[Incidence and type of monoclonal or biclonal gammopathies in scrub typhus].
BACKGROUND
Korea is an endemic area of scrub typhus and it is a common seasonal febrile illness. Although, various humoral immune responses to scrub typhus have been documented, no association between gammopathy and scrub typhus has ever been reported. We analyzed the incidences and types of monoclonal and biclonal gammopathies in scrub typhus for better coping with those gammopathies in scrub typhus.


METHODS
Anti-Orientia tsutsugamushi antibody-positive sera identified by indirect immunofluorescence assay were acquired from 40 patients with confirmed scrub typhus. Monoclonal and biclonal gammopathies were screened by protein electrophoresis and were confirmed using immunofixation electrophoresis (IFE). Laboratory findings on admission of the patients with monoclonal or biclonal gammopathy were investigated retrospectively to characterize the gammopathies.


RESULTS
Monoclonal or biclonal gammopathies were detected in 30% (12/40) of patients with scrub typhus (IgG-lambda, 40%; IgG-kappa, 30%; IgM-kappa, 10%; IgM-lambda, 10%; IgA-kappa, 5%; IgA-lambda, 5%). Concentrations of clonal immunoglobulin were less than 3 g/dL in all gammopathies, and hypercalcemia was not detected in any of the patients.


CONCLUSIONS
Our results suggest possible association between gammopathies and scrub typhus. Further studies in larger series will be needed for exact incidence and clinical course of gammopathies in scrub typhus.
Department of Laboratory Medicine, School of Medicine, Wonkwang University, Iksan, Korea.
Ji Hyun
JH
Cho
Do Sim
DS
Park
D000328:Adult; D000368:Aged; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007143:Immunoglobulin Heavy Chains / Q000097:blood; D007147:Immunoglobulin Light Chains / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D015994:Incidence; D008875:Middle Aged; D012285:Orientia tsutsugamushi / Q000276:immunology; D010265:Paraproteinemias / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology / Q000276:immunology; D012189:Retrospective Studies; D012612:Scrub Typhus / Q000150:complications / Q000175:diagnosis* / Q000276:immunology
D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007143:Immunoglobulin Heavy Chains; D007147:Immunoglobulin Light Chains; D007075:Immunoglobulin M