No abstract

SUMMARY The effectiveness of the one tube method of osmotic fragility with three buffered solutions (0-32 %°saline, 0 36 % saline, and tyrode) as a screening test for f-thalassaemia trait was evaluated in several groups of subjects from Greece, Yugoslavia, and Thailand. The results clearly demonstrated that 0 36 % saline is the most sensitive and effective solution since it could detect 96 to 100% of heterozygotes with r-thalassaemia, compared to about 80%. with both 0-32% saline and tyrode.However, 0 36 % saline gave false positive results in normal subjects and was also positive in haematological disorders which influence osmotic fragility. The screening test with 0-36% saline was applied more precisely in 1371 subjects. The test was false positive in 41 (9-1 %) of 455 normal subjects while of 438 confirmed heterozygotes with 3-thalassaemia it was positive in 431 (98 %) and negative in only seven (2 %). The test was also found to be positive in 80 % of patients with iron deficiency anaemia and ao-thalassaemia trait, in 68 % of patients with Hb E trait, in 40 % of patients with Hb S trait, and in 78 % of heterozygotes with rare haemoglobin variants.The increased sensitivity and effectiveness of 0.36% saline in detecting p-thalassaemia trait and other disorders influencing osmotic fragility as compared to 0-32 % saline and tyrode solutions was also confirmed in a study of 384 unselected schoolchildren.The ,-thalassaemias have been described all over the world,1 2 but in certain countries the high prevalence of the abnormal gene causes serious problems in public health. In general, heterozygotes for the r-thalassaemias are characterised by hypochromic microcytic anaemia, decreased red cell osmotic fragility, and raised Hb A2 or Hb F or both. In addition, there are some rare variants which can be detected only by chain synthesis.3-5

No abstract

No abstract