[Assessment of laboratory findings in megaloblastic anemia--measurement of serum vitamin B12 and methylmalonic acid].Rinsho Ketsueki. 1989 Jan; 30(1):36-44.RK
The laboratory findings of 20 patients with untreated megaloblastic anemia due to vitamin B12 deficiency were analysed. The material consists of 13 patients with pernicious anemia, 6 with postgastrectomy B12 deficiency and one with malabsorption syndrome. Hematological data (RBC, Hgb, Ht, WBC, Plt) were correlated with each other and serum LDH levels. Megaloblastic changes of bone marrow were apparent in cases of which Hgb values were below 9 g/dl, although its change were not clear in cases with mild anemia (above 9 g/dl). However, giant metamyelocytic changes of bone marrow were seen even in cases with mild anemia. Serum B12 levels in 6 out of 19 cases (31.6%) measured by clinical laboratory center were within normal range. In contrast, its level in all cases measured by radiodilution assay using R-protein or intrinsic factor were lower than normal values. Serum B12 levels measured by the latter method were correlated with various hematological data and also related with hematological severity, although its level measured by clinical laboratory did not have any correlation with hematological data. Schilling test seemed to be unreliable, because sample volume which was suggested by kit manual was too small (2 ml) to catch enough radioactivity for accurate measurement. Serum methylmalonic acid levels measured by gas capillary mass spectrophotometry were higher than normal values in all cases and were well correlated with hematological data.