VI Brazilian consensus guidelines for detection of anti-cell autoantibodies on HEp-2 cells

BACKGROUND

The VI Brazilian Consensus on Autoantibodies against HEp-2 cells for determination of autoantibodies against cellular constituents on HEp-2 cells was held on September, 2019, in Fortaleza (CE, Brazil). The guidelines in this edition were formulated by the group of Brazilian experts discussing the classification of complex patterns, the classification of the nuclear discrete dots (few and multiple), the identification of the discrete fine speckled pattern (AC-4a) and improvements on the ANA report.

MAINBODY

Sixteen Brazilian researchers and experts from universities and clinical laboratories representing the various geographical regions of Brazil participated in the meeting. Four main topics were discussed: (1) How to classify patterns with fluorescence in more than one cell compartment considering three relevant categoris: composite patterns, mixed patterns and multiple patterns; (2) The splitting of the discrete nuclear dots pattern into the multiple discrete nuclear dots (AC-6) and few discrete nuclear dots (AC-7) patterns, respectively; (3) Inclusion of a novel nuclear pattern characterized by discrete fine speckled pattern highly associated with antibodies to SS-A/Ro60, classified as AC-4a. In addition, adjustments on the Brazilian Consensus nomenclature were implemented aiming to harmonize the designation of some patterns with the International Consensus on ANA Patterns (ICAP). Furthermore, the designations of the PCNA-like pattern (AC-13), CENP-F-like pattern (AC-14) and Topo I-like pattern (AC-29) were adjusted in accordance to ICAP. Finally, there was a recommendation for adjustment in the test report in order to address the status of nuclear envelope staining. For all topics, the aim was to establish specific guidelines for laboratories and clinicians. All recommendations were based on consensus among participants. All recommendations from the V Consensus were maintained and there was relevant progress in the BCA/HEp-2 guidelines and further harmonization with ICAP.

CONCLUSION

The VI BCA/HEp-2 edition was successful in establishing important recommendations regarding the classification of complex patterns, in supporting the identification of a novel pattern within the AC-4 group and in the harmonization process with the ICAP terminology.

Laboratory profile after mining dam breach: Brumadinho Health Project results

ABSTRACT Objective: To evaluate changes in selected laboratory tests in the population included in the Brumadinho Health Project, according to the exposure to the dam failure. Methods: Cross-sectional study carried out on representative sample of residents (≥12 years) in Brumadinho, Minas Gerais, including: 1) non-exposed; 2) directly affected by tailings sludge; 3) residents in mining area. The prevalence of abnormal results of blood count, total, HDL and LDL cholesterol, triglycerides, aspartate aminotransferase, alanine aminotransferase, creatinine, urea, estimate of glomerular filtration rate (eGFR) and high-sensitivity C-reactive protein (hs-CRP) were estimated. The Prevalence Ratios (PR) and 95% Confidence Intervals (95%CI) of having an abnormal laboratory finding were estimated using Generalized Linear Models with Poisson probability distribution. Crude and adjusted models were estimated for age range, gender, diabetes, body mass index, smoking, hypertension. Results: After adjusting, there was no difference in PR between the three populations for most tests, with the exception of the population residing in an area with mining activity and not directly affected by the mud, with a lower chance of having altered total cholesterol (PR: 0.84; 95%CI 0.74–0.95) and a higher chance of having altered HDL cholesterol (PR: 1.26; 95%CI 1.07–1.50), hs-CRP (PR: 1.19; 95%CI 1.04–1.37), and eGFR <60mL/min/1,73 m2 (PR: 1.51; 95%CI 1.05–2.19). Conclusion: No significant differences were found in the prevalence of biochemical and hematological alterations between the populations directly exposed and not exposed to tailings. Only the group residing in the mining area had a higher prevalence of alterations related dyslipidemia, renal disease, and inflammation.

