Seroprevalence of Anti-SARS-CoV-2 Antibodies in Blood Donors from Nuevo Leon State, Mexico, during 2020: A Retrospective Cross-Sectional Evaluation.

The progression and distribution of the SARS-CoV-2 pandemic are continuously changing over time and can be traced by blood donors' serological survey. Here, we investigated the seroprevalence of anti-SARS-CoV-2 antibodies in blood donors in Nuevo Leon, Mexico during 2020 as a strategy for the rapid evaluation of the spread of SARS-CoV-2 and asymptomatic case detection. We collected residual plasma samples from blood donors who attended two regional donation centers from January to December of 2020 to identify changes in anti-SARS-CoV-2 IgG prevalence. Plasma samples were analyzed on the Abbott Architect instrument using the commercial Abbott SARS-CoV-2 IgG chemiluminescent assay. We found a total of 99 reactive samples from 2068 analyzed plasma samples, resulting in a raw prevalence of 4.87%. Donors aged 18-49 years were more likely to be seropositive compared to those aged >50 years (p < 0.001). Weekly seroprevalence increased from 1.8% during the early pandemic stage to 27.59% by the end of the year. Prevalence was 1.46-fold higher in females compared to males. Case geographical mapping showed that Monterrey city recorded the majority of SARS-CoV-2 cases. These results show that there is a growing trend of seroprevalence over time associated with asymptomatic infection that is unnoticed under the current epidemiological surveillance protocols.

Donor platelet and leukocyte count as predictive factors of the quality of platelet concentrates obtained from whole blood by semiautomated fractionation.

Platelet concentrates (PCs) obtained from whole blood are produced by fractionation of the buffy coat (BC) or the platelet-rich plasma. Despite the improvements in the technologies used for the hemocomponent fractionation, the proportion of PCs that do not accomplish the quality requirements is high. This study aimed to determine whether the basal platelet and leukocyte counts are predictive factors of the quality of the PCs obtained from BC by semiautomated fractionation. Quality control registers of 196 PCs were analyzed. Gender- and age-dependence of the blood cell count and the characteristics of PCs were evaluated. Platelet yield and residual leukocytes in the PCs were correlated with the platelet and leukocyte counts and the age of the donors. Predictive efficacy was assessed, and an optimal cut-off was established. The proportions of PCs accepted and rejected by using or not the optimal cut-off were compared. 50.0% of the PCs accomplished all the quality control requirements. Female donors had a higher basal platelet count than males. A correlation was observed between basal platelets and platelet yield, but not between basal leukocytes and residual leukocytes. The basal platelet count predicted the quality of the PCs. A cut-off of 231,000 platelets/mm3 was established, but it did not improve the proportion of accepted PCs. In conclusion, we found that the basal platelet count is correlated with the platelet yield. The basal leukocyte count is not correlated with the residual leukocytes. The established cut-off for the basal platelet count did not improve the proportion of accepted PCs.

Clinical presentation in thrombotic thrombocytopenic purpura: Real-world data from two Mexican institutions.

BACKGROUND: Thrombotic thrombocytopenic purpura (TTP) is a hematologic disease that can be fatal if not treated early. We aimed to describe the clinical characteristics of Mexican patients with idiopathic TTP. STUDY DESIGN AND METHODS: We conducted a retrospective study, including all adult patients diagnosed with idiopathic TTP from 2011 to 2017 in two Mexican centers. We further compared our results with the published literature. RESULTS: Twenty patients were included; 70% were female, with a median age of 38.5 years at diagnosis (range 16-63). The median time from onset of symptoms to hospital admission was 1.5 days (range 0-16). Most patients (85%) presented with at least one systemic manifestation at admission (including fever) and 90% had neurological symptoms, most of them major (70%) including loss of consciousness, transient focal abnormalities, headache, and confusion. Only one patient (5%) had the classical pentad at the time of admission. Kidney failure was present in 25% of patients and hemorrhagic symptoms in 60%. Digestive and cardiorespiratory symptoms were less common (45% and 15%, respectively). Median platelet count and lactate dehydrogenase were 10 500/µL and 1319 IU/L, respectively. Eighty percent of patients achieved remission following treatment. Patients admitted within the first 48 hours (after the onset of symptoms) tended to have better overall survival. CONCLUSION: Clinical presentation in Mexican TTP patients is similar to that in other countries. Early admission and a high suspicion for the disease will avoid delays in the initial work-up and initiation of therapy, further improving prognosis.