HLA-DRB1 and -DQB1 alleles in the Brazilian population of the northeastern region of the state of São Paulo

The HLA-DRB1 and -DQB1 alleles in 161 healthy unrelated individuals, including Caucasians, Blacks and Mulattos (mixed Caucasian and Black), from the Northeastern region of the state of S?o Paulo, Brazil were analysed. The 36 different DRB1 alleles detected included not only common Caucasian alleles, but also DRB1*0411, 0807 and 1402, typical of Amerindians, and DRB1*0302, 1503, and 0804, typical of African American Blacks.     

Antinuclear antibodies testing as a routine screening for systemic lupus erythematosus in patients presenting first-episode psychosis

Aims: This report discusses the use of antinuclear antibody (ANA) detection as a screening test for neuropsychiatry systemic lupus erythematosus (NPSLE) in patients presenting a first‐episode psychosis. Methods: We reviewed the medical records of 85 patients admitted to an emergency service due to first‐episode psychosis, during a 1‐year period, for whom ANA detection was performed through an IFI HEp2 cell assay. ANA‐positive patients were subsequently evaluated for autoantibodies and neuroimaging exams. Results: Three patients presented as ANA positive in the initial screening and further investigation confirmed NPSLE in two patients. The patients were treated with antipsychotics and cyclophosphamide pulses with satisfactory outcomes. Conclusion: Even though ANA detection is not specific, it is a low‐cost procedure and could be an important screening test for NPSLE in the early‐onset psychosis.     

Lymphocytotoxic antibodies in systemic lupus erythematosus are associated with disease activity irrespective of the presence of neuropsychiatric manifestations

OBJECTIVES: To evaluate the association of the presence of lymphocytotoxic, anti-beta2-glycoprotein I (anti-beta2-GPI) and anti-ribosomal P (anti-P) antibodies in patients with systemic lupus erythematosus (SLE), presenting or not neuropsychiatric (NP) manifestations, stratified according to the activity of the disease. METHODS: A total of 138 patients with SLE (59 with active NPSLE, 49 with active non-NPSLE, and 30 with inactive disease) and 57 healthy controls were studied. Disease activity was assessed by the SLE Disease Activity Index (SLEDAI). The presence of lymphocytotoxic antibodies was assessed using a complement-dependent lymphocytotoxicity assay. The presence of anti-beta2-GPI and anti-P antibodies was detected by enzyme-linked immunosorbent assay (ELISA). RESULTS: Lymphocytotoxic antibodies were detected primarily in patients with active disease, that is in 35 out of 59 (59.3%) NPSLE and 23 out of 49 (46.9%) non-NPSLE patients, whereas only four out of 30 (13.3%) inactive SLE patients and none of the healthy controls exhibited the autoantibody. The frequency of lymphocytotoxic antibodies in active SLE patients, considered as a whole or stratified into NPSLE or non-NPSLE, was significantly increased in relation to inactive SLE patients (p<0.001 for each comparison). No significant difference was observed when comparing active NPSLE with non-NPSLE patients. No associations were observed between the presence of anti-beta2-GPI or anti-P antibodies and the activity of SLE or the presence of lymphocytotoxic antibodies. CONCLUSIONS: Lymphocytotoxic antibodies occurred more frequently in patients with active SLE than in patients with inactive disease, irrespective of the presence of NP manifestations, a finding that is similar to classical biomarkers of lupus activity (anti-dsDNA and complement). These results indicate that the assessment of the presence of lymphocytotoxic antibodies may be an additional useful tool for the evaluation of SLE activity.     

MRI assessment of bone marrow oedema in the sacroiliac joints of patients with spondyloarthritis: is the SPAIR T2w technique comparable to STIR?

Objective

To compare short tau inversion-recovery (STIR) with another fat saturation method in the assessment of sacroiliac joint inflammation.

Methods

This prospective cross-sectional study comprised 76 spondyloarthritis (SpA) patients who underwent magnetic resonance imaging of the sacroiliac joints in a 1.5-T scanner, using STIR, spectral attenuated inversion recovery (SPAIR) T2w and spectral presaturation with inversion recovery (SPIR) T1w post-contrast sequences.Two independent readers (R1 and R2) assessed the images using the Spondyloarthritis Research Consortium of Canada (SPARCC) score. We assessed agreement of the SPARCC scores for SPAIR T2w and STIR with that for T1 SPIR post-contrast (reference standard) using the St. Laurent coefficient. We evaluated each sequence using the concordance correlation coefficient (CCC).

Results

We observed a strong agreement between STIR and SPAIR T2w sequences. Lin’s CCC was 0.94 for R1 and 0.84 for R2 for STIR and 0.94 for R1 and 0.84 for R2 for SPAIR. The interobserver evaluation revealed a good CCC of 0.79 for SPAIR and 0.78 for STIR.

Conclusion

STIR technique and SPAIR T2w sequence showed high agreement in the evaluation of sacroiliac joint subchondral bone marrow oedema in patients with SpA. SPAIR T2w may be an alternative to the STIR sequence for this purpose.

Key points

? There are no studies evaluating which fat saturation technique should be used. ? SPAIR T2w may be an alternative to STIR for sacroiliac joint evaluation. ? The study will lead to changes in guidelines for spondyloarthritis.

