Israel Medical Association Journal

Autoimmune diseases constitute a diverse group of disorders characterized by cellular and humoral responses against self. The humoral autoimmune responses are directed against various cellular and extracellular components. These responses are highly specific for each autoimmune disease and result in the production of autoantibodies that characterize certain disease entities, representing a valuable tool for the diagnosis of autoimmune diseases. Furthermore, certain autoantibodies are helpful in the prognosis of disease development, progression and severity, as well as in the classification of patients with distinct disease subtypes. Today, the value of autoantibodies in the follow-up of patients is limited, but preliminary data suggest that they may be useful in predicting response to treatment. 

Antiphospholipid syndrome (APS) is an autoimmune systemic disease characterized by vascular thrombosis (arterial or venous) and/or pregnancy complications associated with the occurrence of autoantibodies, specifically lupus anticoagulant, anticardiolipin antibodies, and/or anti-β2 glycoprotein-I antibodies confirmed at least twice over a 12 week period according to the 2006 Sydney criteria. Antiphospholipid antibodies are encountered  in the general population with a reported prevalence of 1% to 5%  However, APS is far more infrequent with a prevalence of 40–50/100,000 persons and an incidence of about 5 new patients/100,000 persons. APS can be diagnosed in patients with no apparent clinical or laboratory pathology (primary APS) or it may be related to numerous other conditions, autoimmune diseases (usually systemic lupus erythematosus), malignancies, infections and drugs (secondary APS). Women are at risk for APS since the disease is encountered in both the primary and the secondary state in females more often than in men. In addition, women in their reproductive years can develop APS (either classical or obstetric), and special attention is warranted in pregnant women with a diagnosis of APS. The benefits of hormonal therapy in the form of contraception or hormone replacement treatment should be carefully weighed against the increased risk for vascular complications in women with APS.

Background: Antiphospholipid antibodies (aPL) have been advocated as potential mediators of unexplained female infertility, but no evidence has yet been raised to support such an association.

Objectives: To test the hypothesis that aPL might interfere with uterine decidualization, a gene expression study was performed on decidual stromal cells treated with different aPL preparations.

Methods: Decidual stromal cells were isolated from first-trimester deciduas obtained from two women undergoing elective abortion, and treated with: (i) a β2GPI-dependent aPL monoclonal antibody (IS3); (ii) IS3 plus TIFI, a synthetic peptide mimicking PL-binding region of β2GPI; and (iii) IgG from healthy subjects (NHS). Gene expression data were acquired using human HT-12 v3 beadchip arrays (Illumina). Differential expression analysis was performed by fitting a gene-wise linear model using the treatment group and decidual source as covariates.

Results: In the comparison of IS3 versus IgG NHS-treated decidual cells, gene ontology (GO) enrichment was expressed in terms relating to well-characterized aPL-mediated cellular effects: “inflammatory response,” “immune response,” “response to stress,” “oxydoreductase activity,” “metalloendopeptidase activity,” and “cytokine/chemokine activity.” As expected, almost all genes were up-regulated by IS3 treatment. The same GO categories appeared to be differentially expressed when IS3 treatment was compared to IS3 + TIFI, but with most genes being down-regulated.

Conclusions: Given the inflammatory response evinced at gene expression analysis on decidual stromal cells treated with a β2GPI -dependent aPL monoclonal antibody, it is feasible that aPL might interfere with uterine decidualization, affecting the early stages of implantation and ultimately resulting in female infertility.

 

Background: The role of autoimmune factors in the etiology of coronary artery disease (CAD) was suggested in numerous studies but has not been definitively determined.

Objectives: To assess the possible influence of antiphospholipid and antinuclear antibodies on atherosclerosis development in young patients after myocardial revascularization procedures.

Methods: The study group included 39 patients younger than 45 years with coronary artery disease (CAD) who underwent myocardial revascularization. Serum levels of antiphospholipid (aPL), antinuclear (ANA) and antineutrophil cytoplasmatic (ANCA) antibodies were tested within 1 month after the procedure.

