1 research outputs found
Immunoglobulin heavy/light chain analysis enhances the detection of residual disease and monitoring of multiple myeloma patients
Aim To evaluate the clinical utility of incorporating a novel
heavy/light chain immunoassay (HLC) into the existing
methods for the assessment of multiple myeloma (MM)
patients.
Methods Convenience sera samples from 90 previously
treated IgG and IgA MM patients in different disease stages
were analyzed. The study was conducted in Clinical Hospital
Center Zagreb between 2011 and 2013. The collected
sera were analyzed by standard laboratory techniques (serum
protein electrophoresis, quantification of total immunoglobulins,
serum immunofixation, serum free light chain
[FLC] assay) and HLC assay.
Results HLC ratios outside the normal range were found
in 58 of 90 patients, including 28 out of 61 patients with
total immunoglobulin measurements within the normal
range and 5 out of 23 patients in complete response. Both
elevated HLC isotype level and abnormal HLC ratio correlated
with the parameters of tumor burden, including
percentage of plasma cells in the bone marrow (P < 0.001
and P = 0.002, respectively) and an abnormal serum FLC ratio
(for both P < 0.001). In addition, abnormal HLC isotype
level correlated with serum beta-2-microglobulin level
(P = 0.038). In terms of prognosis, abnormal HLC isotype
level and abnormal HLC ratio were significantly associated
with shorter overall survival (P < 0.001 and P = 0.002,
respectively). Interestingly, suppression of the uninvolved
(polyclonal) isotype pair, but not other non-myeloma immunoglobulin
isotypes, was also associated with a shorter
overall survival (P = 0.021). In a multivariate analysis, an
abnormal HLC ratio and Ī²2-microglobulin level >3.5mg/L
were independent risk factors for survival.
Conclusion The new HLC assay has greater sensitivity in
detecting monoclonal protein, correlates with tumor burden
markers, and affects patientsā outcome