Antibodies against the donor antigen glutathione S-transferase T1 after renal transplantation.

The aim of the present study was to determine whether a kidney graft expressing the glutathione S-transferase T1 enzyme (GSTT1) could cause an alloimmune response in a recipient with the null GSTT1 genotype that was similar to that observed in liver transplant. We have found anti-GSTT1 antibodies in the sera of a number of patients and confirmed that only one of the four possible genetic combinations--positive donor/null receptor--could lead to the production of these antibodies. Nevertheless, the main finding of this study is that in kidney transplantation, this mismatch was not sufficient to trigger an immune reaction. Longer follow-up of the posttransplant evolution of the patients is required in order to clarify the contribution of the factors involved in this process.

Glutathione S-transferase T1 genetic mismatch is a risk factor for de novo immune hepatitis in liver transplantation.

Glutathione S-transferase T1 (GSTT1) is a drug metabolizing enzyme abundantly expressed in liver and kidney cells; it is encoded by a single gene that is absent in 20% of the Caucasian population. Our group found that some liver transplantation patients developed de novo immune hepatitis (IH) and that all of them had anti-GSTT1 antibodies. The main objective of this study was to analyze the influence of a GSTT1 mismatch between donor and recipient in the immune response and the outcome of the graft. We confirmed that only under one of the four possible genetic combinations (null recipient/positive donor) is an alloimmune response triggered with production of anti-GSTT1 antibodies. Therefore, we conclude that this genetic mismatch can be considered a risk factor for de novo IH.

Autoantibodies to transcriptional regulation proteins DEK and ALY in a patient with systemic lupus erythematosus.

A human cDNA expression library that was used to investigate the nature of autoantigens recognized by the serum from a patient with systemic lupus erythematosus revealed the presence of antibodies directed against two transcriptional regulation protein: DEK, a site-specific 45 kD DNA binding protein, likely involved in signal transduction and transcriptional regulation, and a novel 28 kD protein that showed a 94% homology with murine ALY, a nuclear protein that plays a role in regulating the activity of TCRalpha enhancer complex. Whereas autoantibodies directed to epitopes on DEK are commonly found in patients with pauciarticular onset juvenile rheumatoid arthritis, autoantibodies against ALY have not been described and their occurrence has led to the cloning of the cDNA sequence of the first member of the human ALY family.

Lack of suppressive antibody activity in sera from patients with active-phase autoimmune diseases.

To investigate the presence of a suppressive antibody activity in sera from patients with autoimmune diseases, the IgG autoreactivity in whole serum was compared to that of the IgG fraction purified by affinity chromatography on protein G-sepharose. Competitive inhibition assays on the binding to histone, dsDNA, RNP and thyroglobulin of the purified IgG fraction by the autologous IgM present in serum without IgG and depleted of <100 kD components (named IgM fraction) were also performed. The IgG reactivity to the autoantigens tested was considerably increased in the IgG fraction than in the whole serum drawn from a healthy control and from three SLE patients in an inactive-phase of disease. Addition of the IgM fraction to the autologous purified IgG resulted in a dose-dependent inhibition of IgG binding to the autoantigens tested. However, no differences were observed between the autoreactivity of the IgG in whole serum and that of the purified IgG fraction from active-phase SLE patients, or from two patients with autoimmune thyroiditis, and the autologous IgM fractions did not inhibit significantly binding to the autoantigens under study of the purified IgG fraction. Our findings support the concept that the IgG autoreactivity in physiological conditions is regulated by idiotypic interactions between IgG and IgM, and suggest that this regulation is broken in the active phase of autoimmune diseases and that clinical remission from SLE could be associated with the restoration of this control mechanism. Additionally, qualitative differences, such as polyreactivity or change of idiotype in the autoreactive IgG fraction from active-phase disease might contribute to escape of regulation.

High seroprevalence of Pneumocystis infection in Spanish children.

Pneumocystis infection occurs worldwide, and most individuals test seropositive for Pneumocystis early in childhood. Little is known about the epidemiology of this infection in western Europe. The seroprevalence of Pneumocystis infection in 233 Spanish children was determined in a community study by immunoblot analysis of sera. The overall seroprevalence was 73%, with an age-related increase from 52% at 6 years to 66% at 10 years and 80% at 13 years. The data indicated a high seroprevalence of Pneumocystis infection in healthy Spanish children, thereby demonstrating that this pathogen is widespread in southern Spain.

