Usefulness of cryohemolysis test in the diagnosis of hereditary spherocytosis

The clinical suspicion of hereditary spherocytosis (HS) must be confirmed at the clinical laboratory. The osotic fragility test (OFT) and the autohemolysis test (AHT) are the worlwide accepted assays to establish a definitive diagnosis of HS; however, they have some disadvantages. We describe herein our experience with the cryohemolysis test (CHT) as a tool to confirm the HS diagnosis. We included four groups of subjects, namely, patients with clinical HS, patients with mechanical heart valve prosthesis, malignant hematological diseases and healthy blood donors. CHT was carried out in all the groups, while OFT and AHT only in the HS patients and healthy individuals. OFT and AHT were performed according to previously described techniques. CHT was performed using red blood cells incubated in a hypertonic solution, preheated for 10 min and then tranferred to an ice bath for an additional 10 min. The resulting cryohemolysis was determined mesuring the free hemoglobin in the sample. There were no differences among the groups in terms of general characteristics. All HS suspicious patients had a positive OFT and AHT. CHT was positive in all patients from the HS group but in none of the subjects from the control groups (p<0.001). We found that CHT is a faster and easier-to-perform assay compared with OFT and AHT. Moreover, using CHT, the zone between normal and abnormal results is wider than OFT or AHT. We propose 0.7 to 11 percent hemolysis as reference values for CHT

Diagnostic value of the copper/zinc ratio in digestive cancer: A case control study

The aim of this study was to assess the accuracy of the copper/zinc ratio (Cu/Zn ratio) in the evaluation of a large group of patients with digestive cancer compared to gender and age-matched control subjects. A total of 282 patients was studied and separated into three groups: group I (n=75), patients with digestive cancer, group II (n=112), patients with bening digestive disease, and group II (n=95), healthy subject. Serum levels of copper and zinc were measured by atomic absorption spectrophotometry. The results showed that the serum levels of copper (mg/dL) in patients with digestive cancer (91.6 ñ27.3, p<0.05) were significantly higher than in patients with benign digestive diseasde (75.8 ñ 19.8) or healthy subjects (54.4 ñ 8.9) and the serum levels of zinc (mg/dl) were significantly lower (68.7 ñ 21.9, p<0.05) compared to benign digestive disease patients (80.1 ñ 18.7) or healthy subjects (100 ñ 11.4 mg/dl). The Cu/Zn ratio was also significantly higher in patients with digestive cancer (1.45 ñ .58, p<0.05) than those with benign digestive disease (0.95 ñ 0.28) or healthy subjects (0.55 ñ 0.13). Considering a cutoff value of 0.87, the sensitivity of the copper/zinc ratio was 82.2 percent, with a specificity of 65.7 percent, a positive predictive value of 45.8 percent and a negative predictive value of 91.3 percent. In conclusion, Cu/Zn ratio was found to be considerably higher in patients with digestive cancer compared to age-and gender-matched controls, with a sensitivity of 82.2 percent that might be useful in the evaluation of suspected malignancy