The child has indirect hyperbilirubinemia and anemia with increased reticulocyte count suggestive of acute hemolysis. The cardiac failure may be related to the acute anemia. There is no external blood loss. Thus the destruction of RBCs may be in the spleen due to infected RBCs or due to drug related hemolysis. The hemolysis may be due to infection such as malaria. Since the child has responded to
Chloroquine with no further fever episode, malaria induced destruction seems unlikely. Also Coombs test is negative ruling out autoimmune anemia. Since the child was given
Primaquine and also is a male child G-6-PD deficiency is a possibility. He was screened for G-6-PD deficiency, which was low. The parents were negative for G-6-PD deficiency.
G-6-PD (Glucose-6-phosphate dehydrogenase) is an enzyme present in the RBC. Deficiency of this enzyme leads to shortening of the red-cell life span and hereditary non-spherocytic hemolytic anemia. It is inherited as an X-linked disorder. The life span (particularly of older RBCs) is shortened particularly during drug administration and infection. Drug induced hemolysis in G-6-PD deficient cells is accompanied by formation of Heinz bodies due to inability to reduce NADP+ to NADPH at a normal rate. Hence hemoglobin is denatured and destroyed by the spleen. The major clinical feature is hemolytic anemia in males usually the anemia is episodic. Drugs to be avoided in G-6-PD deficiency are – Furazolidone, Nalidixic acid, Nitrofurantoin, Phenylhydrazine, Primaquine, sulfacetamide, sulfamethoxazole, sulfapyridine and chloramphenicol. Chemicals to be avoided are Methylene blue, Naphthalene, TNT.