WCN25-3318 MULTIPLE MYELOMA WITH RAPIDLY PROGRESSIVE RENAL FAILURE: DIAGNOSTIC CHALLENGE

endometrial cancers 4,5,9 .In patients with endometrial cancer, diagnosis of THSD7A-positive MN was preceded by cancer diagnosis.Thrombospondin was expressed in tumor cells leading to anti-THSD7A antibody formation and podocyte cytoskeleton disruption.Another cohort analysis showed a 20% prevalence of malignancy in THSD7A+ MN and 8 of the patients developed malignancy within 3 months of diagnosis of MN4.On extensive evaluation of our patient, we did not find any underlying malignancy.Clinically also patient did not have any symptoms pointing towards malignancy.Our patient was a young female in her early 20s as compared to a study where most patients were males with a mean age of 62 years 10.There was a case report of thrombospondin MN associated with eosinophilia 11.Our patient had no prior history of allergic disease and her absolute eosinophilic counts were normal.On further workup, her anti-SSAantibody was positive and a minor salivary gland biopsy revealed lymphocytic infiltration furthersupportingthe diagnosis of Sjogren syndrome.MN is the most common glomerulonephritis in Sjogren syndrome12.There is a case report of anti-PLA2R positivity in MN in primary Sjogren Syndrome13.In the literature review, we did not find an association of thrombospondin-positive MN with primary Sjogren syndrome.It is not SLErelated MN as anti-ds-DNA was negative and IF on biopsy did not have a full house pattern (negative for c1q, C3, IgM).Primary MN is generally associated with the IgG4 subclass of immunoglobulin deposit while secondary is with IgG1 though one study has shown that there might be class switching of antibodies and they found in their cohort that early-stage (stage1) had IgG1 dominant while late stages has IgG4 dominant 14.Interestingly in our patient, both IgG1 and IgG4 were dominant with 3+ staining, so whether it's primary THSD7A+ MN with coexisting Sjogren syndrome or Immune dysregulation due to Sjogren syndrome causing antibody against THSD7A and secondary MN is unclear. Conclusions:Conclusion: In summary, we report Thrombospondin positive MN in a young female with primary Sjogren syndrome without underlying malignancy.There are prior reports of PLA2R-positive MN with Sjogren syndrome, but to our best knowledge, this is the first case of THSD7A-positive MN in primary Sjogren syndrome.As with NELL-1, initially, it was thought to be commonly associated with underlying malignancy but later it was associated with many secondary causes of MN.We feel this might open the door to a new spectrum of diseases associated with thrombospondin-positive MN.