Suppression of alternative immunoglobulin pairs correlates with the MGUS risk degree more significantly than suppression of polyclonal immunoglobulin levels - Partial results from HevyLiteTM examination in MGUS
Abstract
Monoclonal gammopathy of undetermined significance(MGUS) indicates an asymptomatic and potentially malignant state characterised by benign clonal proliferation of plasma cells secerning discharging) monoclonal immunoglobulin(MIG, M-protein) detectable in serum and/or urine in the absence of malignant lymphocyte proliferation.It has been observed that in some patients,MGUS transforms into one of the malignant forms of monoclonal gammopathy.The wellknown factors determining the risk degree of progression include in particular the quantity, M-protein type and the ratio of immunoglobulin free light chains (FLC) allowing the efficient stratification of MGUS patients. In addition, several authors consider the present suppression of polyclonal immunoglobulin levels to be a potential factor of progression.The study aimed at conducting a pilot analysis of levels of immunoglobulin heavy/light chains pairs(HLC) in a group of MGUS patients and at comparing the results with the M-protein levels detected by gel electrophoresis.Furthermore,the polyclonal immunoglobulin levels and the levels of HLC alternative pairs were to be compared with a view to verify the degree of immune paresis depending on the MGUS risk degree.The analysed set comprised 148 serum samples of MGUS patients who were stratified into 4 risk groups, according to the levels,M-protein type and FLC index values.FLC levels,polyclonal immunoglobulin levels and HLC levels were determined by means of the SPA Plus turbidimeter platform.In the statistical analysis,Spearmans rank correl. and Mann-Whitney U Test with Bonfer. correction were applied.The analysis confirmed a very close correlation between M-protein levels and HLC determination which appears to be an auxiliary or alternative method of M-protein determination with an advantage in case of atypical electrophoresis results or by very low M-protein concentrations with the benefit of Igκ/Igλ index calculation.