Perfil laboratorial após rompimento de barragem de mineração: resultados do Projeto Saúde Brumadinho

RESUMO Objetivo: Avaliar alterações em parâmetros laboratoriais na população do Projeto Saúde Brumadinho, segundo exposição ao rompimento da barragem. Métodos: Estudo transversal realizado em amostra representativa de residentes (≥12 anos) em Brumadinho, Minas Gerais, incluindo: não expostos (grupo referência); diretamente atingidos pela lama de rejeitos; e residentes em área de mineração. Foram estimadas as prevalências de resultados alterados de hemograma, colesterol total, colesterol lipoproteína de alta densidade (HDL), colesterol lipoproteína de baixa densidade (LDL), triglicérides, aspartato aminotransferase, alanina aminotransferase, creatinina, ureia, estimativa da taxa de filtração glomerular (TFGe) e proteína C-reativa ultrassensível (PCRus). As razões de prevalência (RP) e os intervalos de confiança de 95% (IC95%) de ter o exame alterado foram estimados por meio de modelos lineares generalizados com distribuição de probabilidade Poisson. Estimaram-se modelos brutos e ajustados por faixa etária, sexo, diabetes, índice de massa corporal, tabagismo, hipertensão. Resultados: Após ajustes, não se observou diferença nas RP entre as populações estudadas para a maioria dos testes, com exceção da população residente em área com atividade de mineração e não diretamente atingida pela lama, com menor chance de ter colesterol total alterado (RP=0,84; IC95% 0,74–0,95) e maior chance de ter colesterol HDL (RP=1,26; IC95% 1,07–1,50) e PCRus (RP=1,19; IC95% 1,04–1,37) alterado e TFGe<60 mL/min/1,73 m2 (RP=1,51; IC95% 1,05–2,19). Conclusão: Não foram encontradas diferenças significativas na prevalência de alterações bioquímicas e hematológicas entre a população diretamente exposta aos rejeitos e a população não exposta. Apenas o grupo residente em área de mineração apresentou maior prevalência de alterações relacionadas com dislipidemia, disfunção renal e inflamação.

Correction to: V Brazilian consensus guidelines for detection of anti-cell autoantibodies on hep-2 cells

After publication of the original article [1], we were notified that there is a mistake in Fig. 2.

V Brazilian consensus guidelines for detection of anti-cell autoantibodies on hep-2 cells

BACKGROUND

The V Brazilian Consensus for determination of autoantibodies against cellular constituents on HEp-2 cells, held in Brasilia (DF, Brazil) on August 27, 2016, discussed the harmonization between the Brazilian Consensus on ANA (BCA) guidelines and the International Consensus on ANA Patterns (ICAP) recommendations ( www.anapatterns.org ). Initial guidelines were formulated by the group of Brazilian experts with the purpose of guiding and enabling Brazilian clinical laboratories to adopt recommendations and to provide a common standard for national and international consensuses.

MAINBODY

Twenty Brazilian researchers and experts from universities and clinical laboratories representing the various geographical regions of the country participated in the meeting. Three main topics were discussed, namely the harmonization between the BCA guidelines and latest recommendations of the ICAP initiative, the adjustment of the terminology and report on HEp-2 patterns, and a reassessment of quality assurance parameters. For the three topics, our aim was to establish specific guidelines. All recommendations were based on consensus among participants. There was concrete progress in the adjustment of the BCA guidelines to match the ICAP guidelines. To a certain extent, this derives from the fact that ICAP recommendations were largely based on the algorithm and recommendations of the IV Brazilian ANA Consensus, as consistently recognized in the ICAP publications and presentations. However, although there is great overlap between the two Consensuses, there are some point divergences. These specific items were individually and extensively discussed, and it was acknowledged that in several points ICAP improved recommendations previously issued by the Brazilian ANA Consensus and these changes were readily implemented. Regarding some specific topics, the BCA panel of experts felt that the previously issued recommendations remained relevant and possibly will require further discussion with ICAP. The term anti-cell antibodies was adopted as the recommended designation, recognizing that the assay addresses antibodies against antigens in the nucleus and in other cell compartments. However, the acronym ANA HEp-2 was maintained due to historical and regulatory reasons. It was also signalized that the latest trend in ICAP is to adopt the term Indirect Immunofluorescent Assay on HEp-2 cell substrate (HEp-2 IIFA). In addition, the quality assurance strategies previously presented were ratified and emphasized.