Autoimmune deafness is not related to hyperreactivity to type II collagen.

The pathogenic role of anti-type II collagen was analysed in a variety of hearing losses, in age-matched controls and in different autoimmune diseases. The immune reactivity of peripheral blood lymphocytes to type II collagen was studied by the degree of proliferation measured as the incorporation of bromodeoxyuridine in cultured lymphocytes. The anti-type II collagen antibodies showed a very low incidence in the hearing loss group. Lymphocytes of otosclerosis, Meniere's disease and other sensorineural deafness patients proliferated in response to concanavalin A and to type II collagen to a lower extent than peripheral blood lymphocytes from healthy controls. Nonetheless, these differences were not statistically significant. The immune hyperreactivity to type II collagen cannot explain the autoimmune mechanism of hearing losses. Humoral and cellular hyperreactivities to inner ear proteins different from type II collagen, could explain the autoimmune mechanism of deafness.

[Serum and immunological markers of progression to acquired immunodeficiency syndrome in hemophiliacs]. / Marcadores séricos e inmunológicos de progresión a síndrome de inmunodeficiencia adquirida en hemofílicos.

In a cohort of 30 randomly selected hemophiliacs who were prospectively controlled for four years the predictive value of AIDS development was evaluated for serum markers of HIV infection and for lymphocytic subpopulations in peripheral blood. The patients were evaluated with a mean of 15.79 +/- 5.74 months, and overall antibodies, specific antibodies (anti-ENV and anti-p24), HIV antigen (Ag HIV) and lymphocyte subpopulations were determined. 50% of the hemophiliacs with positive serum Ag HIV (2/4) developed AIDS during the study, whereas this progression was not recorded in any anti-HIV positive, nonantigenic patient. The presence of Ag-HIV was detected at least two years before the diagnosis in these patients, and it was associated with the absence of anti-p24 in one or more determinations. The immune regulation parameters were not significantly different, at the beginning of the study, in the hemophiliacs who developed AIDS and in those who did not. However, the progression to AIDS was associated with a significantly smaller T4/T8 ratio at least one year before the diagnosis. Our results show that the development of AIDS in hemophiliacs is associated both with the presence of Ag-HIV in the serum and a reduction in the T4/T8 ratio, although the detection of the former appears to be earlier than that of the latter in this risk group.

[Anti-Sp100 and anti-Gp210 in the diagnosis of primary biliary cirrhosis in patients with autoimmune cholangitis]. / Anti-Sp100 y anti-Gp210 en el diagnóstico de cirrosis biliar primaria en pacientes con colangitis autoinmune.

We describe 2 women with features of autoimmune cholangitis. Serum biochemical studies showed cholestasis and increased immunoglobulin M with negative antimitochondrial antibodies. Markers of hepatitis B and C viruses were absent. Both had positive antinuclear antibodies. One had a speckled pattern (multiple nuclear dots) and the other a perinuclear pattern (pore nuclear). In the first case anti-Sp100 was positive by EIA and in the second anti-Gp210 was detected by immunoblot. Diagnosis of primary biliary cirrhosis was made and the patients were treated with UDCA. Current knowledge indicates that determination of anti-Sp100 and anti-Gp210 substantially improves diagnosis of primary biliary cirrhosis as these ANA are highly specific for this disease. These autoantibodies may lead to the classification of different groups of patient included in autoimmune cholangitis. All patients with autoimmune cholangitis should be tested for anti-Sp100 and anti-Gp210.

[Iliopsoas abscess and systemic lupus erythematosus]. / Absceso del músculo iliopsoas y lupus eritematoso sistémico.

Iliopsoas muscle abscess (IPA) is an uncommon condition, and it is usually associated with immunosuppression. Three out of a cohort of 552 patients diagnosed of systemic lupus erythematosus (SLE) developing an IPA, are reported herein. Patients showed fever and other symptoms related to SLE. They improved only partially under SLE therapy, and showed pain suggestive of IPA. It was confirmed by CT in all cases. S. aureus was isolated in one patient (primary IPA), and M. tuberculosis in the others. Specific antimicrobial therapy and surgical drainage were required. In summary, SLE might be considered as a risk condition for the development of IPA, due to the immunosuppression inherent in the disease and its treatment.

