In order to discriminate between transsudated and intrathecally produced IgA and IgM in patients with blood cerebrospinal fluid (CSF) barrier (BCB) damage, we developed extended indices (IgA-EI and IgM-EI) for these immunoglobulins according to the general formula for extended index of a component X in CSF:
where a is a parameter specific for X. For IgA parameter a was found to be 1·15 and for IgM 1·9.
A preliminary evaluation of IgA-EI and IgM-EI indicated lower false positive rates as compared to CSF IgA and IgM concentrations as well as ‘conventional’ IgA and IgM indices in cases with BCB damage, and essentially the same rates as for the hyperbolic formulae of Reiber and Felgenhauer.
The importance of reliable sampling and analytical technique for IgM in CSF is discussed.
MehtaPDDiagnostic usefulness of cerebrospinal fluid in multiple sclerosis. Crit Rev Clin Lab Sci1991; 28: 233–51
2.
ÖhmanSForsbergPNelsonNVrethemMAn improved formula for the judgement of intrathecally produced IgG in the presence of blood brain barrier damage. Clin Chim Acta1989; 181: 265–72
3.
ÖhmanSErnerudhJForsbergPHenrikssonAvon SchenckHVrethemMComparison of seven formulae and isoelectrofocusing for determination of intrathecally produced IgG in neurological diseases. Ann Clin Biochem1992; 29: 405–10
ErnerudhJOlssonTBerlinGvon SchenckHCerebrospinal fluid immunoglobulins and β2-microglobulin in lymphoproliferative and other neoplastic diseases of the central nervous system. Arch Neurol1987; 44: 915–20
8.
ReiberHFelgenhauerKProtein transfer at the blood cerebrospinal fluid barrier and the quantitation of the humoral immune response within the central nervous system. Clin Chim Acta1987; 163: 319–28
9.
ShariefMKKeirGThompsonEJIntrathecal synthesis of IgM in neurological diseases: a comparison between detection of oligoclonal bands and quantitative estimation. J Neurol Sci1990; 96: 131–42
10.
ForsbergPHenrikssonALinkHÖhmanSReference values for CSF-IgM, CSF-IgM/S-IgM ratio and IgM index, and its application to patients with multiple sclerosis and aseptic meningoencephalitis. Scand J Clin Lab Invest1984; 44: 7–12
11.
AsburyAKArnasonBGWKarpHRMcFarlinDECriteria for diagnosis of Guillain-Barré syndrome. Ann Neurol1978; 3: 565–6
FisherMAn unusual variant of acute idiopathic polyneuritis (syndrome of ophthalmoplegia, ataxia and areflexia). New Engl J Med1956; 255: 57–65
14.
RoseASEllisonGWMyersLWTourtellotteWWCriteria for the clinical diagnosis of multiple sclerosis. Neurology1976; 26: 20–2
15.
SolbergHEApproved recommendations (1987) on the theory of reference values. Part 5. Statistical treatment of collected reference values. Determination of reference limits. Clin Chim Acta1987; 170: S13–S32
ShariefMKPhilMThompsonEJThe predictive value of intrathecal immunoglobulin synthesis and magnetic resonance imaging in acute isolated syndromes for subsequent development of multiple sclerosis. Ann Neurol1991; 29: 147–51
18.
ShariefMKThompsonEJIntrathecal immunoglobulin M synthesis in multiple sclerosis. Brain1991; 114: 181–95
19.
SindicCJMDelacroixDLVaermanJPLaterreECMassonPLStudy of IgA in the cerebrospinal fluid of neurological patients with special reference to size, subclass and local production. J Neuroimmunol1984; 7: 65–75
20.
LolliFHalawaILinkHIntrathecal synthesis of IgG, IgA, IgM and IgD in untreated multiple sclerosis and controls. Acta Neurol Scand1989; 80: 238–47
21.
LinkHBaigSKostulasVOlssonOOlssonTImmunoglobulin-secreting cells in the cerebrospinal fluid from patients with muscular tension headache. J Neuroimmunol1989; 25: 1–6
22.
FelgenhauerKProtein size and cerebrospinal fluid composition. Klin Wschr1974; 52: 1158–64
