THU0604 UNDIAGNOSED RHEUMATIC DISEASE IN NEWLY PRESENTING MGUS PATIENT
Authors: Q. Zhou, K. Wang, L. Rahman, A. Watad, S. Savic, E. Roman, D. Mcgonagle
Journal: Annals of the Rheumatic Diseases (2020)

Background: Monoclonal gammopathy of undetermined significance (MGUS) is considered to be a premalignant condition with on average of 1% annual risk of progression to multiple myeloma or other lymphoproliferative disorders [1]. Numerous studies have highlighted a common feature of autoimmune inflammatory diseases is non-specific hypergammaglobulinaemia which can be associated with monoclonal gammopathy [2, 3]. We looked at a population of 3.6 million where patients with MGUS was referred to haematology network for evaluation. Objectives: Our hypothesis was that undiagnosed rheumatic diseases were being referred to haematology rather than rheumatology erroneously. Methods: The Haematological Malignancy Research Network (HMRN) ethics approval (REC 04/01/1205/69) from Leeds West Research Ethics Committee. The HMRN that comprises a population-based cohort of patients newly diagnosed by a single integrated haemato-pathology laboratory in two adjacent UK Cancer Networks (population 3.6 million). The database includes prognostic factors, sequential treatment/response history and socio-demographic details which are recorded to clinical trial standards. 255 patients were screened in this study. We looked at a range of autoimmune/innate immune conditions diagnosed after MGUS. Results: In the 255 patients cohort group, the average age at the diagnosis of MGUS was 70.23 ± 11.95 years (median 70.2 years), with more subjects being male (n=145, 56.9%). Mean duration of follow up was 2570 days. 10 out of the 255 patients progressed onto multiple myeloma. Diagnosed rheumatic disease was found in 48 patients (18.8%). None of the patient in this group has disease progression to multiple myeloma. In this group, 37 patients (14.5%) presented the rheumatic disease before their MGUS diagnosis and 11 (4.3%) were diagnosed after their MGUS referral. Interestingly, among the 11, more males(n=8, 72.7%) have their rheumatic disease diagnosed after MGUS. Those 11 cases included crohn’s disease (1), polymyalgia rheumatica (2), immune thrombocytopenia (2), autoimmune hepatitis (2), Schnitzler’s syndrome (1), giant cell arteritis (1), rheumatoid arthritis (2). Conclusion: Approaching 1 in 20 cases of MGUS have an underlying inflammatory disease that may often be non-specifically driving antibody production including monoclonal band formation. When diagnosing MGUS, clinicians should be aware of the potential underlying autoimmune rheumatic conditions. References: [1]Kyle, R.A., et al., A long-term study of prognosis in monoclonal gammopathy of undetermined significance. N Engl J Med, 2002. 346 (8): p. 564-9. [2]Renier, G., et al., Ankylosing spondylitis and monoclonal gammopathies. Ann Rheum Dis, 1992. 51 (8): p. 951-4. [3]Sugai, S., et al., Non-IgM monoclonal gammopathy in patients with Sjogren's syndrome. Am J Med, 1980. 68 (6): p. 861-6. Disclosure of Interests: Qiao Zhou: None declared, Kaiwen Wang: None declared, Laiba Rahman: None declared, Abdulla Watad: None declared, Sinisa Savic: None declared, Eve Roman: None declared, Dennis McGonagle Grant/research support from: Janssen Research &amp; Development, LLC