Favism: Disordered Erythrocyte Calcium Homeostasis

• Published in: Blood 1985-08, Vol.66 (2), p.294-297
• Main Authors: De Flora, A., Benatti, U., Guida, L., Forteleoni, G., Meloni, T.
• Format: Article
• Language: English
• Subjects: Acute Disease; Anemias. Hemoglobinopathies; Biological and medical sciences; Calcium - metabolism; Calcium-Transporting ATPases - metabolism; Cell Separation; Diseases of red blood cells; Erythrocyte Count; Erythrocytes - drug effects; Erythrocytes - enzymology; Favism - enzymology; Hematologic and hematopoietic diseases; Homeostasis; Humans; In Vitro Techniques; Ion Channels - metabolism; Male; Medical sciences; Methemoglobin - analysis; Potassium - metabolism; Pyrimidinones - pharmacology
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V66.2.294.294

The biochemical events that take place during acute hemolysis of G6PD-deficient subjects in favism are far from being elucidated. Evidence is here reported for a constantly and heavily disordered calcium homeostasis in the erythrocytes from seven favic patients. The abnormality, ie, a significantly impaired calcium ATPase activity and a parallel marked increase of intracellular calcium levels, was characteristic of the acute hemolytic crisis although unrelated to the attendant reticulocytosis. Concomitantly, a remarkable decrease of intracellular potassium was also observed. The mean ± SD Ca2+-ATPase activity in the favic patients was 20.8 ± 7.8 μmol P***i/g Hb/h compared with 37.2 ± 8.5 in the matched controls represented by 12 healthy G6PD-deficient subjects (P < .001). The mean ± SD intraerythrocytic calcium content was 288 ± 158 μmol/L of erythrocytes in the favic patients as compared with 22.0 ± 8.2 in the G6PD-deficient controls (P < .001). The intraerythrocytic potassium content was 76.6 ± 19.3 mmol/L of erythrocytes in the favic patients and 106.6 ± 8.2 in the G6PD-deficient controls (P < .001). In vitro incubation of normal and G6PD-deficient erythrocytes with divicine, a pyrimidine aglycone present in fava beans and strongly implicated in the pathogenesis of favism, reproduces most of these events, including drop of calcium ATPase, increased intracellular calcium, and leakage of erythrocyte potassium.