Does serum gastric parietal cell antibody titer have influence on anemia and vitamin B12 deficiency in atrophic glossitis patients?

Background/Purpose: Our previous study found 284 gastric parietal cell antibody (GPCA)-positive atrophic glossitis (AG) patients (so-called GPCA⁺AG patients in this study) in a group of 1064 AG patients. This study evaluated whether high-titer (GPCA titer ≥ 160) GPCA⁺AG patients had greater frequencies of anemia, vitamin B12 deficiency, macrocytosis, and hyperhomocysteinemia than low-titer (GPCA titer < 160) GPCA⁺AG patients. Methods: Complete blood count, serum iron, vitamin B12, folic acid, homocysteine, and GPCA levels in 117 high-titer GPCA⁺AG patients, 167 low-titer GPCA⁺AG patients, and 532 healthy control subjects were measured and compared. Results: We found that 12.0%, 29.1%, 23.1%, 16.2%, 1.7%, and 23.1% of 117 high-titer GPCA⁺AG patients and 5.4%, 17.4%, 17.4%, 7.2%, 1.2%, and 14.4% of 167 low-titer GPCA⁺AG patients were diagnosed as having macrocytosis, blood hemoglobin, iron, vitamin B12, and folic acid deficiencies, and hyperhomocysteinemia, respectively. Moreover, both 117 high-titer and 167 low-titer GPCA⁺AG patients had significantly greater frequencies of macrocytosis, blood hemoglobin, serum iron and vitamin B12 deficiencies, and hyperhomocysteinemia than 532 healthy control subjects (all P-values < 0.05). In addition, 117 high-titer GPCA⁺AG patients also had greater frequencies of anemia (P = 0.029, statistically significant), serum vitamin B12 deficiency (P = 0.027, statistically significant), macrocytosis (P = 0.075, marginal significance), and hyperhomocysteinemia (P = 0.085, marginal significance) than 167 low-titer GPCA⁺AG patients. Conclusion: For GPCA⁺AG patients, high-titer GPCA⁺AG patients have greater frequencies of anemia, serum vitamin B12 deficiency, macrocytosis, and hyperhomocysteinemia than low-titer GPCA⁺AG patients.