A recent onset inflammatory polyarthritis register in Spain: factors that predict remission.

OBJECTIVE: To identify baseline variables that predict remission at 1 year in patients with recent onset inflammatory polyarthritis (IP). METHODS: We prospectively studied 167 patients aged >or=16 years with a 4-week to 12-month history of swelling of >or=2 joints. At baseline, no patient had previously received corticosteroids or disease-modifying anti-rheumatic drugs (DMARDs). To adjust for differences in baseline variables associated with the type of treatment given (a surrogate marker of disease severity), we used regression analysis. The classification probability of treatment thus obtained was entered, along with other significant baseline variables, in a second separate regression analysis to identify variables that predicted remission (no swollen joints). RESULTS: Frequency of remission was 50.9% at 1 year. In the first regression analysis, variables associated with treatment with DMARDs or DMARDs and corticosteroids versus corticosteroids alone included age, morning stiffness, swollen joint count (SJC), disease severity according to the patient, and rheumatoid factor (RF) level; the strongest association was for higher SJC. In the second regression analysis, the model that best predicted remission (correct in 70.1% of cases) included age, tender joint count (TJC), erythrocyte sedimentation rate (ESR), RF, total Sharp score, disease severity according to the physician, and the 1987 American Rheumatism Association (ARA) criteria for rheumatoid arthritis (RA); the strongest association was for failure to meet these criteria. The model's sensitivity, specificity, and area under the receiver operating characteristic (ROC) curve were 70.6%, 70.9%, and 75.4%, respectively. CONCLUSION: Although we identified some predictors of remission, no model accurately predicted remission at 1 year in this cohort.

Anti-centromere antibodies in patients with systemic lupus erythematosus.

BACKGROUND: Anti-centromere autoantibodies (ACA) are frequently detected in systemic sclerosis (SScl), especially in the calcinosis, Raynaud phenomenon, esophageal dysmotility, sclerodactyly, telangiectasia (CREST) syndrome, in which a prevalence of 55% has been reported. The presence of ACA in systemic lupus erythematosus (SLE) is so rare that its detection can raise serious doubts about the validity of the diagnosis. OBJECTIVE: To determine the frequency of ACA positive subjects from a wide monocentric cohort of SLE patients and analyse the clinical and biological characteristics of this group. METHODS: Five hundred and sixty consecutive SLE patients were systematically analysed for the presence of ACA and other autoantibodies using indirect immunofluorescence, counter-immunoelectrophoresis, double immunodiffusion, enzyme-linked immunosorbent assay (ELISA), and Western-blot. RESULTS: ACA were detected in 11 SLE patients (1.9%); all of them were women. The CENP-B-specific ELISA was positive in all patients. The main clinical features of scleroderma (cutaneous sclerosis, sclerodactylia, digital ulcers, or pulmonary fibrosis) were not present in these patients, who did not differ clinically from the whole SLE group. CONCLUSIONS: ACA can be detected in patients with genuine SLE without concurrent scleroderma. Therefore, the presence of this antibody does not preclude the possibility of the diagnosis of SLE. In addition, SLE patients with ACA do not represent a different clinical subgroup.

Cytoplasmic detection of a novel protein containing a nuclear localization sequence by human autoantibodies.

A great diversity of antibodies directed to cell proteins has been described in sera of patients with autoimmune diseases. Most of these sera recognize nuclear components, but some others are directed against cytoplasmic autoantigens. Some of the antibodies directed to cytoplasmic autoantigens are well characterized, such as anti-mitochrondial, anti-ribosomal, anti-microsomal and anti-Golgi complex autoantibodies, but the target of many others remains unknown. In the last 5 years we have selected 32 sera with a characteristic speckled cytoplasmic pattern in indirect immunofluorescence (IIF) assay among a total of more than 31,000 sera from patients with any kind of autoimmune manifestation who attend our Connective Tissue Disease Clinic. Using a human cDNA expression library, we have identified a new autoantibody specificity named RCD-8 in five of these sera, directed to one cytoplasmic autoantigen. Affinity-purified antibodies eluted from a positive clone reproduced the same IIF cytoplasmic staining pattern as native serum and reacted with one single band of 160 kD on an immunoblot of HeLa cell extract. The sequence was found homologous to an autoantigen recently reported named Ge-1, and contains a nuclear localization sequence (NLS), an active protein domain made by a contiguous stretch of amino acids which allows the selective entry of the protein into the nucleus. The five patients whose sera exhibited this new autoantibody specificity displayed different autoimmune pathological profiles.

