The patient underwent a kidney biopsy in November 2017 that revealed HSP nephritis (HSPN, ISKD classified as type III, defined as focal hyperplasia and sclerosis), with isolated positive [kappa]-light chain and negative lambda light chain
immunostaining (Figure 1).
Urine protein electrophoresis demonstrated elevated free lambda light chain
, and bone-marrow biopsy demonstrated elevated levels of clonal plasma cells, consistent with diagnosis of multiple myeloma with associated amyloidosis.
Flow cytometry of the dialysate showed predominately monotypic B cells with lambda light chain
restriction that coexpressed CD20 and CD19 but lacked CD5 and CD10 suggestive of a monoclonal lymphoid process.
There was no elevation of free kappa and lambda light chain
in serum or urine, also with the normal light chain ratio (Table 1).
While it was already presumed that the M[alpha]F-IgL mAb were targeting the constant region of kappa or lambda light chain
based on their FCM staining patterns (Figure 6), it remained unclear if these anti-kappa or anti-lambda mAb were targeting distinct or overlapping epitopes.
Immunohistochemical panel included CD3, CD20, and CD138 immunohistochemical stains as well as kappa and lambda light chain
in situ hybridization.
Furthermore, plasmablasts in MCD are CD20+ and EBV negative and show exclusively lambda light chain
The company's new resin, LambdaFabSelect, is a designed tool for the GMP-regulated purification of antibodies and antibody fragments that contain a lambda light chain
. Antibody fragments are currently said to be receiving increased attention as potential future biopharmaceuticals because, when compared with monoclonal antibodies, they have a number of advantages including improved tissue penetration and the ability to bind to targets inaccessible to conventional antigen-binding sites.
Serum IgG was 3.98 g/dI (7-16), IgA 9.7 g/dI (0.7-4), IgM 0.43 g/dl (0.4-2.3), lambda light chain
3.94 g/L (0.9-2.1), and kappa light chain 1.25 g/L (1.7-3.78).
Sensitive probes include: Epstein-Barr encoded RNA (EBER), kappa light chain, lambda light chain
, dual kappa/lambda, IgA-alpha heavy chain, IgG-gamma heavy chain, IgM-mu heavy chain, and ribosomal RNA (positive control).
These cells express IgM and show lambda light chain