Methylmalonic Acid LC-MS

Intended purpose
The LC-MS/MS kit is intended for the determination of Methylmalonic Acid in serum/plasma/urine. The components in the kit must be used as stated in the user manual.

Summary
Methylmalonic acid is an organic acid of which the blood levels are usually raised in case of a B12 deficiency. Adenosylcobalamin – one of the two active forms of B12 – is a cofactor of the enzyme L-methylmalonyl-CoA- mutase, which converts L-methylmalonyl-Coa into succinyl-CoA. If adenosylcobalamin is lacking, excess D-methylmalonyl-CoA (precursor of L-methylmalonyl-CoA) is converted into methylmalonic acid (MMA) which causes raised blood levels of MMA. In short: a B12 deficiency (usually) causes high MMA.

High MMA serum values are also found in people with renal insufficiency, hypovolemia (decreased volume of circulating blood) and intestinal bacterial overgrowth. In these cases MMA levels cannot be used to diagnose B12 deficiency though a B12 deficiency might simultaneously exist. In the case of kidney disease (or hypovolemia) MMA levels in urine can be tested.

MMA values can be false-normal in people with B12 deficiency who take (or recently took) antibiotics, for these destroy the intestinal flora needed to make propionic acid (an organic acid, precursor to MMA). MMA should be tested before starting treatment.

In case of a B12 deficiency treatment will rather quickly lower MMA levels. Testing sometime after starting treatment, for instance after one or two months, may serve as a confirmation of the B12 deficiency diagnosis. This can also be done when people before treatment have a MMA value which is not distinctly above reference values.

The determination of MMA can be performed from serum, plasma and urine. Serum samples are generally used for MMA determination, as this matrix is used for parallel cobalamin level tests. The advantage of determination from serum therefore is the sample availability. Furthermore nutrition seems to have less influence on the MMA serum level than in case with urine. For determination in urine additional measurement of creatinine is also necessary.

Mass spectrometry based methods have been widely tested for the determination of Methylmalonic Acid. Furthermore chromatographic separation from the structural isomer Succinic Acid (SA) is critical and not elementary. This method can be used for the routine analysis of Methylmalonic Acid in human serum, plasma and urine. Sample preparation is simple and rapid. A six-point lyophilized serum calibrator at clinically relevant levels has been added to the kit. An isotope-labelled internal standard (Methylmalonic Acid D3) is added to compensate for matrix effects and measurement variations.

Manufactured by Diagnotix; Distributed by Tecan, IBL International GmbH.

For concrete data please consult the Instruction for Use in the download box on the top right side.

For concrete data please consult the Instruction for Use in the download box on the top right side.