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|Year : 1984 | Volume
| Issue : 3 | Page : 196-7
Benign sickle cell anaemia (a case report).
Teckchandani SD, Pandya PM, Chandes FP
|How to cite this article:|
Teckchandani S D, Pandya P M, Chandes F P. Benign sickle cell anaemia (a case report). J Postgrad Med 1984;30:196
The diagnosis of sickle cell anaemia (SCA) is usually made in childhood, often before the age of 2 years. In early childhood, the mortality is high, many children dying in the first 7 years of life. However, only recently it has been appreciated that a significant number of adults with SCA are able to lead a relatively normal life, punctuated by only occasional episodes of illness. Here we wish to present such a case in an adolescent with mild clinical symptoms.
A 15 year old female, asymptomatic at present, came to us with a past history of mild recurring jaundice for the last 6 months. On clinical examination, there was questionable icterus. Her haemoglobin was 10 gm%, PCV 31% and ESR 23 mm at the end of one hour (Westergren). Total WBC count was 15,000 per cmm with P-70%, L-24%, E-1%, M-5% with 2 normoblasts per 100 WBCs. RBCs showed mild hypochromia, anisocytosis and poikilocytosis with many target cells and a few sickle-shaped cells. Her serum total bilirubin was 2 mg% with direct bilirubin of 1.2 mg%; the reticulocyte count was 9%. Sickling test was strongly positive. Her hemoglobin electrophoresis was carried out at pH = 8.9 on filter paper which showed a broad band in the region of HbS. The quantitative analysis revealed HbS to be 74.16%, HbF, 23.64% and HbA2, 2.59%.
The acid elution test showed an uneven distribution of HbF between the red cells. Electrophoretic study of all the family members (parents and brothers) showed the presence of sickle trait with HbF varying from 43.12 to 49.29%.
This family belongs to a scheduled caste community (Mahar) which is known to have a high incidence of sickle cell disease.
A number of factors influence the rate and degree of HbS aggregation required to produce sickling of red cells. Hb-C, Hb-D and Hb-O greatly potentiate sickling by interacting with Hb-S and promoting gel formation. Hb-F interacts poorly or not at all with Hb-S. Hb-F is postulated to act as inert diluent of Hb-S solutions. Singtr and Singer noted that Hb-F interfered with Hb-S aggregation in proportion to its relative concentration. Bertles and Milner have also been able to demonstrate that cells with a high Hb-F concentration survive longer in circulation and do not readily form irreversibly sickled cells (ISCs). High levels of Hb-F are always associated with low ISC counts and hence this relationship is reflected in the significant inverse correlationship between Hb-F and ISCs in patients with sickle cell disease.
The most striking evidence for the ameliorating effect of high levels of Hb-F was apparent in the Saudi Arabian population with sickle cell disease. This group of patients manifested with mean Hb-F levels of approximately 20% and were characterised by an extremely benign clinical course, high Hb levels, less rapid haemolysis and a virtual absence of painful crises. This finding suggests that this group has a genetically determined ability to synthesize large amounts of Hb-F, possible reasons being that the population may be carrying an extra gamma loci; alternatively, many of these patients, in addition to being homozycous for Hb-S, carry one or more B-thalassemia gene.
High Hb-F levels in sickle cell disease are associated with more normal red cell survival, more normal O2 affinity and more normal red cell characteristics whereas clinically they have more benign course.
We are thankful to Dr. C. K. Deshpande, Dean, Seth G.S. Medical College and K.E.M. Hospital, Parel, Bombay 400-012 for his kind permission to publish this paper.
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