Partial splenectomy in homozygous beta thalassaemia.

Partial splenectomy was performed on 30 patients with homozygous beta thalassaemia to reduce blood requirements and to avoid the risk of overwhelming postsplenectomy infections; 24 patients had thalassaemia major and six thalassaemia intermedia. Five patients received a high transfusion regimen before and after surgery and 25 a lower one. Follow up after surgery ranged from one to four years. Partial splenectomy improved the long term haematological state in the six patients with thalassaemia intermedia. Recurrence of hypersplenism occurred in nine of the 24 patients with thalassaemia major, however, and complete splenectomy was required. Serum IgM concentrations were not significantly modified by surgery. The mean (SD) residual spleen after surgery was 4.45 (2.36) cm measured by scintigraphy. No severe infections occurred after surgery; however, most patients were routinely treated with phenoxymethylpenicillin and the protective effect of the remaining spleen could not be exactly determined. Because of the possibility of recurrence of hypersplenism, routine partial splenectomy when splenectomy is needed in thalassaemia major is not advised, except in children under 5 years whose risk of overwhelming postsplenectomy infection is greatest.

[Treatment of homozygote beta thalassemia in Algiers. A 5-year follow-up of 66 patients]. / Traitement des beta-thalassémies homozygotes à Alger. Suivi de 66 malades sur 5 ans.

During the years 1982-1987, 66 patients with homozygous beta-thalassaemia were treated at the blood transfusion centre of Algiers. The patients, aged from 1 to 23 years in 1982, came from 48 families, 30 of which were issued from consanguinous unions. The patients fell into three groups according to the early institution and quality of treatment (blood transfusions, antibiotic therapy, desferrioxamine given when available). The beneficial clinical effects observed (satisfactory growth and development, reduction of splenomegaly and hypersplenism, attenuation of craniofacial malformations, performance at school) seemed to be directly related to the mean haemoglobin level prior to transfusion and to the early institution of treatment. Four patients died of anaemia and haemochromatosis. The incidence of viral contamination was 27.5 per cent for the hepatitis B virus and nil for the human immunodeficiency virus.

DNA haplotype distribution in Algerian beta thalassaemia patients. An extended evaluation by family studies and representative molecular characterization.

An evaluation of beta thalassaemia mutations and the associated chromosomal haplotypes has been made among Algerian thalassaemic patients in this extended series. The major features of our findings are: (i) due to elevated proportion of consanguinity, the frequency of true homozygotes for a defect is high; (ii) Despite this high homozygosity within families, the number of molecular defects resulting in beta thalassaemia are very heterogeneous within this population. This is exemplified not only by the high heterogeneity of haplotypes and associated mutations, but also by the definition of several new haplotypes, among which two of them were found to be associated with novel mutations. Family studies have been performed in parallel to evaluate the degree of feasibility of antenatal diagnosis in this population.

[Homozygous beta-thalassemia in Algeria. Study of 50 cases]. / La beta-thalassémie homozygote en Algérie. Etude de cinquante cas.

The clinical and laboratory data recorded at first presentation in 50 homozygous beta-thalassaemic untransfused children seen at the National Transfusion Centre, Algiers, are reported. These children came from 38 families, including 25 with consanguinous parents. Pallor was observed in all cases but jaundice and asthenia were present in only 11 and 10 children respectively. Splenomegaly was frequent (45 cases), as were skeletal changes mainly in the skull and face (35 cases). Haemoglobin levels ranged from 2.4 to 9.6 g/dl and MCV from 71 to 89 fl. Among these 50 patients, 34 had beta + thalassaemia and 16 beta 0 thalassaemia. Levels of foetal haemoglobin (Hb F) were similar in both groups but clinical symptoms appeared earlier in beta 0 thalassaemia patients. Thirty-seven cases were diagnosed as thalassaemia major and 6 as thalassaemia intermedia. Comparison of various parameters between siblings (20 children belonging to 9 families) showed no differences between Hb F and Hb A2 levels and clinical courses. These findings should be taken into consideration for the prenatal diagnosis of beta-thalassaemia.

Four new haplotypes observed in Algerian beta-thalassemia patients.

beta-Thalassemia, a heterogeneous group of human anemias affecting the expression of beta-globin, is caused by a number of molecular defects. Restriction endonuclease mapping of ethnic populations has revealed many polymorphisms within and around the beta-like globin genes, combinations of which are assigned as haplotypes. Several haplotypes appear to be strongly linked with the molecular defects causing thalassemia in Greek and Italian patients (Orkin et al. 1982). We describe here haplotypes from 40 Algerian beta-thalassemic patients and eight normals determined by restriction endonuclease mapping at seven polymorphic sites. Four haplotypes previously unreported were observed in these thalassemic patients; this argues the existence in this population of undescribed beta-thalassemia alleles. The knowledge of the haplotypes in thalassemic families could be used for prenatal diagnosis of homozygote forms.