title: Thrombotic microangiopathy associated with monoclonal gammopathy.
abstract: Thrombotic microangiopathy (TMA) is a rare disease comprising of a diverse set of disorders linked by a common histologic finding of endothelial injury. Monoclonal immunoglobulins may act as a potential trigger in the pathogenesis of TMA. To determine the prevalence of monoclonal gammopathy and clinicopathological features of TMA associated with monoclonal immunoglobulin, we performed a retrospective study in adults (18 and older) with a clinical diagnosis of TMA. Of 146 patients with TMA, we detected monoclonal immunoglobulin in 20 patients (13.7%). Among patients 50 and older, the prevalence of monoclonal gammopathy was 21%, which is approximately five-fold higher than the 4.2% expected rate in this population. Fifteen patients had monoclonal gammopathy of undetermined significance, one had multiple myeloma, one with smoldering myeloma, two had POEMS syndrome, and one had T-cell lymphocytic leukemia. Renal biopsy was performed in 15 cases, of which six showed thrombi, 11 showed mesangiolysis, and all showed double contours along glomerular capillary walls. Acute tubular injury was present in 12 cases. Treatment options were varied and included therapeutic plasma exchange in 11 patients. Ten patients progressed to end-stage renal disease, of which two received kidney transplant. Thus, our study shows an unexpectedly high prevalence of monoclonal gammopathy in patients with TMA, suggesting a potential pathogenetic mechanism. This study underscores the importance of evaluating for a monoclonal gammopathy in patients with TMA as well as the potential for targeting the underlying hematologic disorder as an approach to treating TMA.
authors.affiliation: Division of Hematology, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Aishwarya
authors.initials: A
authors.lastname: Ravindran
authors.affiliation: Division of Hematology, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Ronald S
authors.initials: RS
authors.lastname: Go
authors.affiliation: Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Fernando C
authors.initials: FC
authors.lastname: Fervenza
authors.affiliation: Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA. Electronic address: Sethi.Sanjeev@mayo.edu.
authors.forename: Sanjeev
authors.initials: S
authors.lastname: Sethi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D001706:Biopsy; D018450:Disease Progression; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007668:Kidney / Q000473:pathology / Q000503:physiopathology; D007676:Kidney Failure, Chronic / Q000453:epidemiology / Q000601:surgery; D016030:Kidney Transplantation; D015458:Leukemia, T-Cell / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D008910:Minnesota / Q000453:epidemiology; D009101:Multiple Myeloma / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy; D016878:POEMS Syndrome / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy; D010265:Paraproteinemias / Q000175:diagnosis / Q000453:epidemiology* / Q000276:immunology / Q000628:therapy; D010951:Plasma Exchange; D015995:Prevalence; D006435:Renal Dialysis; D012189:Retrospective Studies; D012307:Risk Factors; D057049:Thrombotic Microangiopathies / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D007166:Immunosuppressive Agents
keywords: HUS; M protein; TTP; aHUS; kidney; monoclonal gammopathy; thrombotic microangiopathy