Elevated Vitamin B12 Levels in Myeloproliferative Neoplasm (MPN) Patients: A Potential Diagnostic and Prognostic Marker.

BACKGROUND

Elevated vitamin B12 (B12) levels are linked to an increased risk of cancers, including hematological malignancies. This study focuses on the relationship between elevated B12 and myeloproliferative neoplasms (MPNs): Polycythemia Vera (PV), Primary Myelofibrosis (MF), Essential Thrombocytosis (ET), and Chronic Myeloid Leukemia (CML). Elevated B12 in MPNs is believed to arise from increased transcobalamin I (TCI) secretion by proliferating leukocytes, leading to higher serum levels. B12 may serve as a diagnostic and prognostic biomarker for these conditions. However, its sensitivity, specificity, and cutoff levels are unclear.

AIM

To assess the prevalence of high B12 levels in MPN patients, determine the median levels, identify a diagnostic cutoff, and evaluate the sensitivity and specificity of B12 as a marker.

METHODS

Data were retrieved from the National Center for Cancer Care and Research in Doha, Qatar, for MPN patients from January 2016 to December 2022.

RESULTS

A total of 467 patients were included: 232 with CML, 98 with PV, 88 with ET, and 50 with MF. The majority were male (66%) and of Asian origin (56%), with a median age of 48.7 years. CBC results showed median hemoglobin of 9.2 g/dL, WBC count of 73 x 10^3/uL, and platelet count of 531 x 10^3/uL. Elevated B12 levels were found in 95 patients (20%): 71% CML, 14% PV, 10% MF, and 5% ET. Extreme elevations were seen in 59 patients. The mean B12 level decreased from 747.3 ± 686.5 pg/mL before treatment to 397.9 ± 343.7 pg/mL after one year (p=0.01). Median levels were 458 pg/mL (718) before treatment and 301 pg/mL (229) after. In the extreme high B12 group, the mean was 1722 pg/mL before and 677 pg/mL after treatment.

CONCLUSION

Elevated B12 levels are associated with disease activity in CML. However, their role as a reliable marker for disease monitoring remains uncertain, and further studies are needed to confirm their utility for CML progression.