The pathogenesis of decreased GOT and GPT activity in the plasma of hemodialysis patients

The role of vitamin B₆ deficiency

Abstract

The mechanisms responsible for the low plasma (p) GOT and GPT activity in hemodialysis (HD) patients remain elusive. This prospective study was undertaken to clarify the relationship between pGOT, pGPT and pyridoxal-5'-phosphate (PLP) levels (active form of vitamin B₆) in these patients. A group of 52 HD patients were given oral pyridoxine HCl, 30mg daily, for 5 weeks. Prior to supplementation (Day 0), 17 (33%) of the 52 patients had deficient pPLP levels (Group 1) while the remaining 35 patients had normal pPLP levels (Group 2). Positive correlations were noted between pPLP and both pGOT (r=0.57, p<0.01) and pGPT (r=0.68, p<0.01). The mean pGOT (9.2±0.3: Mean±SEM) and pGPT (8.3±0.7) levels were markedly lower in Group 1 (p<0.05) than in Group 2 (13.4±0.7, 11.4±0.9, respectively). These low pGOT and pGPT levels increased to those seen in Group 2, in which no change from basal values was seen despite vitamin B₆ supplementation (Day 35). The administration of vitamin B₆ resulted in a significant increase in pPLP in both groups (Day 35) but pPLP dropped to subnormal levels in 5 patients in Group 1 and 7 of those in Group 2 three months after supplementation was discontinued (Day 125). The mean pGOT and pGPT of these pPLP deficient patients became lower than those of the remaining 40 patients with normal pPLP values (p<0.05).
In conclusion, low pGOT and pGPT levels in HD patients are in part due to a deficiency of pPLP which serves as a coenzyme for these transaminases. The low pPLP, pGOT and pGPT levels can be restored by vitamin B₆ (pyridoxine HCl) supplementation.