|Year : 1982 | Volume
| Issue : 1 | Page : 4-8
Symptomatic beta thalassemia trait (A study of 143 cases).
MB Agarwal, BC Mehta
M B Agarwal
|How to cite this article:|
Agarwal M B, Mehta B C. Symptomatic beta thalassemia trait (A study of 143 cases). J Postgrad Med 1982;28:4-8
|How to cite this URL:|
Agarwal M B, Mehta B C. Symptomatic beta thalassemia trait (A study of 143 cases). J Postgrad Med [serial online] 1982 [cited 2020 Sep 26 ];28:4-8
Available from: http://www.jpgmonline.com/text.asp?1982/28/1/4/5608
Carriers of beta-thalassemia trait (BIT) can have varying degree of anemia. Some of them have no symptoms and therefore can be detected only in a population survey or as a part of family study if other members are symptomatic or have thalassemia major. Others have symptoms for which medical help is sought. Anemia is not amenable to treatment. Therefore some of these persons are likely to present as cases of refractory anemia. There are several haematological abnormalities in cases of BTT, e.g. raised Hb-A2, raised Hb-F, decreased osmotic fragility and abnormal red cell morphology. However each one of these may be normal in a significant proportion of BTT cases. Here we report the clinical and haematological data of 143 symptomatic cases of BIT diagnosed on the basis of raised Hb-A2. Raised Hb-A2 has been accepted as a reliable criterion for the diagnosis of BTT.
MATERIAL AND METHODS
Patients with anemia (Hb < 14.0 g% in males and < 12.0 g% in females) with no evidence of "nutritional deficiency", renal or hepatic derangement (normal urinary findings, blood urea, SGPT and serum protein electrophoresis) or chronic infection were taken up for study. Hemoglobin (cyanmethemoglobin method). Hb-F (Singer's method), Hb-A2 (paper electrophoresis), red cell morphology and osmotic red cell fragility were determined in all cases. Patients were labelled as beta-thalassemia trait only if they had Hb-A2 > 3.5%. Hb-F of > 2.0%, Hb-A2 of 3.5% and hemolysis of < 55% at 0.4% buffered saline were considered abnormal. Presence of hypochromia, anisopoikilocytosis, target cells, basophilic stippling and normoblasts in the peripheral smear, either singly or in any combination was considered abnormal.
Cases of BTT usually have a mild disorder. The severity was said to be intermediate if they needed more than occasional blood transfusion (5 cases), they had splenomegaly beyond 10 cm (4 cases), non-healing ankle ulcers (3 cases) or haemochromatosis and its complications (2 cases). Other causes for severity of anemia, splenomegaly and ankle ulcers were carefully excluded.
Over the last 11 years, using the criteria described above, 143 cases were detected to have beta-thalassemia trait. Their community distribution [Table 1], frequency of symptoms and signs [Table 2] and [Table 3] and results of hematological investigations [Table 4] were studied. Frequency of abnormal diagnostic criteria is shown in [Table 5] while this data is compared with the data obtained from the asymptomatic beta-thalassemia trait (i.e. parents of patients suffering from proved Cooley's anemia) in [Table 6.]
Over the last 11 years, 143 cases presenting for one or other symptoms were found to have beta thalassemia trait while during the same period, 171 asymptomatic persons were detected to have beta thalassemia trait during family studies of children with Cooley's anemia. Majority of the cases belonged to Sindhi, Lohana, Maratha or backward communities.
Mean Hb level was significantly lower in symptomatic beta thalassemia group (9.66 ± 2.19 g%) than in asymptomatic group (11.3 ± 1.8 g%)4 (p < 0.05). Even in the symptomatic group, the hemoglobin level was lower in patients with palpable splenomegaly (8.92 ± 2.23 g%) compared to those who did not have palpable spleen (9.9 ± 2.13 g%.) (p = 0.05). Fifty eight patients had received hematinics for long periods without significant benefit.
* Hb level and percentage of Hb-A2, were not compared as the first was the cause of referral in all the symptomatic cases and the second was considered as the only definite criteria for the diagnosis of BTT in symptomatic group.
Besides symptoms due to anemia, jaundice, pain in abdomen and hepatosplenomegaly seem to be common manifestations in symptomatic beta thalassemia trait, being present in 20-25% of cases. Abdominal pain and swelling were other common complaints. Clinical manifestations severe enough to label patients as thalassemia intermedia were present in 14 (9.9%) cases. Similar number of other patients had either more than one episode of jaundice or an episode of jaundice persisting for over 4 months. Leg ulcers were encountered in only 3 cases.
There does not seem to be significant difference in various diagnostic criteria in symptomatic and asymptomatic cases of BIT [Table 6].
Clinical varieties of heterozygous thalassemia are said to segregate in families. However, all the 14 patients who had clinical picture of thalassemia intermedia had 1-3 relatives (parents, siblings) who had asymptomatic beta thalassemia trait. There is no satisfactory explanation for clinical variations in the families. Possibility of environmental factors and/or interactions with other genetic factors (nonthalassemia) cannot be ruled out. Variable penetrance of gene has also been postulated to explain such and other differences.
We thank Dr. C. K. Deshpande, Dean, K.E.M. Hospital for permission to publish the paper. The work was supported by grants from Seth G.S. Medical College and K.E.M. Hospital Research Society.
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