Incidence of tuberculosis infection in spondyloarthritis patients treated with biological and conventional disease-modifying anti-rheumatic drugs in an endemic area

Introduction: Registries of spondyloarthritis (SpA) patients' follow-up provided evidence that tumor necrosis factor inhibitors (TNFi) increase the incidence of active tuberculosis infection (TB). However, most of these registries are from low burden TB areas. Few studies evaluated the safety of biologic agents in TB endemic areas. This study compares the TB incidence rate (TB IR) in anti-TNF-naïve and anti-TNF-experienced subjects with SpA in a high TB incidence setting.Methods: In this retrospective cohort study, medical records from patients attending a SpA clinic during 13 years (2004 to 2016) in a university hospital were reviewed. The TB IR was calculated and expressed as number of events per 105 patients/year; the incidence rate ratio (IRR) associated with the use of TNFi was calculated.Results: A total of 277 patients, 173 anti-TNF-naïve and 104 anti-TNF-experienced subjects, were evaluated; 35.7% (N = 35) of patients who were prescribed an anti-TNF drug were diagnosed with latent tuberculosis infection (LTBI). Total follow-up time (person-years) was 1667.8 for anti-TNF-naïve and 394.9 for anti-TNF-experienced patients. TB IR (95% CI) was 299.8 (37.4-562.2) for anti-TNF naïve and 1012.9 (25.3-2000.5) for anti-TNF experienced subjects. The IRR associated with the use of TNFi was 10.4 (2.3- 47.9).Conclusions: In this high TB incidence setting, SpA patients exposed to anti-TNF therapy had a higher incidence of TB compared to anti-TNF-naïve subjects, although the TB incidence in the control group was significant.(AU)

Correlation between cellular expression of complement regulatory proteins with depletion and repopulation of B-lymphocytes in peripheral blood of patients with rheumatoid arthritis treated with rituximab / Correlação entre expressão celular de proteínas reguladoras do complemento com a depleção e repopulação de linfócitos B no sangue periférico de pacientes com artrite reumatoide tratada com rituximabe

Abstract Objectives: To correlate the basal expression of complement regulatory proteins (CRPs) CD55, CD59, CD35, and CD46 in B-lymphocytes from the peripheral blood of a cohort of 10 patients with rheumatoid arthritis (RA) initiating treatment with rituximab (RTX) with depletion and time repopulation of such cells. Methods: Ten patients with RA received two infusions of 1 g of RTX with an interval of 14 days. Immunophenotypic analysis for the detection of CD55, CD59, CD35, and CD46 on B-lymphocytes was carried out immediately before the first infusion. The population of B-lymphocytes was analyzed by means of basal CD19 expression and after 1, 2, and 6 months after the infusion of RTX, and then quarterly until clinical relapse. Depletion of B-lymphocytes in peripheral blood was defined as a CD19 expression <0.005 × 109/L. Results: Ten women with a median of 49 years and a baseline DAS28 = 5.6 were evaluated; 9 were seropositive for rheumatoid factor. Five patients showed a repopulation of B-lymphocytes after 2 months, and the other five after 6 months. There was a correlation between the basal expression of CD46 and the time of repopulation (correlation coefficient = −0.733, p = 0.0016). A similar trend was observed with CD35, but without statistical significance (correction coefficient = −0.522, p = 0.12). Conclusion: The increased CD46 expression was predictive of a faster repopulation of B-lymphocytes in patients treated with RTX. Studies involving a larger number of patients will be needed to confirm the utility of basal expression of CRPs as a predictor of clinical response.

Resumo Objetivos: Correlacionar a expressão basal das proteínas reguladoras do complemento (PRC) CD55, CD59, CD35 e CD46 nos linfócitos B do sangue periférico de uma coorte de 10 pacientes com artrite reumatoide (AR) iniciando tratamento com rituximabe (RTX) com a depleção e tempo de repopulação dessas células. Métodos: Dez pacientes com AR receberam duas infusões de 1 g de RTX com intervalo de 14 dias. Análises imunofenotípicas para detecção de CD55, CD59, CD35 e CD46 nos linfócitos B foram feitas imediatamente antes da primeira infusão. A população de linfócitos B foi analisada por meio da expressão de CD19 basal e após um, dois e seis meses após a infusão de RTX e então trimestralmente até a recaída clínica. Depleção de linfócitos B no sangue periférico foi definida como expressão de CD19 < 0,005 × 109/l. Resultados: Dez mulheres com mediana de 49 anos e DAS 28 basal de 5,6 foram avaliadas; nove eram soropositivas para o fator reumatoide. Cinco pacientes apresentaram repopulação de linfócitos B após dois meses e as outras cinco aos seis meses. Houve correlação entre a expressão basal de CD46 e o tempo de repopulação (coeficiente de correlação -0,733, p = 0,0016). Tendência semelhante foi observada com CD35, porém sem significância estatística (coeficiente de correção 0,522, p = 0,12). Conclusão: Expressão aumentada de CD46 foi preditora de repopulação mais rápida de linfócitos B em pacientes tratados com RTX. Estudos com um número maior de pacientes serão necessários para confirmar a utilidade da expressão basal das PRC como preditora de resposta clínica.