Original scientific paper
https://doi.org/10.3325/cmj.2015.56.263
Immunoglobulin heavy/light chain analysis enhances the detection of residual disease and monitoring of multiple myeloma patients
Josip Batinić
; School of Medicine, University of Zagreb, Zagreb, Croatia
Zinaida Perić
; School of Medicine, University of Zagreb, Zagreb, Croatia
Dragana Šegulja
; University Hospital Center Zagreb, Department of Laboratory Diagnostics, Clinical Unit of Special Biochemistry, Zagreb, Croatia
James Last
; The Binding Site Group Ltd, Birmingham, UK
Sanja Prijić
; University Hospital Center Zagreb, Department of Laboratory Diagnostics, Clinical Unit of Cellular Immunodiagnostics and In Vitro Procedures, Zagreb, Croatia
Klara Dubravčić
; University Hospital Center Zagreb, Department of Laboratory Diagnostics, Clinical Unit of Cellular Immunodiagnostics and In Vitro Procedures, Zagreb, Croatia
Lidija Volarić
; University Hospital Center Zagreb, Department of Laboratory Diagnostics, Clinical Unit of Special Biochemistry, Zagreb, Croatia
Dubravka Sertić
; University Hospital Center Zagreb, Department of Internal Medicine, Division of Hematology, Zagreb, Croatia
Ivo Radman
; University Hospital Center Zagreb, Department of Internal Medicine, Division of Hematology, Zagreb, Croatia
Sandra Bašić-Kinda
; University Hospital Center Zagreb, Department of Internal Medicine, Division of Hematology, Zagreb, Croatia
Danica Matišić
; University Hospital Center Zagreb, Department of Laboratory Diagnostics, Clinical Unit of Special Biochemistry, Zagreb, Croatia
Drago Batinić
; University Hospital Center Zagreb, Department of Laboratory Diagnostics, Clinical Unit of Cellular Immunodiagnostics and In Vitro Procedures, Zagreb, Croatia
Boris Labar
; School of Medicine, University of Zagreb, Zagreb, Croatia
Damir Nemet
; School of Medicine, University of Zagreb, Zagreb, Croatia
Abstract
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 β2-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 patients’ outcome.
Keywords
Hrčak ID:
151298
URI
Publication date:
15.6.2015.
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