Serum non-organ specific autoantibodies in human immunodeficiency virus 1 infection

Nonorgan-specific autoantibodies in HIV-infected patients in the HAART era

Nonorgan-specific autoantibodies (AAbs) are used for diagnosing autoimmune diseases but can also be detected in other conditions. We carried out a cross-sectional study with the aim to screen HIV1-infected patients in the era of highly active antiretroviral therapy (HAART) for AAbs and to analyze the association of their presence with hypergammaglobulinemia and immunovirological status.Blood samples from HIV1-infected patients without major concomitant illnesses followed in 2 hospitals in Paris, France were tested for immunovirological status, serum immunoglobulin G (IgG) level, antinuclear antibodies (ANAs), anti-double-stranded DNA (anti-dsDNA), anti-extractable nuclear antigens (anti-ENAs), anticardiolipin (aCL), anti-β2glycoprotein1 (anti-β2GP1), and antineutrophil cytoplasmic antibodies (ANCAs). Clinically relevant AAbs were defined as ANAs with titers ≥1:160, anti-dsDNA or anti-ENA antibodies; aCL or anti-β2GP1 antibodies with a level ≥40 U/ml; and ANCAs reacting with proteinase 3 or myeloperoxidase.We included 92 patients (mean age 47 years, men 55%, sub-Saharan African background 55%, HAART 85%, mean CD4 lymphocyte count 611/mm, viral load < 40 copies/mL 74%). At least 1 AAb was detected in 45% of patients, mostly ANAs (33%) and ANCAs (13%); 12% had ≥1 clinically relevant AAb. Above-normal IgG levels were found in 71% of patients. We found an inverse association between the presence of ≥1 AAb and CD4 lymphocyte count (P = 0.03) and between above-normal IgG levels and duration of virological control (P = 0.02) and non-sub-Saharan African background (P = 0.001).In sum, in HIV1-infected patients without any major concomitant illness in the HAART era, the prevalence of AAbs remains high but AAb patterns leading to high suspicion of autoimmune diseases are rather uncommon. AAb presence is associated with reduced CD4 lymphocyte count but not hypergammaglobulinemia.

Antigenic Complementarity Resulting in Idiotype–Antiidiotype Immune Complexes: Possible Contributor to AIDS Pathogenesis and Autoimmunity

One hundred and sixty seven combinations of viral + viral antibodies or viral + bacterial antibodies were tested for their ability to precipitate each other. Some antibodies produced against HIV epitopes recognize and precipitate some antibodies produced against cytomegalovirus (CMV), hepatitis B virus (HBV) core antigen, and Mycobacteria tuberculosis (MTb) and Staphylococcus epitopes but not those against HBV surface antigen, herpes simplex types 1 and 2 (HSV1 and HSV2) or Epstein-Barr virus (EBV), Streptococcus, or Escherichia coli. In addition, CMV antibodies precipitate those of HBV core and surface antigens as well as MTb, but not HSV, HSV2, EBV, Streptococcus or E. coli. HBV core (but not surface) antibodies precipitated Mycobacterium avium antibodies (MAv) but not MTb, Streptococcus, Staphylococcus or E. coli antibodies. Binding constants vary between kds of 10(-9) and 10(-7) M. Interactive antibodies act like idiotype-antiidiotype pairs suggesting that the inducing antigens are molecularly complementary. The resulting antibody interactions may explain the formation of circulating immune complexes that are commonly found in AIDS and in other diseases characterized by multiple, concurrent infections. This observation suggests that AIDS pathogenesis may involve autoimmune mechanisms in which the immune system attacks itself to form antibody-antibody circulating immune complexes that contribute to the hypergammaglobulinemia characteristic of AIDS. Complementary cofactor infections in AIDS may therefore contribute to the immunosuppression of the syndrome and difficulties treating these corresponding infections.

