In healthy individuals, plasma cells originating from the bone marrow produce immunoglobulin molecules composed of two heavy chains and two light chains. There are two types of light chains in humans. The κ light chains are encoded by the immunoglobulin κ locus on chromosome 2 and λ light chains are encoded by the immunoglobulin λ locus on chromosome 22 [1]. During B lymphocyte development, the...

An abnormal serum immunoglobulin free light chain (FLC) ratio at diagnosis may identify risk of progression to myeloma in patients with solitary bone plasmacytoma (SBP). In the cohort of 116 patients, 43 have progressed to myeloma, with a median time to progression of 1.8 years. The FLC ratio was determined in all 116 patients on serum collected at time of diagnosis and was abnormal in 54 patie...

RATIONALE In recent work, we have demonstrated a crucial role of mast cells in the development of viral myocarditis. Viral infection could lead to increased synthesis of free immunoglobulin light chains (FLC) and our earlier work showed that FLC can trigger mast cell activation. OBJECTIVE We studied the possible involvement of FLC in the pathogenesis of viral myocarditis, and therapeutic effe...

but the active/latent isoform proportions were similar (Fig. 1A). Platelet aggregation during clotting (6) may have caused these differences. MMP expression was lower in K 2 E plasma than in LH plasma [14 (3) vs 25 (4) ␮g/L; P Ͻ0.05; Fig. 1A, lane 4 vs lane 5]. The concentrations of MMP-9 forms decreased significantly with increasing amounts of K 2 E during PB collection, whereas MMP-2 was incr...

kIU/L; normal values 18 kIU/L) autoantibodies, and 2 were negative for all anti-phospholipid antibodies investigated by the ELISA method. Thus, the new SCT assay was positive in 87% of those who had a positive result by our LA test and was negative in 93% of those whose results were negative by our LA assay. All of these patients had histories of thromboembolic disease (4 with venous thrombosis...

Employment or Leadership: None declared. Consultant or Advisory Role: F.C. Wu, Organon International, Bayer Schering Pharma, Eli Lilly, Proctor & Gamble, Pierre Fabre Medicaments, Ferring Pharmaceuticals, TAP Pharmaceuticals, Ardana Bioscience, and GlaxoSmithKline. Stock Ownership: None declared. Honoraria: F.C. Wu, Organon International, Bayer Schering Pharma, Lilly ICOS, Ardana Bioscience, an...

The increased sensitivity of immunofixation electrophoresis (IFE) over prior electrophoretic methods has led to renewed interest in the study of free light chains. Here, we discuss problems associated with the identification of monoclonal free light chains (Bence Jones proteins) in urine. Besides reviewing the nature of the sample specimens and the assays themselves, we discuss the physiology, ...

The observation that only 50% of patients with adult asthma manifest atopy indicates that other inflammatory mechanisms are likely involved in producing the characteristic features of this disorder; namely reversible airway obstruction, hyperresponsiveness, and pulmonary inflammation. Our recent discovery that antigen-specific Ig free light chains (LCs) mediate hypersensitivity-like responses s...

subtraction, Marc H.M. Thelen, Jan van Bezu, Astrid Kok, and Ruud B.H. Schutgens ( Department of Clinical Chemistry, Vrije Universiteit Medical Centre, Amsterdam, Postbus 7057, 1007 MB Amsterdam, The Netherlands; 2 Clinical Laboratory, St-Annaziekenhuis, Postbus 90, 5660 AB Geldrop, The Netherlands; * address correspondence to this author at: Clinical Laboratory, StAnnaziekenhuis, Postbus 90, 5...

We present a case in which kappa free light chains caused difficulty in interpreting classical urinary immunoelectrophoresis, but immunofixation electrophoresis (IFE) demonstrated the presence of a lambda-Bence Jones protein. Analysis of the urine by Ouchterlony double diffusion and IFE after gel-filtration chromatography showed that the difficulty was caused by the presence of large amounts of...