Modulation of serum gastric parietal cell antibody level by levamisole and vitamin B12 in oral lichen planus

Objectives: The objective of this study was to test the efficacy of three different treatment modalities on the reduction of serum anti-gastric parietal cell autoantibody (GPCA) level in GPCA-positive oral lichen planus (OLP) patients.Materials and methods: Of 147 GPCA-positive OLP patients, 100 were treated with levamisole plus vitamin B12, 10 with vitamin B12 only and 37 with levamisole only. The serum GPCA levels in 147 OLP patients were measured at baseline and after treatment.Results: Treatment with levamisole plus vitamin B12 for a period of 2-50 months and treatment with vitamin B12 only for a period of 4-44 months could effectively reduce the high serum GPCA level to undetectable level in 100 and 10 OLP patients, respectively. However, treatment with levamisole only for a period of 2-50 months could not modulate the high mean serum GPCA titer to a significantly lower level in 37 OLP patients. A 92% GPCA recurrence rate was found in 25 OLP patients receiving no further vitamin B12 treatment during the GPCA-negative remission period.Conclusion: For GPCA-positive OLP patients, treatment modality containing vitamin B12 can effectively reduce the high serum GPCA level to undetectable level. OLP patients with underlying autoimmune atrophic gastritis trait should receive a maintenance vitamin B12 treatment for life.