LOINC display name : IgM clearance/Albumin clearance (S CSF) [Ratio];
LOINC long common name : IgM clearance/Albumin clearance [Ratio] in Serum and CSF;
LOINC short name : IgM/Alb clear Ser CSF-Rto;
LOINC description : CSF IgM, IgA, and IgG indexes are indicators of intrathecal immunoglobulin synthesis.
The calculations incorporate the CSF-serum albumin quotient, an indicator of blood-brain-barrier
(BBB) function, in order to differentiate whether the immunoglobulins found in the
CSF were produced intrathecally or leaked across the BBB. These immunoglobulin indexes
can be useful in the diagnosis of central nervous system infections, neoplasms and
primary neurologic diseases such as multiple sclerosis. They also have the potential
to monitor treatment efficacy in conditions such as systemic lupus erythematosus with
CNS involvement, in which one study found that all three indexes decreased significantly
along with CNS symptoms during successful treatment. The CSF IgM index is calculated
as (CSF IgM/serum IgM)/(CSF albumin/serum albumin), which can also be represented
as (CSF IgM x serum albumin)/(serum IgM x CSF albumin). [PMID: 3899036];
Has component