A curious case in clinical chemistry

A 77-year-old man had been suffering from breathlessness and fatigue was noted to be cyanosed. Further investigations revealed significant methaemoglobinaemia as high 16.3% (RI < 1.5 %) long-standing, mild thrombocytopenia thought secondary ITP. He multiple chronic medical conditions but none of the treatment thereof has described associated with methaemoglobinaemia. a lifelong non-smoker lives on acreage without exposure pesticides. Over years healthcare professionals commented dark colour his blood. Measurement enzymatic activity red cell methaemoglobin reductase showed significantly decreased 4.3 IU/gHb 12.9–18.9 IU/gHb). The patient commenced Vitamin C 1000 mg twice daily, which resulted in levels reducing 4.7 % improvement symptoms. During this presentation, causes, options will discussed.