Human and Nonhuman Primate Lentiviral Infection and Autoimmunity

The goal of this communication is to summarize the following-the types of autoimmune responses that have been characterized in human HIV-1 infection; the potential mechanisms that were initially thought to be the basis for such autoimmune responses; the prevalence and incidence of conventional autoimmune diseases with HIV-1 infection; the spectrum of autoimmune disorders following the institution of HAART and its associated mechanisms; the role of such autoimmunity in SIV-infected nonhuman primates; and the molecular basis for autoimmune responses, such as the role of exosomes in lentiviral disease.

Antigenic complementarity among AIDS-associated infectious agents and molecular mimicry of lymphocyte proteins as inducers of lymphocytotoxic antibodies and circulating immune complexes

BACKGROUND

People at risk for acquired immunodeficiency syndrome (AIDS) have high rates of cofactor infections in addition to HIV, including cytomegalovirus, hepatitis viruses, Mycobacteria, Mycoplasmas, and Staphylococcus aureus. Most people with AIDS also develop lymphocytotoxic antibodies (LCTA) and circulating immune complexes (CIC). While HIV proteins mimic HLA antigens, many cofactor agents mimic CD4 antigens. It has therefore been proposed that cofactor infections may interact with HIV by producing complementary antigens that induce LCTA and CIC, and that the resulting immunological dysfunction is part of AIDS pathogenesis.

OBJECTIVES

To test (1) whether HIV and its cofactor infections elicit complementary (idiotype-anti-idiotype) antibodies, and (2) if any of these antibodies mimic anti-lymphocyte antibodies.

STUDY DESIGN

Two immunological methods are employed to test for antibody complementarity: (1) double antibody diffusion, a modification of Ouchterlony immunodiffusion, in which antibodies are tested for their ability to precipitate each other; (2) double-antibody ELISA, in which an antibody against one infectious agent is adsorbed to an ELISA plate and an antibody against a second agent is used to detect the first.

RESULTS

Data on over a thousand double antibody diffusion (DAD) and about 70 DA-ELISA experiments are reported. These show that only specific pairs of antibodies are complementary: HIV-CMV; HIV-HBV; HIV-tuberculosis; HIV-mycoplasmas; HIV-S. aureus; and CMV-mycoplasmas. In addition, HIV antibodies precipitate CD4 antibodies; CMV antibodies precipitate HLA-DR antibodies; while mycobacteria and mycoplasma antibodies precipitate macrophage antibodies.

CONCLUSIONS

Antibodies elicited by HIV infection can interact with antibodies elicited by cofactor infections to form CIC, and some of these antibodies mimic lymphocyte antibodies so that they may function as LCTA. Since LCTA and CIC are associated with increased lymphocyte death in AIDS, the immune response against cofactors in HIV may play a significant role in AIDS pathogenesis. The fact that both HIV and cofactors elicit antibodies with LCTA characteristics may pose problems for vaccine development.

Association of viral load in plasma samples of HIV-infected hemophilia patients with autoantibodies and gp120-containing immune complexes on CD4+ lymphocytes

OBJECTIVE

We investigated whether the induction of antilymphocyte autoantibodies and immune complexes is associated with the activity of HIV replication.

METHODS

Viral HIV-1 RNA was measured in the plasma samples of 84 HIV+ hemophilia patients and correlated with the IgM, IgG, IgM/IgG and IgM/IgG/gp120 load of circulating CD4+ lymphocytes, CD4+ and CD8+ cell counts, plasma neopterin levels and in vitro T-cell responses to mitogens and pooled allogeneic stimulator cells.

RESULTS

Compared to patients with no immune complexes, on circulating CD4+ lymphocytes, viral load was increased in patients with IgM, IgM/IgG or IgM/IgG/gp120 complexes. Sequential analysis of HIV+ patients showed that peaks of retroviral activity were associated with the subsequent formation of CD4+ lymphocyte-reactive IgM and IgG autoantibodies and gp120-containing immune complexes.

CONCLUSION

The induction of autoantibodies and immune complexes attached to CD4+ lymphocytes is associated with periods of increased viral activity in HIV-infected patients.

