SARS-CoV-2 infection, gut dysbiosis, and heterogeneous clinical results of hydroxychloroquine on COVID-19 therapy-Is there a link?

Clinical manifestations of the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can include gastrointestinal signals and symptoms. Individuals with previous clinical conditions that usually enroll gut dysbiosis have been identified as being at high risk to develop more severe infectious phenotypes. Actually, intestinal dysbiosis has been observed in infected patients and potentially linked to systemic hyperinflammation. These observations suggest that a previous gut dysbiosis may be aggravated by SARS-CoV-2 infection and related to progression of the coronavirus disease 2019 (COVID-19) into more severe stages. While COVID-19's pathophysiology is not fully understood, it seems relevant to consider the interactions of candidate therapeutic drugs with the host, gut microbiota, and SARS-CoV-2. Here we summarize scientific evidence supporting the potential relevance of these interactions and suggest that unfavorable clinical data on hydroxychloroquine administration in COVID-19 may have been influenced by the dose provided and its impact on gut dysbiosis. The proposition is based on preliminary data on gut microbiota composition from individuals with inactive systemic lupus erythematosus under exclusive continuous hydroxychloroquine treatment, displaying a direct correlation between drug doses and markers typically associated with gut dysbiosis.

Abatacept induced long-term non-progressive reduction in gamma-globulins and autoantibodies: dissociation from disease activity control.

OBJECTIVES: To evaluate long-term effects on gamma-globulins and autoantibodies of abatacept (ABA) versus tumor necrosis factor inhibitors (TNFi) in rheumatoid arthritis (RA) patients. METHOD: Eighteen RA patients undergoing abatacept (ABA-RA) and 18 age/sex-matched patients treated with TNFi (TNFi-RA) were compared regarding clinical data, total gamma-globulins (TGG), specific subtypes (IgG, IgM, IgA), free light chains (FLC), IgM/IgG rheumatoid factor (RF), anti-cyclic citrullinated peptide (anti-CCP3), and anti-mutated citrullinated vimentin (anti-MCV), assessed before and every 6 months, up to 24 months. EXCLUSION CRITERIA: previous abatacept/rituximab or low TGG (< 0.7 g/dL). RESULTS: At baseline, female sex (78 vs. 78%), age (55 vs. 53 years), DAS28 (5.73 vs. 5.67), TGG (1.4 vs. 1.35 g/dL), IgG (1168 vs. 1079 mg/dL), IgM (107 vs. 113 mg/dL), IgA (333 vs. 322 mg/dL), kappa (342 vs. 249 mg/dL), lambda (170 vs. 150 mg/dL), IgM-RF (76 vs. 53 UI), IgG-RF (63 vs. 25 UI), anti-CCP3 (216 vs. 189 UI), and anti-MCV (202 vs. 102 UI) were comparable in ABA-RA and TNFi-RA (p > 0.05). Similar disease activity improvement was observed in both groups. In ABA-RA, significant decreases (p < 0.05) were observed in TGG (1.4 vs. 1.05 g/dL), IgG (1168 vs. 997), IgA (333 vs. 278 mg/dL), kappa (342 vs. 257 mg/dL), lambda (170 vs. 144 mg/dL), IgM-RF (76 vs. 37 UI), IgG-RF (65 vs. 24 UI), anti-CCP3 (216 vs. 183 UI), and anti-MCV (202 vs. 60 UI) at 6 months, without further decreases. In contrast, TNFi-RA showed no decrease in any of such parameters. ABA-RA also had more often transient IgG levels under the lower limit of normality (66.7% vs. 33.3%, p = 0.046). No severe infection occurred. DAS28, ESR, and CRP correlated significantly to gamma-globulins and FLC at baseline (p < 0.05), but these correlations were longitudinally lost in ABA-RA, but not in TNFi-RA. CONCLUSION: ABA, but not TNFi, induces a safe, persistent, long-term, and non-progressive reduction in gamma-globulins and autoantibodies, including anti-MCV. This pattern is dissociated from disease activity control.Key Points• ABA induces a long-term and non-progressive reduction in gamma-globulins and FLC, which occurs regardless of disease activity control.• ABA-induced reduction in gamma-globulins and FLC promotes a dissociation of such parameters and disease activity.• The same pattern of reduction is observed in autoantibodies: IgM-RF, IgG-RF, anti-CCP3, and anti-MCV.• Low transient IgG can be observed in RA patients treated with ABA, but does not correlate to infection.

IV Brazilian guidelines for autoantibodies on HEp-2 cells.

OBJECTIVE: The Fourth Brazilian Consensus for Autoantibodies Screening in HEp-2 Cells (ANA) was held in Vitória, Espírito Santo, and aimed to discuss strategies and recommendations about the technique, standardization, interpretation and quality control of the indirect immunofluorescence reaction on HEp-2 cells. METHODS: Twenty three ANA experts from university centers and private laboratories in different areas from Brazil discussed and agreed upon recommendations for the fourth edition of the Brazilian Consensus for Autoantibodies Screening in HEp-2 Cells. RESULTS AND CONCLUSION: The 4th ANA Consensus included three novel patterns into the existing algorithm (cytoplasmic Rods and Rings, nuclear Quasi-homogeneous, and CENP-F). Emphasis was given to the need of attention in describing the peculiar mixed pattern elicited by anti-DNA topoisomerase I (Scl-70) autoantibodies, comprising nuclear fine specked, nucleolar homogeneous pattern, NOR staining in metaphase plates, and cytoplasmic fine speckled patterns. The group also emphasized the need for continuous quality control in indirect immunofluorescence assays, the establishment of screening dilutions, as well as conjugate titration. An alert was made regarding the heterogeneity of commercial kits in defining patterns and the use of solid phase methodologies to determine the presence of autoantibodies.

