Spontaneous inflammatory arthritis in HLA-B27 transgenic mice lacking beta 2-microglobulin: a model of human spondyloarthropathies.

Human class I major histocompatibility complex allele HLA-B27 is associated with a group of human diseases called "spondyloarthropathies." Studies on transgenic rats expressing HLA-B27 and human beta 2-microglobulin have confirmed the role of HLA-B27 in disease pathogenesis. Here we report spontaneous inflammatory arthritis in HLA-B27 transgenic mice lacking beta 2-microglobulin (B27+ beta 2m-/-). In the absence of beta 2-microglobulin, B27+ beta 2m-/- animals do not express the HLA-B27 transgene on the cell surface and have a very low level of CD8+ T cells. Most of the B27+ beta 2m-/- male mice showed nail changes, hair loss, and swelling in paws, which leads to ankylosis. The symptoms occur only after the B27+ beta 2m-/- mice are transferred from the specific pathogen-free mouse colony. These results suggest that aberrant assembly, transport, and expression of the HLA-B27 molecule may predispose an individual for development of the disease when exposed to an appropriate environmental trigger.

TACI is a TRAF-interacting receptor for TALL-1, a tumor necrosis factor family member involved in B cell regulation.

We and others recently reported tumor necrosis factor (TNF) and apoptosis ligand-related leukocyte-expressed ligand 1 (TALL-1) as a novel member of the TNF ligand family that is functionally involved in B cell proliferation. Transgenic mice overexpressing TALL-1 have severe B cell hyperplasia and lupus-like autoimmune disease. Here, we describe expression cloning of a cell surface receptor for TALL-1 from a human Burkitt's lymphoma RAJI cell library. The cloned receptor is identical to the previously reported TNF receptor (TNFR) homologue transmembrane activator and calcium modulator and cyclophilin ligand (CAML) interactor (TACI). Murine TACI was subsequently isolated from the mouse B lymphoma A20 cells. Human and murine TACI share 54% identity overall. Human TACI exhibits high binding affinities to both human and murine TALL-1. Soluble TACI extracellular domain protein specifically blocks TALL-1-mediated B cell proliferation without affecting CD40- or lipopolysaccharide-mediated B cell proliferation in vitro. In addition, when injected into mice, soluble TACI inhibits antibody production to both T cell-dependent and -independent antigens. By yeast two-hybrid screening of a B cell library with TACI intracellular domain, we identified that, like many other TNFR family members, TACI intracellular domain interacts with TNFR-associated factor (TRAF)2, 5, and 6. Correspondingly, TACI activation in a B cell line results in nuclear factor kappaB and c-Jun NH(2)-terminal kinase activation. The identification and characterization of the receptor for TALL-1 provides useful information for the development of a treatment for B cell-mediated autoimmune diseases such as systemic lupus erythematosus.

HLA-B27 heavy chains contribute to spontaneous inflammatory disease in B27/human beta2-microglobulin (beta2m) double transgenic mice with disrupted mouse beta2m.

MHC class I allele, HLA-B27, is strongly associated with a group of human diseases called spondyloarthropathies. Some of these diseases have an onset after an enteric or genitourinary infection. In the present study, we describe spontaneous disease in HLA-B27 transgenic mice where endogenous beta2-microglobulin (beta2m) gene was replaced with transgenic human beta2m gene. These mice showed cell surface expression of HLA-B27 similar to that of human peripheral blood mononuclear cells. In addition, free heavy chains (HCs) of HLA-B27 were also expressed on thymic epithelium and on a subpopulation of B27-expressing PBLs. These mice developed spontaneous arthritis and nail changes in the rear paws. Arthritis occurred primarily in male animals and only when mice were transferred from the pathogen-free barrier facility to the conventional area. Transgenic mice expressing HLA-B27 with mouse beta2m have undetectable levels of free HCs on the cell surface and do not develop arthritis. In vivo treatment with anti-HC-specific antibody delayed the onset of disease. Our data demonstrate specific involvement of HLA-B27 'free' HCs in the disease process.

HIV serosurveillance among prostitutes and patients from a sexually transmitted diseases clinic in Delhi, India.

