Decreased phagolysosomal fusion of peripheral blood monocytes from patients with thalassemia major.

We evaluated the phagolysosomal fusion of peripheral blood monocytes from 15 patients with thalassemia major and 10 thalassemia major carriers using a cytomorphological method with acridine orange as fusion marker. The monocyte phagolysosomal fusion of thalassemic patients was decreased (49.6 +/- 8.6%, mean +/- SD) and differed significantly (p < 0.05) from those of carriers and normal controls (65.7 +/- 11.4% and 74.6 +/- 5.7%, respectively). In vitro deferoxamine partially improved monocyte phagolysosomal fusion of patients with thalassemia major, and did not affect monocyte function in carriers and healthy subjects. Furthermore, in vitro addition of ferrous sulfate decreased normal phagolysosomal fusion. We conclude that the monocyte phagolysosomal fusion dysfunction of thalassemic patients could be related to iron overload.

[Neutrophil chemotactic dysfunction in multitransfused thalassemia patients]. / Disfunción quimiotáctica de los neutrófilos en pacientes talasémicos politransfundidos.

PURPOSE: To evaluate the chemotactic capability of neutrophils in thalassaemic patients under poly-transfusion regimens and in thalassaemia carriers. PATIENTS AND METHODS: Twenty-one patients in multi-transfusion regimen diagnosed in the Ricardo Gutiérrez Children Hospital were studied. Of them, 17 had thalassaemia major, 3 S/beta thalassaemia and one sickle-cell anaemia. Twenty-one normal subjects comprised a control group. Chemotaxis was evaluated by two methods, namely, migration under agarose layer and in microchemotaxis chamber under stimulation with N-formyl-methionyl-n-phenylalanine at optimal concentrations of 10(-5) M and 10(-6) M, respectively. RESULTS: In thalassaemia major patients, directed mobility of neutrophil assessed by both methods was significantly decreased with regard to the normal controls, whereas random mobility was preserved. The four patients under poly-transfusion who had not thalassaemia major showed the same neutrophil defect. On the contrary, chemotaxis and random mobility of the neutrophils from thalassaemia carriers (thalassaemia minor) were similar to those of the normal controls. CONCLUSIONS: These results suggest that the defect found in the patients might be caused by transfusion overload.