High Sensitivity New Parameters for the Detection of Vitamin B12 and Folate Deficiencies

The classical flow charts used widely for the diagnostic approach of anemia due to Vitamin B12 (B12) deficiency or Anemia due Folate deficiency includes the Mean cell Volume of the red blood cells (MCV) as one of the key tests for the suspicion of these diseases and the differential diagnosis of anemia. In our experience, only around half of the patients with B12 deficiency (B12) or Folate deficiency have high MCV, in many of the situations because the coexistence of other causes of anemia. The majority of the actual hematology analyzers provide information about Red cell size (MCV), Reticulocyte Volume (MRV) and Platelet Volume (MPV) Recent hematology instruments provide research data about the size of some of the White Blood Cells (WBC) as the LH700 Series from Beckman Coulter We designed a study to find which tests can help to improve the detection/flagging of these deficiencies. We collected blood samples from 58 individuals that came to the hospital and were considered as normals by the physicians. We collected 108 cases with anemia defined according the WHO anemia criteria (Hb<12 g/dL in women and Hb<13 g/dL in men.) from the hospital laboratory samples. The WHO criteria of anemia was the only condition considered. After this, samples were randomly selected from the anemic patients. We analyzed in both groups the CBC-Diff, the reticulocyte %, # and Reticulocyte related parameters, WBC Research Population Data, Serum Iron, Serum Ferritin, B12, Serum Folate, RBC Folate, Serum EPO, Transferrin, CRP, and Intrinsic Factor Antibody and checked the efficiency of the hematological parameters and research data (Mean Volume of Neutrophils and Monocytes) to detect the presence of B12 deficiency, Folate deficiency or both. We have compared B12 and Folate deficiencies with normals and also with the rest of anemias, looking for the different cut-off values in both situations. We also studied two patients with Serum B12 and Serum Folate deficiencies respectively, and followed over time the evolution of the previous tests listed above after a successful treatment.

The study population included 82 males (49.4%) and 84 females (50.6%). We found that 5,2 % of the “normal” patients with normal Hemoglobin have B12 deficiency (B12 < 145 pg/mL) 5.2 % of the “normal” with normal Hemoglobin have intermediate values of B12 (B12 > 145 <180 pg/mL) and 3.45 % of the “normal” have low serum Folate. From the group of anemic patients, we found that the prevalence of B12 deficiency was 21/108= 19.4%, the prevalence of intermediate B12 was 3/108= 2.8%, the prevalence of serum folate deficiency was 10/108= 9.3%, and there were two cases with serum folate deficiency that also have respectively B12 deficiency (1/108= 0.9%) or B12 in intermediate values (1/108= 0.9%)

The analytical sensitivity/sensitivity/cutoffs are specific for this study only.

The @Mean Neutrophil Volume (@MNE V) and @Mean Monocyte Volume (@MMOV) may be used for the detection of megaloblastic neutrophils and monocytes. Megaloblastic Neutrophils and Megaloblastic monocytes may be seen in Megaloblastic anemias due to B12 and/or folate deficiency. MNEV and MMOV have significantly higher sensitivity than the previous information from the red cells (MCV) detecting B12 or folate deficiency because they are not affected by the presence at the same time of Iron deficiency or other reasons of anemia. @ Research use only parameters