Deep vein thrombosis associated with marked hyperhomocysteinemia and active pulmonary tuberculosis

We report a 32-year-old male patient presented with acute deep vein thrombosis of his right leg after recent onset of active pulmonary tuberculosis. Marked hyperhomocysteinemia (> 50 μmol/L), folic acid deficiency, and abnormal coagulation profiles (elevations of fibrinogen and fibrinogen degradation product) were noted after a series of work-ups. After treatment with low-molecular-weight heparin, deep vein thrombosis improved. Serum homocysteine level returned to normal after folic acid and vitamin B12 supplementation for 2 months. After therapy with four-combined anti-tuberculosis drugs for 9 months, the pulmonary tuberculosis subsided. In the present case report, the cause of hyperhomocysteinemia may be related to folic acid deficiency and chronic renal insufficiency.