     

Correlation between beta-2-glycoprotein I gene polymorphism and anti-beta-2 glycoprotein I antibodies in patients with multibacillary leprosy

Antiphospholipid antibodies, such as anti-β2-glycoprotein I (β2GPI), are present in multibacillary leprosy (MB) patients; however, MB patients do not usually present with antiphospholipid antibody syndrome (APS), which is characterized by thromboembolic phenomena (TEP). Rare cases of TEP occur in leprosy patients, but the physiopathology of this condition remains unclear. In this case–control study, we examined whether single-nucleotide polymorphisms (SNPs) of the β2GPI gene contributed to the risk of leprosy and APS co-morbidity. SNPs Ser88Asn, Leu247Val, Cys306Gly and Trp316Ser were identified in 113 Brazilian leprosy patients. Additionally, anti-β2GPI antibodies and plasma concentrations of β2GPI were quantified. The Ser88Asn, Cys306Gly and Trp316Ser SNPs were not risk factors for APS in leprosy. A higher frequency of Val/Val homozygosity was observed in leprosy patients compared to controls (36 vs. 5%; P < 0.001). Forty-two percent of MB and 17% of paucibacillary leprosy patients were positive for anti-β2GPI IgM (P = 0.014). There was no correlation between SNP Ser88Asn or Cys306Gly and anti-β2GPI antibody levels. In MB patients with positive anti-β2GPI IgM, the frequency of Val/Val homozygosity was higher than in controls (32 vs. 15%; P = 0.042). The frequency of the mutant allele Ser316 was higher in MB patients with positive rather than negative anti-β2GPI IgM levels (6 vs. 0%; P = 0.040) and was greater than in the control group (6 vs. 1%; P = 0.034). The studied polymorphisms did not influence the plasma concentrations of β2GPI. These results suggest that Leu247Val and Trp316Ser SNPs may represent genetic risk factors for anti-β2GPI antibody production in MB patients.     

Superoxide anion production by neutrophils is associated with prevalent clinical manifestations in systemic lupus erythematosus

To determine the relation between neutrophil function and the clinical characteristics of systemic lupus erythematosus (SLE), the superoxide anion () production by neutrophils, mediated by FcγR and FcγR/CR cooperation, was studied in 64 SLE patients classified according to their prevalent clinical manifestations. Three clinically distinct patterns were designated: (1) manifestations associated with the occurrence of cytotoxic antibodies (SLE-I group); (2) manifestations associated with circulating immune complexes (IC; SLE-II group), and (3) manifestations associated with IC and cytotoxic antibodies (SLE-III group). production was evaluated by a lucigenin-dependent chemiluminescent assay in neutrophils stimulated with IC-IgG opsonized or not with complement. No difference in production was observed when neutrophil responses from healthy controls were compared to the unclassified patients. However, when the SLE patient groups were considered, the following differences were observed: (1) SLE-I neutrophils showed lower production mediated by the IgG receptor (FcγR) with the cooperation of complement receptors (FcγR/CR) than observed in the SLE-II, SLE-III, and healthy groups; (2) neutrophils from the SLE-II group showed a decreased production mediated by FcγR/CR compared to the SLE-III group, (3) SLE-III neutrophils produced more than neutrophils from the SLE-II and control groups, and (4) CR showed inefficiency in mediating the production by neutrophils from the SLE-I group. Comparative experiments on the kinetics of chemiluminescence (CL; T _max and CL_max) disclosed differences only for the SLE-I group. Taken together, these results suggest that differences in oxidative metabolism of neutrophils mediated by FcγR/CR may reflect an acquired characteristic of disease associated with distinct clinical manifestations.     

Evolution of hepatitis C virus infection under host factor influence in an ethnically complex population.

BACKGROUND: The ethnic influence makes it difficult to reach a consensual definition of host-dependent genetic factors controlling the hepatitis C virus (HCV) disease course. Aims: To investigate, in an ethnically complex Brazilian population, whether human leucocyte antigen (HLA) molecules are associated with susceptibility to HCV infection, self-limiting viral clearance and predisposition to chronic disease. METHODS: One hundred and four HCV-antibody-positive patients (stratified into groups with spontaneous viral clearance and chronic HCV infection) and 166 healthy controls were submitted to HLA genotyping. RESULTS: Two strong associations were observed between the susceptibility to HCV infection and DRB3 [odds ratio (OR), 4.03; 95% confidence interval (CI), 2.40-6.77; P(c)=0.0000041] and DQB1*02 (OR, 1.72; 95% CI, 1.05-2.84; P=0.041), and between the spontaneous viral clearance and DRB1*01 (OR, 4.59; 95% CI, 1.70-12.41; P=0.003) and DQB1*03 (OR, 2.83; 95% CI, 1.14-7.02; P=0.029). No evidence was observed regarding the epidemiology or viral genotype influence on the disease course. CONCLUSION: We could confirm with a highly admixed population the association of viral clearance with two allele groups (DRB1*01 and DQB1*03) previously reported in homogeneous populations. The identification of DRB1*01 and DQB1*03 involved with self-limiting hepatitis in different ethnic groups is a very important finding that will contribute to the current knowledge about HCV-host interaction and the development of therapeutic vaccines.