Results: All three types of aPL were significantly higher in CAD patients when compared to healthy controls: anti-β2-glycoprotein I (aβ2GPI), both immunoglobulin (Ig)G and IgM classes (median 4.10 SGU, range 3.45–21.63 vs. 0.76, 0.12–6.01, P < 0.001, and 2.82 SGU, 1.44–11.70 vs. 1.08, 0.44–3.64, P < 0.001, respectively); anticardiolipin antibodies (aCL) both IgG and IgM classes (3.13 GPL, 1.32–14.03 vs. 2.42, 0.96–18.45, P = 0.0037, and 6.94 MPL, 1.90–26.40 vs. 4.32, 1.9–28.73, P < 0.008, respectively); and lupus anticoagulant (LA) (27.7% vs. 0%, P = 0.005). ANA were elevated in one patient and ANCA in 23 (60%). The levels of aPL did not correlate with the presence of a clot in a coronary vessel detected during angiography or with exacerbation of coronary artery atherosclerosis.

Conclusions: In young patients with CAD who underwent myocardial revascularization the levels of aPL were significantly higher than in young healthy subjects. Thus, besides the classic risk factors for CAD, autoimmunity may play an important role in atherosclerotic plaque formation and progression.

Background: The association between antiphospholipid antibodies (aPL) and multiple sclerosis (MS) has been suggested previously, but prior studies provided contradicting findings. 

Objectives: To characterize the expression profile of eight classic and non-classic aPL in patients diagnosed with MS.

Methods: Using the BioPlex™ 2200 immunoassay, we measured the levels of serum immunoglobulin (Ig)M and IgG isotypes of three classic aPL and five non-classic aPL in 98 subjects with MS and 237 healthy controls. 

Results: Three non-classic aPL were significantly more prevalent among MS patients in comparison to the control group. These antibodies included IgM and IgG against phosphatidylserine-β2GPI (PS-B2), IgG prothrombin complex (PT-PT) and IgM prothrombin (PT). The positive results according to Bonferroni correction are PS-B2 IgG and PT-PT IgG. The remaining aPL profiles did not differ significantly between the two groups.

Conclusions: An association between certain non-classic aPL and MS has been established. The specific role of these autoantibodies in the pathogenesis of the condition remains uncertain.  

 

Thrombosis is a common phenomenon in patients with malignancies. It is believed that thrombosis is multifactorial and that in addition to mechanisms directly associated with cancer and its treatment, it may also be related to the interaction between the immune system and clotting. The present work describes four cancer patients (three adults and one child) whose clinical course was characteristic of catastrophic antiphospholipid syndrome (CAPS) in intensive care units of the National Cancer Institute of Rio de Janeiro. The presence of findings similar to those in CAPS can be attributed to an unbalanced interaction between the immune system and coagulation.

Background: Anti-red blood cell antibodies, free light chains (FLC) and prothrombotic proteins (PTP) may co-elute with intact immunogIobulin (IgG), and may be the cause of adverse reactions to intravenous immunoglobulin preparations (IVIG).

Objectives: To investigate the presence of residual amounts of these components in IVIG and their effects on ABO blood group agglutination.

Methods: Iso-agglutinin anti-A and anti-B activity was determined with a direct hemagglutination assay of red blood cell (RBC) suspensions from 1% of 46 blood donors together with the serial dilutions of five IVIG (IV1, IV2, IV3, IV4, IV5). Anti-A1 monoclonal antibody was used to confirm reactivity with the A1-reference RBC. The selected IVIG were diluted to a final concentration of 25 mg/ml in 0.15 M NaCl and 0.01 M phosphate-buffered saline (PBS), pH 7.4, with or without a further twofold dilution in a low ionic strength solution.

Results: A variation up to fivefold in the titer strength of anti-A/B activity was observed between the IVIG preparations. A2-type RBC required higher IVIG inputs when tested in 0.15 M NaCl. The differences in FLC kappa and lambda concentrations were as high as > 400 mg/L among the various IVIG. Only IV1 had a significantly high level of antiphospholipid IgG antibodies (18 U/ml). We demonstrated the presence of anti-RBC antibodies, FLC and PTP in IVIG preparations.

Conclusions: Our findings provide clear evidence that IVIG may harbor pathophysiological substrates with a potential risk for adverse effects such as iatrogenic hemolysis, FLC-associated disorders, and thromboembolism.