Prevalence of vitamin B12 deficiency in patients with plasma cell dyscrasias: a retrospective review.
BACKGROUND
To the authors' knowledge, the prevalence of vitamin B12 deficiency among patients with plasma cell dyscrasias (PCD) is largely unknown. Identifying this vitamin deficiency in such patients could help improve their anemia and increase their tolerance to potentially neurotoxic agents.


METHODS
The authors retrospectively reviewed the charts and laboratory results of 664 consecutive patients diagnosed with PCD who had their vitamin B12 and folate status evaluated between 1997 and 2001 at the Cleveland Clinic Multiple Myeloma Research Program. The patients were screened for vitamin B12 deficiency using serum vitamin B12 and methylmalonic acid.


RESULTS
Of the 664 patients whose medical charts were reviewed, information on vitamin B12 status was available for 522 patients (78%). Among these 522 patients, 71 (13.6%) had laboratory-defined vitamin B12 deficiency and the remaining 451 patients (86.4%) did not. On univariate analysis, vitamin B12 deficiency correlated with immunoglobulin A (IgA) PCD (P = 0.04), higher mean corpuscular volume (P = 0.008), and longer follow-up (P = 0.048). In a covariate adjusted model, only the presence of IgA PCD was associated with an increased prevalence of vitamin B12 deficiency (P = 0.003).


CONCLUSIONS
Vitamin B12 deficiency was prevalent in patients with PCD, especially in patients with the IgA subtype. Serum vitamin B12 measurements should be part of the initial evaluation and subsequent workups for anemia in patients with PCD.
Internal Medicine Residency Program, The Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA.
Rachid
R
Baz
Carlos
C
Alemany
Ralph
R
Green
Mohamad A
MA
Hussein
D000328:Adult; D000368:Aged; D000740:Anemia / Q000209:etiology / Q000517:prevention & control; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis; D008297:Male; D008875:Middle Aged; D010265:Paraproteinemias / Q000150:complications* / Q000188:drug therapy; D010347:Patient Care Planning; D015995:Prevalence; D012189:Retrospective Studies; D014806:Vitamin B 12 Deficiency / Q000150:complications / Q000453:epidemiology*
D007070:Immunoglobulin A