Human immunodeficiency virus rather than hepatitis C virus infection is relevant to the development of an anti-cardiolipin antibody

Cell damage at the origin of antiphospholipid antibodies and their pathogenic potential in recurrent pregnancy loss

Antiphospholipid antibodies (APA) are associated with thrombosis, thrombocytopenia and fetal loss but they occur in a variety of diseases. Despite many efforts, a correlation between the specificity of particular subgroups of APA and particular clinical situations remains to be established. The antigens at the origin of APA remain to be identified. We discuss here the possible links between cell apoptosis or necrosis, leading to plasma membrane alterations, and the occurrence of APA in response to sustained stimulation. The pathogenic potential of APA is also considered with respect to recurrent pregnancy loss.

Anticardiolipin antibodies in chronic hepatitis B and chronic hepatitis D infection, and hepatitis B-related hepatocellular carcinoma. Relationship with portal vein thrombosis

OBJECTIVE

To assess the presence of anticardiolipin antibodies (ACAs) in patients with chronic hepatitis B virus (HBV) infection, chronic hepatitis D virus (HDV) infection and HBV-related hepatocellular carcinoma (HCC) and to associate this with the incidence of portal vein thrombosis (PVT) in HCC patients.

PATIENTS AND METHODS

Sixty-five cirrhotic patients with HBV-related HCC, 28 naive patients with chronic HBV infection and 14 naive patients with chronic HDV infection were enrolled prospectively in the study. Thirty-two healthy blood donors were used as controls. The ACAs (immunoglobulin G and immunoglobulin M) were measured using an enzyme-linked immunosorbent assay system. Statistical analysis used non-parametric methodology (chi-squared test, Student t-test and Fisher exact test, P value<0.05).

RESULTS

Eleven of the 65 patients with HCC (16.9%) showed a positive ACA titre and 22 of the patients (34%) had PVT. Of these patients, eight (36%) had a positive ACA titre. In contrast, from the 43 patients without PVT, only three (11%) showed a positive titre. From the 28 HBV patients, six (21.5%) had a positive ACA titre, and six out of 14 (42.8%) HDV patients also showed a positive ACA titre. Three of the six ACA positive HBV patients presented an extrahepatic manifestation of the disease. One out of 32 control patients (3%) had positive ACAs.

CONCLUSION

Both chronic HBV and chronic HDV infections are potent stimulants for the production of ACAs. The presence of ACAs in a great proportion of HBV-cirrhosis-related HCC patients with PVT suggests their possible participation in thrombotic mechanisms and in the hypercoagulable state that occurs in advanced liver disease and HCC.

Anti-cardiolipin antibodies in patients with chronic viral hepatitis are independent of beta2-glycoprotein I cofactor or features of antiphospholipid syndrome

BACKGROUND

Although controversial, some authorities have implicated hepatitis C virus (HCV) as a cause of anti-phospholipid syndrome (APLS). Anti-cardiolipin antibodies (anti-CLAbs) in APLS are cofactor-dependent ('pathogenic' antibodies). We conducted a study in order to determine the prevalence of anti-CLAbs in HCV patients, and furthermore to address whether these autoantibodies are cofactor-dependent or not and whether they are associated with features of APLS. Patients with hepatitis B virus (HBV) were also evaluated in order to assess whether there are differences in the prevalence and the clinical significance of anti-CLAbs between these two major types of chronic viral hepatitis.

MATERIALS AND METHODS

One hundred and seventy-four consecutive HCV patients, 50 HBV patients and 267 healthy were investigated for the presence of anti-CLAbs and antibodies against beta2-glycoprotein I (beta2-GPI), which is the most important cofactor of the 'pathogenic' anti-CLAbs in APLS. IgG anti-CLAbs were determined by an in-house quantitative ELISA and anti-beta2-GPIAbs using a commercial ELISA kit.