Anti-smooth muscle antibody in clinical human and experimental animal Mycoplasma pneumoniae infection

Autoantibody formation is possibly integral to the development of non-respiratory manifestations of acute Mycoplasma pneumoniae infection. We sought to confirm the occurrence of smooth muscle antibodies (SMA) in humans with acute Myc. pneumoniae respiratory infection and furthermore to assess whether similar autoantibodies would develop in a hamster model of respiratory infection. Paired sera from 21 patients with acute infection were assayed for SMA by immunofluorescence on mouse kidney/stomach substrates. The frequency of SMA was then determined for 52 paediatric patients with acute Myc. pneumoniae infection and 16 controls, and for sera from a hamster model of infection. Five of 21 paired sera had an increment in SMA between acute and convalescent specimens. At a screening dilution of 1:40, 18/52 infected and 0/16 controls had positive sera (P = 0.003); positive specimens demonstrated IgG rather than IgM SMA. In the hamster model of Myc. pneumoniae respiratory infection, significant IgG SMA increases occurred in 7/19 infections but not in 11 controls (P = 0.02). Immunoblotting did not identify actin as the substrate for SMA. Smooth muscle antibody increases are found in a significant minority of Myc. pneumoniae-infected humans and hamsters. A role for SMA in the pathogenesis of Myc. pneumoniae infection remains to be defined.

Varicella-zoster virus retrobulbar optic neuritis in a patient with human immunodeficiency virus

PURPOSE

To determine the cause of bilateral retrobulbar optic neuritis followed by progressive outer retinal necrosis in a patient with human immunodeficiency virus (HIV).

METHODS

Extensive ophthalmologic, neurologic, infectious disease, rheumatologic, and radiologic examinations were performed.

RESULTS

Cerebrospinal fluid samples taken after the onset of bilateral retrobulbar optic neuritis and before the development of clinical progressive outer retinal necrosis disclosed varicella-zoster virus from polymerase chain reaction and viral culture.

CONCLUSION

Ophthalmologists and neurologists should consider varicella-zoster virus optic neuritis as a potential precursor of progressive outer retinal necrosis and as a cause of retrobulbar optic neuritis in patients infected with HIV.

Cold urticaria and HIV infection

Three patients, all seropositive for HIV antibody, complained of swelling and pruritus on the head and limbs when exposed to the cold. All three had received zidovudine for significant CD4 cell depletion, but had no AIDS-defining illnesses. An ice-cube test was positive on each individual. There was no evidence of cold agglutinins, cryoglobulins, syphilis, or other concurrent diseases in any of the patients. This association may represent yet another allergic manifestation in HIV infection.

Autoantibodies in HIV-infected patients that modulate the cholinergic activity of heart and gut tissue

In human immune deficiency virus (HIV) disease, direct infection of heart tissue with HIV and repeated intestinal infections with opportunistic pathogens are thought to be the main cause of cardiac disease and diarrhoea respectively. A role for autoimmune phenomena may also be involved in the pathogeny of HIV disease. In this study, we demonstrate that immunoglobulins from the A and G classes from HIV positive patients are able to interfere with the function of the muscarinic cholinergic receptors from heart and gut. Both IgA and IgG HIV+ preparations decreased the tension of isolated atria and increased the tension of isolated ileum. The mechanical effect of carbachol was inhibited in both atria and ileum preparations, when they were preincubated with either IgA or IgG HIV+ fractions. An inhibitor of muscarinic cholinergic receptors (atropine) impaired the negative inotropic action of HIV+ immunoglobulins (Ig) on the heart and prevented the positive inotropic effect of HIV+ Igs on ileum. HIV+ IgA fraction was approximately ten fold more potent to interfere with the cholinergic function as compared to the IgG fraction. These results suggest that antibodies present in HIV+ serum may also modulate muscle's cholinergic activity in the heart and ileum from HIV+patients.