IV Consenso Brasileiro para pesquisa de autoanticorpos em celulas HEp-2 / IV Brazilian Guidelines for autoantibodies on HEp-2 cells

Objetivo: O IV Consenso Brasileiro para Pesquisa de Autoanticorpos em Células HEp-2 (FAN) realizado em Vitória (ES), no dia 18 de setembro de 2012, objetivou discutir estratégias e recomendações relacionadas ao procedimento técnico, à padronização e à interpretação dos resultados da pesquisa de autoanticorpos em células HEp-2. Métodos: Participaram do evento 23 pesquisadores e especialistas de Universidades e laboratórios brasileiros. Foram abordados diferentes tópicos, discutidos amplamente a fim de se estabelecer recomendações específicas. Resultados e conclusão: O IV Consenso integrou à árvore de decisão o padrão citoplasmático em Anéis e Bastões, o padrão nuclear pontilhado Quasi-homogêneo (QH) e o padrão misto CENP-F. Discutiu-se ainda a necessidade de atenção para a classificação do padrão misto relacionado à presença de anticorpos anti-DNA topoisomerase I (Scl70), compreendendo os componentes nuclear pontilhado fino, nucleolar homogêneo, NOR na placa metafásica e citoplasmático pontilhado fino. Foram sugeridas diretrizes para o controle de qualidade do teste, diluição de triagem e diluição de esgotamento, e foi emitido alerta quanto à necessidade de atenção em relação à heterogeneidade de substratos disponíveis no mercado e a utilização de metodologias automatizadas para detecção de autoanticorpos. .

Objective: The Fourth Brazilian Consensus for Autoantibodies Screening in HEp-2 Cells (ANA) was held in Vitória, Espírito Santo, and aimed to discuss strategies and recommendations about the technique, standardization, interpretation and quality control of the indirect immunofluorescence reaction on HEp-2 cells. Methods: Twenty three ANA experts from university centers and private laboratories in different areas from Brazil discussed and agreed upon recommendations for the fourth edition of the Brazilian Consensus for Autoantibodies Screening in HEp-2 Cells. Results and conclusion: The 4th ANA Consensus included three novel patterns into the existing algorithm (cytoplasmic Rods and Rings, nuclear Quasi-homogeneous, and CENP-F). Emphasis was given to the need of attention in describing the peculiar mixed pattern elicited by anti-DNA topoisomerase I (Scl-70) autoantibodies, comprising nuclear fine specked, nucleolar homogeneous pattern, NOR staining in metaphase plates, and cytoplasmic fine speckled patterns. The group also emphasized the need for continuous quality control in indirect immunofluorescence assays, the establishment of screening dilutions, as well as conjugate titration. An alert was made regarding the heterogeneity of commercial kits in defining patterns and the use of solid phase methodologies to determine the presence of autoantibodies. .

The clinical spectrum of antinuclear antibodies associated with the nuclear dense fine speckled immunofluorescence pattern.

OBJECTIVE: Autoantibodies to lens epithelium-derived growth factor (LEDGF) depict a distinctive nuclear dense fine speckled (DFS) pattern in the indirect immunofluorescence antinuclear antibody assay (IIF-ANA). Definition of the clinical spectrum associated with anti-LEDGF antibodies has been evolving over the last decade. We investigated the frequency, clinical spectrum, and immunologic specificity of the DFS pattern in a general clinical laboratory routine. METHODS. All serum samples entered for IIF-ANA determination within a 2 year period were examined for the DFS pattern. Positive samples with consistent clinical information were studied further by IIF with isotype-specific conjugate and immunoblot analysis. RESULTS: Among 13,641 ANA-positive samples, 5081 (37%) presented the DFS pattern. Within a 6 month nested period, there were 650 samples with DFS pattern, and consistent clinical data were available for 81 of these. DFS reactivity was mainly due to IgG. Most samples (86%) presented titer > or = 1/640. Eighty of the 81 DFS samples reacted with a 75 kDa band that comigrated with the band elicited by the standard anti-LEDGF serum. Antibodies that were affinity-purified from the 75 kDa band reproduced the DFS pattern on IIF-ANA. The clinical spectrum associated with DFS reactivity included autoimmune diseases (39%) and an array of nonautoimmune conditions (61%). Among the autoimmune patients, over half presented evidence of autoimmune thyroiditis. CONCLUSION: Anti-LEDGF/p75 antibodies are a common finding among ANA-positive individuals with no evidence of rheumatic autoimmune disease, and should be regarded as a low specificity finding even when in moderate or high titer.

I Consenso Nacional para Padronização dos Laudos de FAN HEp-2 / The first Brazilian Consensus for Standardization of ANA in HEp-2 Cells

A análise da presença de auto-anticorpos feita por imunofluorescência indireta em células HEp-2 constitui-se em um método de triagem escolhido na maioria dos laboratórios clínicos. A ausência de uma nomenclatura definida para a descrição dos laudos tem trazido problemas na utilização clínica do teste, pelas dificuldades no controle de qualidade e na padronização dos resultados, que, por sua vez, embora similares, recebiam denominações diferentes. O I Consenso Brasileiro para Padronização dos Laudos de FAN HEp-2 reuniu em agosto de 2000, em Goiânia, diversos especialistas de todo o Brasil. Esses emitiram pareceres em consenso para os distintos padrões: nucleares, nucleolares, citoplasmáticos e aparelho mitótico. Foram feitas recomendações sobre os critérios para a leitura de uma lâmina, bem como para relação entre a diluição de triagem e o sistema óptico utilizado