Relationships between low serum cobalamin concentrations and methlymalonic acidemia in cats.
BACKGROUND
Serum cobalamin concentrations below reference range are a common consequence of gastrointestinal disease in cats. Serum cobalamin <or= 100 ng/L is associated with methylmalonic acidemia.


OBJECTIVE
To determine the prevalence of cobalamin deficiency, defined by elevated serum methylmalonic acid (MMA), in cats with serum cobalamin <or= 290 ng/L, and the optimum serum cobalamin concentration to predict cobalamin deficiency in cats. SAMPLE SET: Residual serum samples (n = 206) from cats with serum cobalamin <or= 290 ng/L.


METHODS
Retrospective, observational study. Serum cobalamin and folate were measured with automated assays. Serum MMA was determined by gas chromatography-mass spectrometry. Cobalamin deficiency was defined as serum MMA > 867 nmol/L. Sensitivity and specificity of serum cobalamin concentrations <or=290 ng/L for detecting MMA > 867 nmol/L were analyzed using a receiver-operator characteristic curve.


RESULTS
There was a negative correlation between serum cobalamin and MMA concentrations (Spearman's r=-0.74, P < 0.0001). The prevalence of MMA >or= 867 nmol/L in cats with serum cobalamin <or= 290 ng/L was 68.4%. Serum cobalamin <or= 160 ng/L had a 74% sensitivity and 80% specificity for detecting MMA > 867 nmol/L. No significant difference in serum folate concentrations was detected between affected and unaffected cats.


CONCLUSIONS
Elevated MMA concentrations, suggesting cobalamin deficiency, are common in cats with serum cobalamin <or= 290 ng/L. Cobalamin deficiency is clinically significant, and supplementation with parenteral cobalamin is recommended for cats with gastrointestinal disease and low serum cobalamin concentrations.
Ruaux
C G
CG
Gastrointestinal Laboratory, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA. craig.ruaux@oregonstate.edu
Steiner
J M
JM
Williams
D A
DA
D000818:Animals; D002371:Cat Diseases / Q000097:blood*; D002415:Cats; D008764:Methylmalonic Acid / Q000097:blood*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014805:Vitamin B 12 / Q000097:blood*; D014806:Vitamin B 12 Deficiency / Q000097:blood / Q000662:veterinary
D008764:Methylmalonic Acid; D014805:Vitamin B 12