Long-term hydroxyurea therapy in beta-thalassaemia patients.

OBJECTIVE: The study aimed to investigate the use of hydroxyurea (HU) for the treatment of beta-thalassaemia (beta-thal) patients. METHODS: We examined the haematological effects of orally administered HU (10-20 mg/kg/d) in 11 patients, including four beta-thal major and seven beta-thal intermedia patients. Complete blood count and levels of foetal haemoglobin (HbF), liver enzymes and serum creatinine were evaluated before and during HU. Response to therapy was evaluated at 6 months of treatment. RESULTS: A substantial increase in haemoglobin (Hb) level (4.1 g/dL), leading to complete withdrawal from a regular transfusion programme, was observed in one unique beta-thal major patient. In the beta-thal intermedia patients, increases in Hb level of 1.3, 1.9 and 2.0 g/dL were observed in three of seven (42.9%) patients during HU therapy. The mean values of Hb, mean corpuscular haemoglobin (MCH), and HbF were higher during HU treatment than baseline values (8.7 vs. 7.7 g/dL, P = 0.05; 26.7 vs. 22.9 pg, P = 0.05; 57.2 vs. 44.9%, P = 0.04; respectively). In contrast, the mean reticulocyte count measured during therapy decreased (97.0 x 10(9) vs. 632.0 x 10(9)/L, P = 0.03). No correlations were observed between levels of Hb and HbF (r = 0.77, P = 0.10), and levels of Hb and reticulocyte counts (r = 0.26, P = 0.31). No significant toxicity was observed in our patients. CONCLUSION: These results suggest that HU may improve Hb levels in beta-thal. Thus, we may conclude that a large trial concerning the response to HU in these patients should be carried out to clarify this issue.

Studies on the components of the contact phase system in patients with acute nonlymphoblastic leukemia

The objective of the present study was to evaluate factors of the plasma kallikrein system in patients with acute nonlymphoblastic leukemia (ANLL), and compare the results to a normal control group. A prospective study was performed in the Tertiary Health Care Institution, Hemocentro, Campinas State University, Campinas, Sao Paulo, Brazil. Thirty-five patients, diagnosed as ANLL between 1988 and 1991, were considered for participation. Eleven patients were not elegible, according to the exclusion criteria: infection/septicemia, previous treatment of blood transfusion. The study was performed with 24 ANLL patients, average age 34 years (16-69 years), 14 men and 10 women. Nineteen healthy volunteers, workers from the Hematology Center, average age 32 years (21-59 years), 11 men and 8 women, were the control group. Plasmatic prekallikrein, C1-inhibitor, alpha 2-macroglobulin, activated partial thromboplastin time, prothrombin time, factor XII, factor XI, factor V and prealbumin were measured. Plasmatic prekallikrein (p=0.02) and prealbumin (p=0.03) were significantly decreased, and prothrombin time increased (p=0.003) in the patient group when compared to the control. Significant correlation (r=0.49, critical value=0.43, p<0.05) between prekallikrein and prealbumin, and between prothrombin time and factor V (r=0.54, critical value=0.44, p<0.05) was demonstrated in the patient group. No correlation was found between parameters analysed and circulant blast count or leukemia subgroups. Statistical analysis was performed by the Willcoxon test. Correlation between the parameters was also verified. These results suggest activation of the contact system or impaired liver synthesis in patients with ANLL, and could contribute to disease complications.