Utility and importance of accurate Hb A2 measurements for defining a strategy for ß-thalassemia screening: experience in the Balearic Islands, Spain.

The high heterogeneity in regional profiles of ß-thalassemia (ß-thal) mutations highlights the need for population-specific carrier detection strategies. Our aim was to analyze the relationship between hematological values and ß(0) and ß(+) mutations in 154 Balearic ß-thal heterozygotes, in order to establish the most optimized mutation carrier detection strategy to be used to manage the disease in our population. The Hb A2 level was the best parameter for discriminating between both types of carriers. Taking into account the cut-off point value of 4.85% (Hb A2), obtained by a receiver-operating characteristic (ROC) curve analysis, we proposed an algorithm that would use a real-time polymerase chain reaction (RT-PCR) hybridization probe assay technique to detect one of the two most common mutations in the Balearic population, namely codon 39 (C>T) and IVS-I-110 (G>A), depending on the Hb A2 value of the patient.

Effect of co-inheritance of ß-thalassemia and hemochromatosis mutations on iron overload.

Co-inheritance of mutations in the HFE gene underlying hereditary hemocromatosis (HH) may play a role in the variability of iron status in patients with ß-thalassemia (ß-thal) minor. Different studies have yielded conflicting results: some suggest iron overload might arise from the interaction of the ß-thal trait with homozygosity or even heterozygosity for HFE mutations and others that it was unrelated to the HFE genotype. Because of the high frequency of HFE mutations in the Balearic Islands, where the ß-thal trait is also moderately common, it is of interest to evaluate the effect of the co-inheritance of mutations in both genes on the severity of iron loading. A retrospective analysis of 142 individuals heterozygous for ß-thal was performed to investigate the effect of HFE mutations on iron status of these patients. No significant differences were detected between ß-thal carriers with and without HFE mutations. These results suggest that in the Balearic population the ß-thal trait does not tend to be aggravated by the co-inheritance of HFE mutations.

Different effects of exercise tests on the antioxidant enzyme activities in lymphocytes and neutrophils.

We have determined the effects of maximal and submaximal cycloergometer tests on the antioxidant enzyme defences of neutrophils and lymphocytes. We also compared the neutrophil and lymphocyte basal enzyme antioxidant activities. A total of 17 well-trained amateur athletes, runners, and cyclists participated in this study. Two tests were performed on an electromagnetic reduction cycloergometer: the maximal exercise test, and the submaximal prolonged exercise test. Blood samples were taken before and after the tests. Basal enzyme activity of superoxide dismutase was higher in lymphocytes but neutrophils presented higher activities of catalase and glutathione peroxidase. The maximal test increased the circulating number of lymphocytes and the activities of catalase and glutathione peroxidase. No changes were observed in lymphocyte number or in lymphocyte antioxidant enzyme activities after the submaximal test. The circulating number of neutrophils increased significantly after the submaximal test. Maximal and submaximal tests decreased the activities of neutrophil glutathione dependent antioxidant enzymes (glutathione peroxidase and glutathione reductase), but no changes were observed in catalase or superoxide dismutase activities after either test. Neither the maximal nor submaximal test produced increases in serum activities of lactate dehydrogenase and creatine kinase (CK).