21 patients who had conceived and delivered after IVF-ET treatment, without any history of fetal wastage, matched for age, type and duration of infertility, and number of previous IVF cycles. RESULTS: The incidence of circulating autoimmune antibodies in the study group was 33.3% (7/21). Three patients (14.2%) were positive for anticardiolipin, two (9.5%) were positive for antidsDNA, one (4.7%) for antinuclear factor, and one (4.7%) for rheumatoid factor. Autoimmune antibodies were not detected in any of the control group. CONCLUSION: Autoimmunity may play a role in implantation failure in IVF-ET. Circulating autoimmune antibody screening is therefore recommended after chemical pregnancy.