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As the coronavirus disease 2019 (COVID-19) pandemic second wave is emerging, it is of the upmost importance to screen the population immunity in order to keep track of infected individuals. Consequently, immunoassays for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with high specificity and positive predictive values are needed to obtain an accurate epidemiological picture., As the coronavirus disease 2019 (COVID-19) pandemic second wave is emerging, it is of the upmost importance to screen the population immunity in order to keep track of infected individuals. Consequently, immunoassays for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with high specificity and positive predictive values are needed to obtain an accurate epidemiological picture. As more data accumulate about the immune responses and the kinetics of neutralizing-antibody (nAb) production in SARS-CoV-2-infected individuals, new applications are forecast for serological assays such as nAb activity prediction in convalescent-phase plasma from recovered patients. This multicenter study, involving six hospital centers, determined the baseline clinical performances, reproducibility, and nAb level correlations of 10 commercially available immunoassays. In addition, three lateral-flow chromatography assays were evaluated, as these devices can be used in logistically challenged areas. All assays were evaluated using the same patient panels in duplicate, thus enabling accurate comparison of the tests. Seven immunoassays examined in this study were shown to have excellent specificity (98 to 100%) and good to excellent positive predictive values (82 to 100%) when used in a low (5%)-seroprevalence setting. We observed sensitivities as low as 74% and as high as 95% at ≥15 days after symptom onset. The determination of optimized cutoff values through receiver operating characteristic (ROC) curve analyses had a significant impact on the diagnostic resolution of several enzyme immunoassays by increasing the sensitivity significantly without a large trade-off in specificity. We found that spike-based immunoassays seem to be better correlates of nAb activity. Finally, the results reported here will add to the general knowledge of the interlaboratory reproducibility of clinical performance parameters of immunoassays and provide new evidence about nAb activity prediction.

This study investigated the prevalence of TIL subpopulations, TLS, PD-1 and PD-L1 in tumors from TNBC patients harboring wild-type or mutated BRCA1 or BRCA2 germline genes. This TNBC cohort included 85% TIL-positive (≥10%) tumors with 21% classified as TILhi (≥50%). Interestingly, the BRCAmut group had a significantly higher incidence of TILpos tumors compared to the BRCAwt group (P = 0.037). T cells were dominant in the infiltrate but no statistically significant differences were detected between BRCAwt and BRCAmut for CD3+, CD4+ and CD8+ T cells or CD20+ B cells. TLS were detected in 74% of tumors but again no significant differences between the BRCA groups. PD-1 expression was observed in 33% and PD-L1 in 53% (any cell, cut-off ≥1%) tumors for the entire TNBC cohort. PD-1 expression correlated with PD-L1 and both with TIL and TLS but was not associated with BRCA mutational status. Our analyses reveal that BRCAwt and BRCAmut TNBC are similar except for a significant increase of TILpos tumors in the BRCAmut group. While BRCA gene mutations may not directly drive immune infiltration, the greater number of TILpos tumors could signal greater immunogenicity in this group.

Age at menarche shows a downward secular trend and differs according to socioeconomic conditions, presumably the result of dietary variations. We report two studies conducted in Quebec City in which the relation between diet and menarche was evaluated. In 1978-1980, baseline information for these studies was obtained on girls aged 9 through 15 and included body weight, height, fatfold thickness at six sites, percent of body fat (derived from underwater weighing), and a 3-day dietary record. In a cross-sectional study of 207 girls aged 11 through 15, we compared dietary patterns between premenarcheal and menarcheal girls using logistic regression. In a 6-year follow-up study of 109 girls who had not experienced menarche at the baseline data collection, the relation between time of occurrence of menarche and dietary patterns was assessed using proportional hazards models. The results confirm the association between body weight and age at menarche. Body fat, however, was not strongly related to the onset of menstruation. In both studies, a higher dietary energy intake was associated with an earlier age at menarche. Dietary composition, and dietary fat in particular, was not related to menarche.