title: Multiple myeloma with monoclonal free IgG3 heavy chains and free kappa light chains.
abstract: 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.
authors.affiliation: Department of Immunology, Birmingham Heartlands Hospital, Birmingham, UK. alex.richter@heartofengland.nhs.uk
authors.forename: Alex G
authors.initials: AG
authors.lastname: Richter
authors.forename: Stephen
authors.initials: S
authors.lastname: Harding
authors.forename: Aarnoud
authors.initials: A
authors.lastname: Huissoon
authors.forename: Mark
authors.initials: M
authors.lastname: Drayson
authors.forename: Guy
authors.initials: G
authors.lastname: Pratt
mesh_terms: 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
chemical_list: D007142:Immunoglobulin gamma-Chains; D007145:Immunoglobulin kappa-Chains