Role of LDH levels in differentiating anemias

Background: There is a need to differentiate megaloblastic anemia from mixed deficiency anemia as both require different management protocols. With the acquisition of more information about them, tests such as serum vitamin estimation and Schilling test, were found to have their limitations. Hence there is a need to search newer diagnostic candidates to differentiate between megaloblastic anemia and mixed deficiency anemia. Aims and Objective: The current study was undertaken to find usefulness of serum Lactate Dehydrogenase (LDH) in differentiating megaloblastic anemia from mixed deficiency anemia. Materials and Methods: 100 patients were included in the study. Blood smears were stained and analysed. Complete blood counts were performed. Bone marrow examination was done, where needed. Biochemical tests were performed for estimation of vitamin B12, Folate and for LDH. Results: Out of the 100 cases 51 were diagnosed as megaloblastic anemia and 49 were diagnosed as mixed deficiency anemia. The LDH levels were significantly higher in cases of megaloblastic anemia as compared to mixed deficiency anemia. Conclusion: Serum LDH levels can be used in differentiating megaloblastic anemia from mixed deficiency anemia.

Identification of a 4-base deletion in the gene in inherited intrinsic factor deficiency

A 4-base deletion has been identified in the coding region of the gene for gastric intrinsic factor (IF) in an 11-year-old girl with severe anemia and cobalamin (Cbl) deficiency. The bone marrow showed frank megaloblastic morphology, and the Schilling test indicated a failure to absorb Cbl that was corrected by coadministration of IF. Pentagastrin administration induced acid secretion, but the gastric juice lacked IF as determined by CbI binding, by fractionation of protein-bound CbI, and by immunoprecipitation with anti-IF antiserum. Individual exons were amplified by the polymerase chain reaction by using primers to the flanking intronic regions, and the nucleotide sequence analysis identified a 4-base deletion (c183_186delGAAT) spanning positions 104 to 107 in exon 2, resulting in premature termination of translation. This mutation also eliminates a site for Bst XI endonuclease and introduces a site for BsaBI for identifying this deletion in hereditary IF deficiency.

Ischemic strokes secondary to vitamin B12 deficiency-induced hyperhomocystinemia

A 45-year-old woman sustained two ischemic cerebral infarctions 16 years after ileal resection for Crohn's disease. Her evaluation showed an elevated random serum homocystine level, a low serum vitamin B12 level, and an increased mean corpuscular volume (MCV) without anemia. A methionine-loading test resulted in a marked increase in the homocystine levels 2, 4, and 6 hours after the load. A Schilling test demonstrated a malabsorption of vitamin B12. Vitamin B12 injections normalized her fasting homocystine level and her MCV. She has had no recurrent strokes during a year follow-up.

Prospective evaluation of protein bound vitamin B12(cobalamin) malabsorption in the elderly using trout flesh labelled in vivo with 57Co-cobalamin

Background—The frequency of dietary protein bound vitamin B12 malabsorption in elderly patients remains controversial.Aims—To evaluate this malabsorption in elderly hospitalised patients using a modified Schilling test.Patients—Fourteen elderly patients with low B12 blood levels were prospectively selected from 394 hospitalised patients.Methods—The modified Schilling test was performed with trout labelled in vivo.Results—The test was normal in five healthy elderly subjects, in 7/8 patients with pancreatic insufficiency, and in nine non-elderly patients with antral gastritis. The low decision limit was established at 3.3% (median 4.8%). From the 14 elderly patients with low B12 prospectively selected from 394 hospitalised patients, seven had a real deficiency with anaemia and an increased homocysteine and/or methylmalonate serum level. The modified Schilling test showed malabsorption in five of these patients, including two in which the standard Schilling test was normal, and three in which the standard Schilling test was partially corrected by an intrinsic factor.Conclusions—Protein bound vitamin B12malabsorption was detected in at least 0.5% of elderly hospitalised patients, using the labelled trout flesh absorption test.