RESULTS

21.3% of the HCV and 14% of the HBV patients tested positive for IgG anti-CLAbs (P < 0.0001 compared with healthy controls). Neither age, sex, certain epidemiologic and laboratory parameters nor the clinical status and the histologic findings were associated with anti-CLAbs detection in both diseases. 2.3% of the HCV (P < 0.05 compared with healthy controls) and 2% of the HBV patients tested positive for anti-beta2-GPIAbs. Presence of anti-CLAbs was not associated with features of APLS.

CONCLUSIONS

A significant proportion of the HCV and HBV patients had detectable IgG anti-CLAbs. However, the anti-CLAbs titres were relatively low, and in most cases seem to be cofactor-independent ('nonpathogenic'). The latter is further supported by the lack of their association with clinical features of APLS. Furthermore, anti-CLAbs appear to be detected irrespective of the demographic, laboratory, clinical and histologic status in both HCV and HBV. However, prospective studies of longer duration may be required in order to address whether anti-CLAbs in patients with chronic viral hepatitis are or are not of clinical importance.

The antiphospholipid syndrome and infection

Infectious agents have been implicated in the induction of antiphospholipid (aPL) antibodies and the development of the antiphospholipid syndrome (APS). This review focuses on the types of aPL antibodies detected in infections and addresses whether these antibodies are of clinical importance in patients with infections. Hepatitis C virus (HCV) infection is given special attention because this virus has the propensity to induce various autoimmune phenomena. Several aspects are emphasized that should be considered carefully when interpreting results. Most of the published data agree that thrombophilia is not observed in patients with infections (including HCV) because aPL antibodies are mostly the natural or nonpathogenic type. Thus, we do not recommend routinely testing for HCV in patients with APS. However, not all infection-associated aPL antibodies are cofactor independent. For instance, infections are increasingly recognized as a major precipitating condition of the catastrophic variant of APS, perhaps via mechanisms of molecular mimicry. Therefore, it may be possible to prevent this devastating evolution if the infectious process is promptly recognized and exhaustively treated.

Cofactor dependence and isotype distribution of anticardiolipin antibodies in viral infections

BACKGROUND

Antibodies to cardiolipin (aCLs) are often detected in patients with autoimmune disorders or infectious diseases.

OBJECTIVE

To investigate the distribution of aCL isotypes and requirement of protein cofactor in viral infections in order to establish the importance, if any, of these antibodies in these infectious diseases.

PATIENTS AND METHODS

The isotype distribution of aCLs in the sera from 160 patients with infection caused by HIV-1 (n=40), hepatitis A virus (n=40), hepatitis B virus (n=40), or hepatitis C virus (n=40) was studied by standardised enzyme linked immunosorbent assay (ELISA) in the presence and absence of protein cofactor (mainly beta2-glycoprotein I). Serum samples from healthy volunteers and patients with syphilis and antiphospholipid syndrome were also included and served as negative and positive control groups respectively.

RESULTS

The prevalence of one or more aCL isotypes in serum of patients with HIV-1, hepatitis A virus, hepatitis B virus, or hepatitis C virus infection was 47%, 92%, 42%, and 17% respectively (principally IgM and/or IgA). Most of these antibodies were mainly cofactor independent.

CONCLUSIONS

The presence of aCLs in viral infections is principally cofactor independent, suggesting that cofactor dependence of the aCLs should be assessed to distinguish subjects most likely to suffer from clinical symptoms observed in the presence of these antibodies.

