LOINC display name : IgM.intrathecally synthesized/Total IgM (CSF) [Mass fraction];
LOINC long common name : IgM.intrathecally synthesized/IgM.total in Cerebral spinal fluid;
LOINC short name : IgM.IT/IgM.total MFr CSF;
LOINC description : Note that both the numerator and denominator are concentration of the same protein
in the CSF, ..BUT the denominator is the total CSF concentration and the numerator
is the contribution of the protein in the CSF that is MADE IN THE CSF (i.e. intrathecally)
---as opposed to protein that has diffused in from the blood. The calculation is IgX(Intracthecal
fraction) [IgX(Intrathecally synthsized concentration)/IgX(Total CSF Concentration)]*100
from Multiple Sclerosis (1998) 4, 111 - 117 From the same paper, the IgX(Intrathecally
synthsized concentration) is complex to determine, but is based on the amount of protein
in the CSF over and above that of the normal upper limit expected in the CSF (compared
to that in blood). That 'over and above' amount is what is deemed to be produced in
the CSF, which is the Intrathecal Fraction...... Same theme repeats in other papers
(e.g. Am. J. Trop. Med. Hyg., 82(6), 2010, pp. 1094-1098);
Has component