Screening of 701 prostitutes in Delhi for HIV antibodies by a competitive ELISA test and supplementary Western blot test showed that only one of them was infected. Of the 4,572 samples from the patients attending a sexually transmitted disease clinic in Delhi, none showed evidence of HIV infection. In contrast to this low frequency of HIV infection in Delhi, a much higher frequency has been reported to the Indian Council of Medical Research from major metropolitan centers on the coast of India, namely, Bombay and Madras and their surrounding areas. It is possible that the infection is making inroads from these coastal areas to the interior of the country.

Human immunodeficiency virus infection in the blood donors of Delhi, India.

In the present study, blood from paid and unpaid donors was screened for the presence of HIV infection using a competitive ELISA test. None of the 8,000 unpaid donors but 4 (0.23%) of the 1,700 paid donors showed evidence of HIV infection. All of these four ELISA-positive samples were confirmed by the Western blot test. The present study indicates that HIV infection has entered the group of paid donors in the Delhi metropolitan area. Careful donor screening, discouraging use of paid donors, and stringent screening of donated units of blood has become mandatory in India to prevent HIV transmission through blood and blood products.

PIP: In Delhi, India, researchers collected sera from 1700 paid blood donors between January-February 1989 and from 8000 voluntary blood donors between September 1, 1988-February 28, 1989. Laboratory personnel screened all the sera for HIV antibodies using a competitive ELISA test. Any samples found to be reactive were tested again using the ELISA technique. Laboratory personnel determined reactivity a 2nd time in 4 samples. They confirmed that these 4 samples were positive for HIV by the Western blot test. The 4 positive samples came from paid donors (.23%), while no positives occurred in the volunteer group. Characteristics of the paid donors included male, 50% unemployed, illiterate, and median age of 28 years. 95% of the volunteers were males. Also volunteers were generally literate and educated. 3 of the 4 HIV positive donors were daily-wage unskilled laborers who went from city to city seeking employment. To sustain themselves or support their families, they would donate their blood often. All 3 have had sex with prostitutes. The 4th donor could not be found. Even though the prevalence of HIV is low among prostitutes in INdia, they are the largest risk group and prevalence is climbing. Since paid blood donors are usually transient, they can spread HIV to prostitutes of other cities as well as to recipients of their donated blood. 2 possible targets of intervention include educating the public to not accept blood from professional blood donors since their blood is not tested for HIV and educating prostitutes on methods of prevention of HIV infection.

HLA-B27 transgenic mice are susceptible to collagen-induced arthritis: type II collagen as a potential target in human disease.

HLA-B27 is highly linked with a group of human diseases called spondyloarthropathies (SpA). Many of these disorders begin after an infection with an enterobacteria. The symptoms seen in patients with spondyloarthropathies are inflammatory pain in the spine and asymmetrical arthritis of lower limbs. Additional symptoms related to SpA include inflammation in the eyes, bowel, and skin. The autoantigen(s) in SpA are not known. Proteins such as collagen and proteoglycans have been thought to be potent autoantigens in arthritidis including B27-associated human diseases. Type II collagen is a common denominator among eyes and joints, affected tissues in B27-linked diseases. Moreover, a few reports indicated CII specific T cells and antibodies in patients with spondyloarthropathies. We and others have previously described development of spontaneous arthritis and nail disease in HLA-B27 transgenic animals. To determine whether CII may be a target antigen in the B27-linked diseases, B27 + m beta 2 m% (HLA-B27) transgenic mice lacking mouse beta 2m with and without human beta 2m) mice were immunized with type II collagen inside the barrier facility. Male HLA-B27 transgenic mice developed collagen-induced arthritis compared to transgene negative littermates or female counterparts. There was no difference in the incidence of arthritis in HLA-B27 transgenic mice with and without human beta 2m. Our data suggest that beta 2m free heavy chain of HLA-B27 may present soluble antigens such as type II collagen to trigger specific T cells contributing in the development of arthritis. Our data also suggest that CII may be a potential target antigen in the cartilage during the disease process.

Peptide binding alpha1alpha2 domain of HLA-B27 contributes to the disease pathogenesis in transgenic mice.

