RESUMEN
We report evaluation of 30 assays' (17 rapid tests (RDTs) and 13 automated/manual ELISA/CLIA assay (IAs)) clinical performances with 2594 sera collected from symptomatic patients with positive SARS-CoV-2 rRT-PCR on a respiratory sample, and 1996 pre-epidemic serum samples expected to be negative. Only 4 RDT and 3 IAs fitted both specificity (> 98%) and sensitivity (> 90%) criteria according to French recommendations. Serology may offer valuable information during COVID-19 pandemic, but inconsistent performances observed among the 30 commercial assays evaluated, which underlines the importance of independent evaluation before clinical implementation.
Asunto(s)
Anticuerpos Antivirales/sangre , Prueba Serológica para COVID-19/métodos , COVID-19/sangre , Inmunoensayo/métodos , SARS-CoV-2/inmunología , COVID-19/virología , Humanos , Inmunoensayo/economía , Inmunoglobulina M/sangre , Juego de Reactivos para Diagnóstico , SARS-CoV-2/genética , SARS-CoV-2/aislamiento & purificación , Sensibilidad y EspecificidadRESUMEN
It has been claimed that Nigella sativa seeds (NSS), also known as black cumin, have antidiabetic and lipid-lowering properties. Our pilot study investigated the effects of powdered NSS on insulin secretion and lipid profile in healthy male volunteers. We conducted a double-blind, randomized, placebo-controlled 4-week trial in 30 subjects, receiving NSS powder (1 g/day) or placebo orally (15 subjects/group). Insulin secretion as determined by the hyperglycaemic clamp technique, insulin sensitivity as well as cholesterol and triglycerides serum concentrations, were measured before and after treatment. NSS powder administration was clinically well tolerated. It did not modify fasting glycaemia and insulinaemia, and was ineffective on glucose-induced insulin secretion and insulin sensitivity. No significant changes on serum lipids were observed after treatment in any treatment groups, nor between the two treatment groups. However, in the treated group only, there was a significant correlation between total cholesterol change after treatment and its baseline level (r = -0.71, P = 0.006, n = 13), and between low-density lipoprotein (LDL) cholesterol change after treatment and its baseline level (r = -0.74, P = 0.004, n = 13). No such correlations were found for high-density lipoprotein (HDL) cholesterol, and for triglycerides. These results do not confirm any NSS effect on glucose regulation; however, they suggest that NSS powder may be of interest in lowering lipid concentrations in hyperlipidaemic subjects.