Objectiveto verify whether the review criteria for automated blood counts suggested by the International Consensus Group for Hematology Review of the International Society for Laboratory Hematology are suitable for the Hematology Laboratory of Hospital de Clinicas, Universidade Federal do Paraná.Methodsinitially, the review criteria of the International Society for Laboratory Hematology were adapted due to limitations in the Institution's electronic hospital records and interfacing systems. The adapted review criteria were tested using 1977 samples. After this first assessment, an additional 180 inpatient samples were analyzed to evaluate the screening criteria of the review criteria in conjunction with positive smear findings established by the institution. The performance of the review criteria was verified by determining false positive, false negative, true positive and true negative rates, sensitivity, specificity, positive predictive value, negative predictive value, microscopic review rate and efficiency.Resultsinitial analysis showed false negatives = 6.73%, false positives = 23.27%, microscopic review rate = 46.03% and efficiency = 70.0%. An evaluation of the screening criteria adapted from the review criteria together with the positive smear findings of the institution showed false negatives = 15.5%, false positives = 10.5%, microscopic review rate = 37.3% and efficiency = 73.8%. In both situations the safety limit (false negative <5%) recommended by the review criteria was exceeded.Conclusionsthe review criteria adapted from the International Society for Laboratory Hematology are neither suitable nor safe for use in the hematology laboratory of the Hospital de Clinicas. This implies a need to develop and validate institution-specific review criteria in order to decrease false negative results to an acceptable and safe rate for patients.

The mature human erythrocyte, when submitted to oxidative stress, can demonstrate depletion of reduced glutathione, oxidation of the hemoglobin molecule and aggregation of complexes of iron close to the membrane. These can produce abnormalities in the erythrocyte membrane and hemolysis. The aim of this work was to study the antioxidative action of vitamin C (vit. C), deferroxamine (DFO) and the flavonoids quercetin and rutin in normal human erythrocytes, submitted to in vitro oxidative stress induced by tert-butylhydroperoxide ((t)BHP). Venous blood was collected in citrate-phosphate-dextrose (CPD) solution, as anticoagulant, from healthy adult individuals after informed consent. The erythrocytes were resuspended in PBS to obtain 35% globular volume, and then submitted to the oxidative action of (t)BHP for up to 30 min, with or without previous incubation for 60 min with vit. C, DFO, quercetin and rutin. Decrease in the GSH concentration, G6-PD and GR activities, and increase in the methemoglobin and Heinz bodies (HB) formation, occurred with the increase in (t)BHP concentration. (t)BHP did not effect on the membrane proteins detected by SDS-PAGE. Quercetin, partially prevented the GSH decrease and the formation of HB, but did not prevent MetHb formation from oxidative damage by (t)BHP. Rutin, after (t)BHP induction, prevented the GSH decrease and the formation of HB. Vit. C, had no influence on the depletion of GSH, inhibited partially the metHb formation, and it protected GR, but not G6-PD from oxidative damage by (t)BHP. DFO partially inhibited the metHb formation and GSH decrease, but it did not protect GR and G6-PD from oxidative damage by (t)BHP. The results obtained suggest that vit. C, DFO and the flavonoids quercetin and rutin contribute to the decrease in the oxidative stress caused by (t)BHP.

The oxidative action of 1 mmol l(-1) phenylhydrazine hydrochloride (PH) was studied on human erythrocytes treated with the antioxidants vitamin C (vit. C) and vitamin E (vit. E). The erythrocytes were resuspended in PBS to obtain 35% cell packed volume, and then submitted to the oxidative action of PH for 20 min, with or without previous incubation for 60 min with vit. C or vit. E. Heinz bodies and methemoglobin formation by PH were inhibited in the presence of vit. C. At the concentration of 90 mmol l(-1), vit. C, not only seemed to lose its antioxidant effect, but it also promoted an increase in methemoglobin formation. Vit. C (0.5-80 mmol l(-1)) did not protect against GSH depletion by PH. Vit. C alone produced insignificant hemolysis, but, in the presence of PH, the hemolysis indices were more accentuated. Heinz body formation by PH was inhibited in the presence of vit. E. Formation of methemoglobin induced by PH was decreased by vit. E (0.1-2 mmol l(-1)), although vit. E (3-80 mmol l(-1)) did not lower the concentration of methemoglobin and did not lead to the recovery of the GSH depleted by PH. The results obtained suggest that vit. C and vit. E contribute to the decrease in oxidative stress caused by PH.