Human spondyloarthropathies are strongly associated with a major histocompatibility complex (MHC) class I allele, HLA-B27. HLA-B27 transgenic mice and rats demonstrate many features of these diseases further confirming the role of HLA-B27 in disease. Yet the exact role of this molecule in disease pathogenesis is not clearly understood. We have previously reported spontaneous arthritis and nail disease in HLA-B27 transgenic mice lacking beta2-microglobulin (B27+beta2m(o)). These observations along with binding studies of B27 derived peptides to HLA-B27 molecule itself led to two hypotheses: (i) HLA-B27 derived peptide as a source of autoantigen; and (ii) HLA-B27 functions as an antigen presenting molecule. In this report, we confirm spontaneous disease in transgenic mice expressing a hybrid B27 molecule with alpha1alpha2 domain of B27 and alpha3 domain of mouse H-2Kd. These mice developed spontaneous arthritis and nail disease when transferred from specific pathogen free barrier facility to the conventional area. Other control mice with MHC class I transgene (e.g., HLA-B7, HLA-Cw3, and H2-Dd) did not develop such disease. In a MHC reassembly assay, binding of similar peptides to both wild type and hybrid B27 molecules was observed. In addition, the hybrid B27 molecule lacks at least one of the 3 proposed peptides from the third hypervariable (HV3) region of HLA-B27. These data strongly suggest that HLA-B27 molecule is an antigen presenting molecule rather than a peptide donor in the disease pathogenesis.

Human leukocyte antigen-DRB1*1502 (DR2Dw12) transgene reduces incidence and severity of arthritis in mice.

A strong correlation exists between susceptibility to RA in humans and some DRB1 alleles of the MHC region, such as DRB1*0401 and DRB1*0101. Meanwhile, incidences of other DR specificities, such as DR2, DR5, or DR7 have often been found reduced among RA patients. Like RA, susceptibility to mouse CIA is influenced by the MHC class II loci. To analyze the effect of a DRB1 molecule associated with low incidence of RA on mouse CIA, a human DRB1*1502 (DR2Dw12) transgene was introduced into CIA-susceptible B10.RQB3 (H2Aq) mice. Transgene-positive DRB1*1502 mice showed a significant reduction in the incidence and severity of arthritis. Moreover, the clinical reduction of arthritis correlated with the T-cell proliferative response of B10.RQB3-DRB1*1502 mice against a self-derived DRB1 peptide from the third hypervariable region. Our results suggest that the DRB1*1502-mediated protection against CIA can be explained by the DRB1 molecule acting as a source of self-antigenic peptide which interferes with the T-cell response against immunodominant regions(s) of the arthritogenic type II collagen molecule. By analogy, a similar mechanism might play a critical role in influencing the class II-associated predisposition to RA.

Animal models of human leukocyte antigen B27-linked arthritides.

The major histocompatibility complex class I allele human leukocyte antigen (HLA) B27 is strongly associated with human spondyloarthropathies. To date, 12 subtypes of HLA-B27 are known and most of them are linked with human spondyloarthropathies in different ethnic populations. Although these subtypes differ from each other by a few amino acids, the have an identical B pocket in the base of the antigen-binding groove. Considering the structure of HLA-B27 subtypes and their peptide binding specificity, it is important to consider their role as antigen-presenting molecules. Many B27-linked diseases begin after an infection with an enterobacteria, suggesting a role for environmental antigens in addition to an HLA-B27 molecule. To delineate the role of infection, studies have been carried out in animal models of reactive arthritidis. More recently, transgenic animal models have been used to understand the handling of environmental antigens by HLA-B27 molecule. This article discusses some of these transgenic and nontransgenic animal models of human diseases.

HIV infection in Asian Indian patients with haemophilia & those who had multiple transfusions.

A total of 124 Indian patients with haemophilia and 185 multiple transfused patients with thalassaemia, haemoglobinopathies, patients on chronic haemodialysis and others were screened for HIV-1 infection by a commercially available competitive ELISA test and supplementary Western Blot (WB) test. The results showed that HIV-1 infection was mostly confined to the haemophiliacs where 15 (12.1%) were confirmed to be positive for HIV infection. All except one had received both foreign and Indian cryoprecipitate. However, one haemophilic seroconverted within 4 months of receiving a cryoprecipitate manufactured in India.

Effect of high dose intravenous pulse dexamethasone on lymphocyte phenotypes.

The lymphocyte phenotypes were enumerated in 10 patients with collagen diseases at 0 h, 4 h, 24 h and 7 days after a megadose (100 mg) iv pulse dexamethasone. A significant decrease in CD3 (from a mean of 2324.3/mm3 to 705.9/mm3) and CD4 (from a mean of 1642.6 to 317.6/mm3) cells was observed at 4 h, which recovered partially by 24 h (186.7 and 1226.3/mm3 respectively) and completely at 7 days (2496.1 and 1838.4/mm3). A transient decrease in CD8 cells at 4 h was also observed. There was no significant effect on B cells.

