hydroxocobalamin and Achlorhydria

Ten cases of pernicious anaemia seen over a 15-year period (1973-1988) in a Lagos hospital are presented. Their ages ranged from 34 to 67 with a mean of 53.6 years. Females outnumbered males 6 to 4. Complications seen include gastric carcinoma, myelopathy, peripheral neuropathy, skin hyperpigmentation, hair depigmentation and diarrhoea. Reluctance to consider the diagnosis owing to firmly held notions of its rarity and a penchant for empirically treating chronic anaemias with all available haematinics and blood transfusion are probably contributory to its underdiagnosis. The fact that seven of the patients presented were seen in the last three years and three of them in the last one year raises the possibility of an increasing incidence of pernicious anaemia in Africans. The disease may be much less rare in Africans than once believed, and medical education should emphasize its existence and advocate greater care in the management of chronic anaemias.

Topics: Achlorhydria; Adult; Aged; Anemia, Pernicious; Autoantibodies; Autoimmune Diseases; Bone Marrow; Diagnosis, Differential; Fatigue; Female; Humans; Hydroxocobalamin; Incidence; Intrinsic Factor; Male; Middle Aged; Nigeria; Peripheral Nervous System Diseases; Pigmentation Disorders; Psychophysiologic Disorders; Retrospective Studies; Vitamin B 12; Vitamin B 12 Deficiency

Five patients presenting clinically with a form B12-deficiency neuromyelopathy, with cord involvement in all and proximal muscle weakness in two of them, were investigated for their neurologic, hematologic and vitamin status. Megaloblastosis and achlorhydria were present in all, and impaired absorption of 57Co vitamin B12 and of D-xylose was detected in four. Total cyanide extracted vitamin B12 (A) was lowered in all cases and noncyanide extractable (B) in four of the five, being zero in three. All five responded to injections of hydroxocobalamin. In two patients sequential estimations showed that both A and B, especially the latter, rose steeply initially, normalizing at 50% of A after some weeks. Moiety B is suggested to be physiologically the more active and dissociable form of vitamin B12. Markedly elevated initial serum folate levels, and their subsequent fall under treatment with B12, indicated the operation of the "methyltetrahydrofolate trap". Blood levels of thiamin, nicotinic acid and pantothenic acid were within normal limits. However, serum riboflavin (B2) total vitamin B6 and pyridoxal were reduced in all where tested. Vitamin B6 deficiency could have resulted from its own malabsorption and have contributed to be B12 deficiency. Vitamin B2 and B6 levels also corrected themselves on B12 therapy. The B-vitamin deficiencies in our patients probably resulted from intestinal malabsorption, with a possible factor of malnutrition consequent to their strictly vegetarian diet.

Topics: Achlorhydria; Adolescent; Adult; Animals; Demyelinating Diseases; Diet, Vegetarian; Erythrocyte Count; Humans; Hydroxocobalamin; Malabsorption Syndromes; Male; Megaloblasts; Milk; Spinal Cord Diseases; Vitamin B 12 Deficiency; Vitamin B 6 Deficiency; Vitamin B Complex