Lupus anticoagulant, anticardiolipin antibodies and hepatitis C virus infection in thalassaemia

Anticardiolipin antibodies (ACA) and lupus anticoagulant (LA) have been detected in patients with hepatitis C virus (HCV) infection and have been associated in autoimmune diseases (i.e. systemic lupus erythematosus) with an increased risk of thromboembolic events. Because of the high prevalence of HCV infection and the thrombotic risk described in thalassaemia we decided to investigate the prevalence of ACA and LA in a cohort of 68 thalassaemia patients. We found a high prevalence (34%) of beta2-glycoprotein I independent ACA in our thalassaemia patients which was related to HCV infection. None of patients developed any complications related to antiphospholipid antibodies (APL); therefore the clinical significance of positivity for APL in patients with HCV infection is at present unclear. In conclusion, the results of our study indicate that ACA in the serum of HCV-infected thalassaemic patients exhibit the characteristics of natural autoantibodies rather than those of the pathogenic autoantibodies that are found in patients with systemic lupus erythematosus.

Prevalence and significance of anticardiolipin, anti-beta2 glycoprotein I and anti-prothrombin antibodies in chronic hepatitis C

Antiphospholipid antibodies have been demonstrated in chronic hepatitis C, but their clinical and pathogenetic significance remains elusive. We prospectively studied 115 patients (85 men, mean age 36.9 years) with chronic hepatitis C without cirrhosis and treated by alpha-interferon (alpha-IFN). Antiphospholipid determinations comprised anticardiolipin (ACA), anti-beta2-glycoprotein I and anti-prothrombin antibodies of the IgG and IgM classes. At entry, 24 patients (21%) were found to possess low to moderate ACA levels (18 IgG, two IgM and four both isotypes) compared with only 4/115 age- and sex-matched control subjects (3.5% P=0.001). ACA positivity rate increased to 31% (P=0.01) after a 6-month course of alpha-IFN treatment. In contrast, the prevalence of anti-beta2-glycoprotein I and anti-prothrombin antibodies was not significantly different from controls at either time point. The presence of ACA correlated with that of antinuclear antibodies (P=0.0002), but was not associated with parameters such as histological activity, viral burden and response to alpha-IFN, nor with a history of thrombosis or pregnancy loss. However, a non-significant trend of higher incidence of mild thrombocytopenia among ACA-positive patients was observed. We conclude that low-titre ACA positivity is a common finding in patients with chronic hepatitis C, especially following alpha-IFN treatment, but does not select a category with different clinical features. These data are in keeping with the absence of associated anti-beta2GPI and anti-prothrombin antibodies, and do not support a role for HCV infection in the pathogenesis of the antiphospholipid syndrome.

Hepatitis C-associated autoimmune disorders

Hepatitis C virus (HCV) infection has been associated with multiple autoimmune manifestations. The immune response to HCV infection encompasses the development of autoantibodies, immune complex formation and deposition, and cryoglobulinemia complicated by vasculitis, glomerulonephritis, or neuropathy. HCV infection has been associated with antiphospholipid antibody syndrome, RA, SLE, PM/DM, and thyroid disease. HCV-infected patients also have a high incidence of sicca symptoms with sialoadenitis, and reports of low-grade lymphoproliferative malignancies have emerged. Optimal treatment for HCV-related autoimmune disease remains to be determined, but patients seem to respond to immunosuppression with classic agents or interferon.

Induction of anticardiolipin antibody and/or lupus anticoagulant in rabbits by immunization with lipoteichoic acid, lipopolysaccharide and lipid A

It still remains unclear how anti-phospholipid antibody develops in a specific patient group, however, it is possible that certain microorganism(s) may cause anti-cardiolipin antibody (aCL) development since aCL is frequently detected in patients with Treponema pallidum (TP) and/or other infectious diseases. Accordingly, we conducted an investigation to clarify whether or not anticardiolipin antibody (aCL) and/or lupus anticoagulant (LA) can be induced in rabbits by immunization with Gram-positive or -negative microorganism derivatives, such as lipoteichoic acid, lipopolysaccharide and lipid A. We detected the induction of SLE type-aCL (beta 2GPI-dependent) and LA in some rabbits immunized with lipid A and lipoteichoic acid, thereby suggesting that some microorganisms may contribute to even the production of pathogenic (SLE-type) antiphospholipid antibody.