Intermittent intravenous pulse cyclophosphamide treatment in systemic lupus erythematosus.

To determine the efficacy and safety of intermittent intravenous pulse cyclophosphamide in patients of severe systemic lupus erythematosus (SLE), 50 patients having severe/refractory lupus nephritis, vasculitis or neuropsychiatric manifestations were treated with 3 weekly pulses of cyclophosphamide for 6 such pulses. This treatment was found to be associated with significant and sustained improvement during a 2 yr follow up with respect to the mean renal activity score, individual renal parameters (proteinuria, erythrocyturia, and serum creatinine levels), focal neurological manifestations, vasculitic lesions, antinuclear antibody titers, complement component C3, anti-dsDNA antibodies levels and ESR. There was a sustained decrease in the overall mean disease activity score, and the mean daily dose of prednisolone (pretreatment 32.62 mg daily to 3.75 mg daily after 24 months). There was a significant decline in the percentage and absolute B cell count after 7, 14 and 21 days of this treatment. Effect on other lymphocyte subsets (CD3+, CD4+ and CD8+) was not marked. Pulse cyclophosphamide could therefore be an effective and less toxic form of treatment in patients with SLE having severe lupus nephritis, focal neurological lesions or vasculitis.

Common variable immunodeficiency (CVID) in northern India.

Fourteen patients with common variable immunodeficiency (CVID) were studied. The common clinical manifestations were recurrent sore throat, sinusitis, respiratory infections, diarrhea, and malnutrition. All had low IgG, with normal cell-mediated immunity. Treatment with immunoglobulin and/or plasma was effective in most of them. There were no severe adverse events with the therapy.

Flow cytometric analysis of T4:T8 splenic cell during dengue virus infection of mice.

The present study was undertaken to investigate the effect of dengue type 2 virus (DV) and DV-induced cytokines (CF and CF2) on T lymphocyte subpopulations of spleen by flow cytometry. Following DV-ic inoculation in mice the percent number of CD4+ and CD8+ lymphocytes in the spleen was reduced, the peak reduction in both was observed on the 6th day post-inoculation (p.i.). Intravenous inoculation of CF or CF2 in mice also decreased the percent number of CD4+ as well as CD8+ T lymphocytes subpopulation in the spleen, the maximum reduction being observed at 1 and 2 hr, respectively. The reduction in T lymphocyte subpopulation by CF and CF2 was found to be dose dependent. Thus, the alterations of T lymphocyte subpopulations during DV infection are mediated via cytokines.

Pneumocystis carinii infection in patients of AIDS in India.

This is the first report of Pneumocystis carinii infection seen in patients with AIDS in India. Two of the three patients were of Indian origin while the third was an American tourist. This report indicates that the technical problem of demonstrating P carinii may be an important factor underlying the diagnosis of PCP.

Effect of D-penicillamine on lymphocyte subsets: correlation with clinical response in rheumatoid arthritis.

We studied the effects of D-penicillamine (DP) on the clinical response, immunoinflammatory parameters and the lymphocyte subsets in 46 patients with rheumatoid arthritis (RA). Patients were evaluated before the start of the drug and then at 3 and 9 months during the follow up. 38 of 46 (82.6%) patients could continue DP treatment for over 9 months, while in 8 the drug was withdrawn due to adverse effects. Improvement in the various disease activity indices of more than 50% (responders) was seen in 25 of 38 (65.8%) patients. Responders showed a significant decrease in the serum IgA and IgM at 9 months, and in IgM only at 3 months. The serum levels of C3 and C4 did not show any significant change. Serum levels of C-reactive protein and rheumatoid factor (RF) showed a significant decrease at 3 and 9 months. A significant decrease in CD3+ and CD4+ lymphocytes along with a fall in CD4+/CD8+ lymphocyte ratio was also seen in responders at 3 and 9 months, compared to the baseline. Our results suggest that DP may have immunomodulatory action in RA.

AIDS screening in North India: clinical spectrum of HIV infection.