CONCLUSION

The V BCA edition was successful in establishing an overall harmonization with the ICAP recommendations for interpretation of the HEp-2 IIFA test, pinpointing the perspectives in filling the remaining gaps between both initiatives.

Diagnostic Evaluation of ELISA and Chemiluminescent Assays as Alternative Screening Tests to Indirect Immunofluorescence for the Detection of Antibodies to Cellular Antigens

OBJECTIVES

Detection of antinuclear antibodies (ANAs) plays an important role in the diagnosis of systemic autoimmune rheumatic disease (SARD). Our goal was to evaluate the diagnostic accuracy of three commercially available enzyme-linked immunosorbent assay (ELISA) kits and one chemiluminescent assay for ANA detection, using the clinical diagnostic as the reference standard.

METHODS

We evaluated serum samples from 143 patients with an established diagnosis of SARD (group 1), 166 patients with infectious diseases and other rheumatic diseases for which the ANA test is not useful in diagnosis (group 2), and 89 outpatients with suspicion of SARD (group 3).

RESULTS

The sensitivity for ANA HEp-2, calculated in group 1, was 87.4% and varied between 62.9% and 90.0% for other tests. The specificity for ANA HEp-2, calculated in group 2, was 72.3% and varied between 45.2% and 90.4% for other tests. In group 3, the negative predictive value for ANA Hep-2 was 92.5% and varied between 89.3% and 100% for other tests.

CONCLUSIONS

Some ELISA kits have comparable or superior diagnostic sensitivity to ANA HEp-2 and could be used as an alternative method for ANA screening, therefore allowing the immediate report of the results with fewer false negatives than ANA HEp-2. Owing to the lower specificity, ELISA-positive samples should be submitted to ANA HEp-2 for confirmation of results.

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.

Detection of anti-nuclear antibodies by indirect immunofluorescence on HEp-2 cells: setting the appropriate screening dilution for the diagnosis of autoimmune rheumatic diseases

OBJECTIVE

To establish the abnormal title and the appropriate screening dilution for ANA (antinuclear antibodies) test by indirect immunofluorescence on HEp-2 cells (ANA HEp-2).

METHODS

An analysis of ANA Hep-2 in serum samples from 126 healthy individuals was performed. The samples were screened at a dilution of 1:80, and those positive were diluted to the title of 1:5120. The abnormal title of ANA was defined as that corresponding to the 95th percentile of the test in this population. The sensitivity of the different titles of antinuclear antibodies was determined in a group of 136 patients with a diagnosis of autoimmune rheumatic disease, and the specificity was determined in a group of 118 patients with other rheumatic diseases. The optimal cutoff value of the test was determined by ROC curve analysis.

RESULTS

The frequency of ANA positivity in healthy subjects was 13.2%. There was no difference in the frequency of positive results according to gender or age. The abnormal title of ANA was defined as the dilution of 1:160. The 1:80 dilution had sensitivity of 87.7% and specificity of 67.8%, while the 1:160 dilution had sensitivity of 82% and specificity of 73.7%. By ROC curve analysis, a dilution of 1:160 corresponded to the optimal cutoff value.

CONCLUSION

The abnormal title and the optimal cutoff value of ANA HEp-2 in the population was 1:160. Therefore, the dilution of 1:160 is the optimal screening dilution, with better specificity but without significantly compromising the sensitivity of the diagnostic test.