Antibodies to the AIDS-associated retrovirus in hemophiliacs and other individuals from southern Spain: lack of correlation with lymphocytes sub-populations.

Exposure to the AIDS-associated retrovirus (ARV) has been observed in 54 hemophiliacs in Southern Spain who have received commercial coagulation factors manufactured in the United States. Contact with ARV could be detected in some sera collected in 1982. Frequency among asymptomatic hemophiliacs was 44%, in individuals with lymphadenopathy syndrome 71%, and 2 AIDS cases were seropositive. Evidence for exposure to ARV did not correlate with changes in the lymphocyte populations or in the clinical condition of the patients. Only the amount of factor received distinguished the seropositive and the seronegative groups of hemophiliacs. Exposure to ARV was also detected in sera from homosexual men and I.V. drug addicts. The results indicate that members of AIDS risk groups in Spain have had contact with the AIDS retrovirus.

Presence of antibodies to different subunits of replication protein A in autoimmune sera.

A human cDNA expression library was used to investigate the nature of molecules recognized by serum from a patient with Sjögren syndrome that exhibits a mixed immunofluorescence pattern and reacts with multiple components on an immunoblot. The data demonstrated that this serum contains IgG antibodies specific for the 70- and 32-kDa subunits of replication protein A (RPA; RPA-70 and RPA-32, respectively), a highly conserved multisubunit DNA binding protein. Affinity purification of serum autoantibodies demonstrated a complete lack of cross-reactivity between RPA-70 and RPA-32, suggesting a direct participation of the native protein complex in the autoimmune response in this patient. Purified anti-RPA-70 and anti-RPA-32 antibodies labeled nuclear and cytoplasmic components in an immunofluorescence assay, suggesting that RPA is present in both cellular compartments. Additional sera from 55 patients with different autoimmune conditions were screened against purified RPA-70 and RPA-32 recombinant proteins. One of these 55 sera was positive and reacted with only RPA-32. Twenty sera from healthy control individuals did not react with RPA. These results show that RPA is a target for autoantibodies in human autoimmune diseases, although its precise frequency, occurrence in other autoimmune diseases, and pathological significance remain to be fully elucidated.

Multiple clinical and biological autoimmune manifestations in 50 workers after occupational exposure to silica.

OBJECTIVES: A self referred group of four workers from a factory producing scouring powder with a high silica content showed a surprisingly high number of features compatible with a connective tissue disease. Further subjects working at the same factory were subsequently studied to evaluate the relation between this exposure and the development of autoimmune processes. METHODS: A total of 50 subjects (44 women, six men; mean (SD) age 43.7 (5.5) years; mean duration of employment 6.1 years) underwent a prospective study including clinical history and physical examination, an immunobiological study, HLA typing, radiological and functional oesophageal and respiratory examination, ophthalmological examination, and isotopic testing of salivary glands. RESULTS: Symptoms of a systemic illness were present in 32 (64%) subjects: six with Sjögren's syndrome; five with the criteria for systemic sclerosis; three with systemic lupus erythematosus (SLE); five with an 'overlap syndrome'; and 13 with undifferentiated findings not meeting the criteria for a defined disease. Antinuclear antibodies were present in 36 (72%) subjects; four had antibodies to native DNA, including two subjects with SLE, one with systemic sclerosis associated with secondary Sjögren's syndrome, and one with overlap syndrome. Anticentromere antibodies were not detected. The frequency of HLA-DR3 was increased in the clinically affected subjects, but did not reach statistical significance. CONCLUSIONS: This descriptive study emphasises the high probability of workers occupationally exposed to silica developing a multiple spectrum of clinical and serological autoimmune manifestations.