PIP: 8 subjects with human immunodeficiency virus (HIV) infection were encountered between June-December 1986 and were diagnosed as having AIDS (3), PGL (1), MLA (1), and asymptomatic HIV carrier state (3). The clinical presentation, immunologic features, and course of those with AIDS or PGL, were similar to those reported from American, European, and tropical African countries, with low T-helper cells, reversed CD4/CD8 ratio, and the presence of antibody to HIV. Asymptomatic carriers also had reversed CD4/CD8 ratio. 6 of these individuals were foreign visitors, 5 from tropical African countries and 1 from the US, while 2 were Indians who had frequent sexual exposure abroad in countries where AIDS is quite prevalent (1 homosexual in West Germany and other possibly had sexual exposure in Uganda). None of the 2046 Indian nationals in the high risk group screened until January 1987 without history of sexual, blood, or blood product exposure abroad were found to seropositive at this center in North India. These findings suggest that HIV infection is not endemic in North India. However, there is a risk of spread of this infection in North India through sexual or blood contact with foreign visitors.^ieng

Acquired immunodeficiency syndrome (AIDS) in multitransfused children with thalassemia.

Two hundred and three multi-transfused children with thalassemia attending the Thalassemia Clinic of the Charak Palika Hospital, New Delhi were screened for human immunodeficiency virus (HIV) antibodies by ELISA and all positive cases were confirmed by Western Blot. Of the 203 children screened, 18 (8.9%) were HIV positive, and in these children a detailed immunological work up was done and compared to 18 age-matched HIV negative thalassemics as controls. The tests included absolute lymphocyte counts (ALC), absolute and percentages of CD4+ and CD8+ cells and their ratios (CD4/CD8), immunoglobulin levels (IgG, IgM and IgA) and delayed cutaneous hypersensitivity (DCH) test by Multitest CMI in all the cases and the controls. Of the 18 HIV positive children, 6 were diagnosed to have clinical AIDS as per the WHO criteria. After immunological testing, the children were further classified according to the CDC criteria. By these criteria, 11 children were classified as P1 A (asymptomatic infection, normal immune function), 1 child as P1 B (asymptomatic infection, abnormal immune function), 2 children as P2 A (symptomatic infection with non-specific findings), 1 child as P2 C (lymphocytic interstitial pneumonitis), 1 child as P2 D1 (Pneumocystis carinii pneumonia) and 2 children as P2 D2 (symptomatic infection with infections). In this paper, the clinical features of the children with AIDS is described, and the immunologic functions of these children are compared with the HIV positive asymptomatic children and with controls. These are the first cases of AIDS in the pediatric age group from India.

Acquired immunodeficiency syndrome (AIDS) with lymphocytic interstitial pneumonitis (LIP) in a multi transfused child with thalassemia major.

PIP: The case of a 10.5-year-old girl, who was diagnosed with a case of thalassemia major at the age of 8 months and had been on regular blood transfusions since then, is related. Donor screening for HIV was started in mid-1988, thus she had received unscreened blood for a number of years. In February 1991, she presented with a dry persistent cough, moderate grade continuous fever, and breathlessness on exertion for over 2 weeks. Chest X-ray showed bilateral infiltrations. She was put on penicillin and chloramphenicol with a provisional diagnosis of bronchopneumonia. In March 1991, she had to be hospitalized for impending respiratory failure. After treatment with intravenous fluids and parenteral antimicrobials, her condition stabilized and she was discharged. In April 1991, she was readmitted because of complaints of difficulty in swallowing and weight loss. Her chest signs had persisted and she had developed oropharyngeal candidiasis with ulcerations. She also had alopecia, a generalized lymphadenopathy, digital clubbing, and bilateral parotid enlargement. Candidiasis responded to vigorous therapy with clotrimazole. Fine needle aspiration of lymph node showed a reactive hyperplasia. HIV antibodies were detected in the serum with ELISA and confirmed by Western blot. Immunologic tests showed evidence of severe immunodeficiency. The Multitest CMI, which simultaneously tests delayed skin hypersensitivity to seven common recall antigens, was totally nonreactive. She was classified as having AIDS according to World Health Organization criteria for children under 13 years of age. The diagnosis of lymphocytic interstitial pneumonitis (LIP) was also made based on the symptoms. Oral prednisolone was given 2 mg/kg/day in 3 divided doses for a month. The cough and dyspnea showed great improvement and the parotid swellings disappeared; lymphadenopathy, clubbing, and alopecia, however, persisted. The child was kept on maintenance therapy of prednisolone and on alternate day co-trimoxazole for prophylaxis against Pneumocystis carinii infection.^ieng