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.

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