"Bad things come in small packages": predicting venom-induced coagulopathy in Bothrops atrox bites using snake ontogenetic parameters.

Introduction: Snake venom composition shows significant inter- and intra-species variation. In the case of the viperid species Bothrops atrox, responsible for the majority of snakebites in the Amazon region, geographical and ontogenetic variables affect venom composition, with ecological and medical implications. Previous studies had shown that venom from neonate and juvenile Bothrops specimens have a higher in vitro coagulant activity. The aim of this investigation was to assess the association of clinical outcomes, such as venom-induced coagulopathy and local complications, with B. atrox ontogenetic variables.Methods: This study explored the relationship between some clinical parameters in patients suffering envenomations by B. atrox in the Amazon and several morphometric parameters of the snake specimens causing the bites.Results: There were 248 specimens confirmed as agents of envenomation, mostly female snakes (70.5%) and classified as juveniles (62.7%). Patients bitten by neonates compared to adult snakes [OR = 2.70 (95%CI 1.15-6.37); p = .021] and by snakes with white tail tip [OR = 1.98 (95%CI 1.15-3.41); p = .013] were more likely to develop coagulopathy. Time from patient admission to the unclottable blood reversion was not affected by the snake gender (p = .214) or age (p = .254). Patients bitten by neonate (p = .024) or juvenile snakes (p < .0001) presented a lower frequency of moderate to severe edema, as compared to those bitten by adult snakes. In agreement with experimental observations, patients bitten by neonates and by snakes with a white tail tip were more likely to develop coagulopathy than those bitten by adult snakes. In contrast, envenomations by adult snakes were associated with a higher incidence of severe local edema.Conclusion: Despite these variations, no difference was observed in the time needed to recover blood clotting in these patients after Bothrops antivenom administration.

Frequency of CCR5Δ32 mutation in blood donor candidates from the Fundação Hospitalar de Hematologia e Hemoterapia do Amazonas, Brazil

The chemokine receptor CCR5 is a major co-receptor for HIV-1 entry into the host cell. Deletion of 32 bp (Δ32) alters the receptor structure and is associated with the protection against infection. The distribution of allelic variant depends on several factors influencing the epidemiology of HIV infections. Thus, the present study sought to estimate the allelic frequency of the CCR5 gene variant / CCR5Δ32 in blood donor candidates with and without positive serology for HIV-1+ at the HEMOAM Foundation. 239 candidates were enrolled and divided into two groups, HIV-1+ (101 individuals) and HIV- controls (138 individuals). After collecting peripheral blood, DNA was extracted and allele-specific PCR for identification of CCR5Δ32 polymorphism, was performed. The results obtained were analyzed using Stata (v.13). The groups were of similar ages, predominantly male and the distribution of genotypes and alleles were in Hardy-Weinberg equilibrium (p=0.725 and p=0.879, respectively). The highest frequency was wild genotype, followed by the heterozygous genotype in both groups (control and the HIV-1+ ). When the frequencies in HIV-1+ subgroups were analyzed, the absence of the allelic variant CCR5Δ32 subgroup ELISA(+) Westen Blot(+) was noted. Therefore, our data indicate that CCR5Δ32 polymorphism has a low frequency in the population studied.