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The serum heavy/light chain immunoassay: A valuable tool for sensitive paraprotein assessment, risk, and disease monitoring in monoclonal gammopathies
Author(s) -
Greil Christine,
Ihorst Gabriele,
Gaiser Felix,
Salzer Ulrich,
Bisse Emanuel,
Kastritis Efstathios,
Ludwig Heinz,
Wäsch Ralph,
Engelhardt Monika
Publication year - 2017
Publication title -
european journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.904
H-Index - 84
eISSN - 1600-0609
pISSN - 0902-4441
DOI - 10.1111/ejh.12958
Subject(s) - serum protein electrophoresis , medicine , monoclonal gammopathy of undetermined significance , immunoassay , multiple myeloma , immunofixation , monoclonal , immunoglobulin light chain , gastroenterology , al amyloidosis , plasma cell dyscrasia , macroglobulinemia , antibody , immunology , pathology , monoclonal antibody
Objective The heavy/light chain ( HLC )‐immunoassay quantifies light chain types of each immunoglobulin class in patients with monoclonal gammopathies. Methods We assessed 147 consecutive patients with different forms and stages of plasma cell dyscrasias ( PCD ) who received standard tests (serum and urine protein electrophoresis [ SPEP , UPEP ], immunofixation [ IFE ], serum‐free light chain [ SFLC ]), and HLC ‐immunoassay. Patients with multiple myeloma ( MM , n = 102), smoldering MM ( SMM , n = 5), monoclonal gammopathy of undetermined significance ( MGUS , n = 28), and Waldenström's macroglobulinemia ( WM , n = 12) were included. Results We verified a significant correlation between HLC ‐ and standard monoclonal protein (mp)‐parameters, and HLC ‐increases with higher disease stage and unfavorable remission status. In patients with difficult to quantify mp, more abnormal HLC ‐ than SPEP ‐, immunoglobulin‐, or SFLC ‐results were found. In WM , a pathological HLC κ/λ‐ratio and M‐component were observed in 95% and 58%, respectively. In 21/28 MGUS and 5/5 SMM patients, HLC κ/λ‐ratios were abnormal. Testing different HLC cutoffs, patients with extreme HLC values showed impaired progression‐free survival ( PFS ). Conclusions Despite the fact that different PCD patients were included, the assessment of the HLC ‐immunoassay in MGUS , SMM , MM , and WM , our comparison with standard mp‐assays, and relevant PFS differences may excite future applications, which should be confirmed in prospective multicenter trials.