Multiple myeloma with monoclonal free IgG3 heavy chains and free kappa light chains.
We describe the case of a 34-year-old gentleman investigated for persistent neutropaenia following two episodes of pneumonia. Specialist investigations led to the diagnosis of multiple myeloma (MM) producing a truncated monoclonal gamma(3) heavy chain (HC) immunoglobulin molecule unattached to a light chain (LC) with atypical features for both MM and HC disease. Western blot showed gamma(3)HC was truncated with a large deletion (75 kDa). Flow cytometry of the bone marrow aspirate revealed an unusual staining pattern. This plasma cell dyscrasia was also unusual in that a subpopulation (30%) secreted large quantities of free LC (FLC) as well as truncated IgG HC. This is the first description, investigation and treatment of MM with a plasma cell population producing truncated gamma(3)HC and kappaFLC M-proteins and illustrates a number of unique immunological and clinical features.
Richter
Alex G
AG
Department of Immunology, Birmingham Heartlands Hospital, Birmingham, UK. alex.richter@heartofengland.nhs.uk
Harding
Stephen
S
Huissoon
Aarnoud
A
Drayson
Mark
M
Pratt
Guy
G
D000328:Adult; D006801:Humans; D007142:Immunoglobulin gamma-Chains / Q000097:blood* / Q000737:chemistry; D007145:Immunoglobulin kappa-Chains / Q000097:blood* / Q000737:chemistry; D008297:Male; D009101:Multiple Myeloma / Q000097:blood / Q000276:immunology* / Q000628:therapy; D036102:Peripheral Blood Stem Cell Transplantation; D016896:Treatment Outcome
D007142:Immunoglobulin gamma-Chains; D007145:Immunoglobulin kappa-Chains