Homocysteine levels in patients treated with lipid apheresis: effect of a vitamin therapy

Background Patients treated with lipid apheresis already suffer from famili al hypercholesterolemia and severe coronary heart disease: any additional r isk factor is dangerous for these patients. Hyperhomocysteinemia has been r ecognized as an independent risk factor for atherosclerotic disease. We che cked the frequency of hyperhomocysteinemia in lipid apheresis patients and measured the effect of a vitamin therapy. Materials and Methods Sixteen heterozygous patients (10 males, 6 females) w ere studied, who were being treated by three different apheresis procedures . Homocysteine was measured using an enzyme conversion immunoassay. Cystath ionine and methylmalonic acid were assessed by gas chromatography/mass spec trometry. Serum levels of folic acid, vitamin B12, and vitamin B6 were also determined. The patients received a vitamin therapy (3 mg folate, 60 mug c yanocobalamine, 10 mg pyridoxine hydrochloride daily) for 12 weeks. Results In 9 out of 16 patients, plasma homocysteine levels were found to b e elevated (> 12 mu mol L-1). Cystathionine concentrations were also increa sed, especially in those patients with elevated homocysteine. Methylmalonic acid levels were not elevated. Serum folic acid, vitamin B6, and vitamin B 12 concentrations were initially in the normal range and not correlated to plasma homocysteine. The vitamin therapy reduced the plasma homocysteine co ncentrations in all patients significantly by 33%. Among those patients wit h elevated homocysteine levels, the optimal range < 12 <mu>mol L-1 for homo cysteine was rarely reached. Conclusions In patients treated with lipid apheresis, a hyperhomocysteinemi a can be frequently seen. The constellation of both elevated homocysteine a nd cystathionine levels points to the existence of tissue vitamin deficienc ies, folate and vitamin B-6, which were improved by vitamin supplements. Be cause methylmalonic acid was mostly normal, a vitamin B-12 deficiency was n ot proven.