Viscerocutaneous form of loxoscelism and erythrocyte glucose-6-phosphate deficiency

Em um período de cinco anos, todos os pacientes que exibiram a forma viscerocutânea do loxoscelismo foram investigados para a deficiência de glicose-6 fosfato desidrogenase eritrocitária, e em dois pacientes em um total de sete, esta deficiência foi encontrada. Este achado sugere que esta deficiência enzimática genética poderia ser uma das causas da hemólise que ocorre em decorrência da picada por Loxosceles.In a period of time of five years, all patients who exhibited viscerocutaneous form of loxoscelism were investigated for erythrocyte glucose-6-phosphate deficiency, and in two patients out of seven it was found this deficiency. This finding suggests that this genetical enzyme deficiency could account for the hemolysis after Loxosceles bite, at least in some of the cases

A novel point mutation in a class IV glucose-6-phosphate dehydrogenase variant (G6PD São Paulo) and polymorphic G6PD variants in São Paulo State, Brazil

In this study, we used red cell glucose-6-phosphate dehydrogenase (G6PD) activity to screen for G6PD-deficient individuals in 373 unrelated asymptomatic adult men who were working with insecticides (organophosphorus and carbamate) in dengue prevention programs in 27 cities in São Paulo State, Brazil. Twenty-one unrelated male children suspected of having erythroenzymopathy who were attended at hospitals in São Paulo city were also studied. Fifteen of the 373 adults and 12 of the 21 children were G6PD deficient. G6PD gene mutations were investigated in these G6PD-deficient individuals by using PCR-RFLP, PCR-SSCP analysis and DNA sequencing. Twelve G6PD A-202A/376G and two G6PD Seattle844C, as well as a new variant identified as G6PD São Paulo, were detected among adults, and 11 G6PD A-202A/376G and one G6PD Seattle844C were found among children. The novel mutation c.660C > G caused the replacement of isoleucine by methionine (I220M) in a region near the dimer interface of the molecule. The conservative nature of this mutation (substitution of a nonpolar aliphatic amino acid for another one) could explain why there was no corresponding change in the loss of G6PD activity (64.5% of normal activity in both cases)

Search of intravascular hemolysis in patients with the cutaneous form of loxoscelism Pesquisa de hemólise intravascular na forma cutânea de loxoscelismo

Haptoglobin assay, a highly sensitive method to detect intravascular hemolysis was carried out in the sera of 19 patients referred to Hospital Vital Brazil with the cutaneous form of loxoscelism in order to investigate the occurrence of mild intravascular hemolysis. Data from this series did not show decreased levels haptoglobin, ruling out intravascular hemolysis in these patients with cutaneous form of loxoscelism.<br>Dezenove pacientes que apresentaram a forma clínica cutânea do loxoscelismo foram investigados com o propósito de pesquisar hemólise intravascular sub-clínica, lançando mão da dosagem de haptoglobina, um método altamente sensível que permite detectar discreta presença de hemólise intravascular. Não foi encontrada diminuição de haptoglobina, o que descarta uma ação hemolítica do veneno da Loxosceles nestes pacientes