Introduction:
Sjogren’s syndrome (SjS) is a systemic autoimmune disease characterized by infiltration of lymphocytes in exocrine glands, primarily the lacrimal and salivary ones. A subset of patients with SjS will also have extraglandular manifestations. The most common kidney disease in SjS is tubulointerstitial nephritis, with patients often presenting with electrolyte derangements secondary to renal tubular acidosis or nephrogenic diabetes insipidus. Less commonly, glomerular involvement in patients with SjS will present with acute kidney injury (AKI) and nephrotic syndrome.
Methods:
A 78 year old male presents to the emergency department for ankle swelling over the past week, with associated frothy urine. Patient’s history is significant for SjS on hydroxychloroquine and benign prostate hyperplasia status post transurethral resection of the prostate many years ago, complicated by incomplete emptying, requiring self catheterization twice a day. On physical exam, patient was found to have bilateral pedal edema and a chronic petechial rash on bilateral shins. Labs were notable for creatinine 2 mg/dL (baseline 1.6 mg/dL), albumin 2.7 g/dL, ESR 25 mm/hr (previously 15 mm/hr), CRP 1.1 mg/dL (stable from prior mg/dL), C3 47 mg/dL, and C4 <3mg/dL, LDL 87 mg/dL. Urine protein:creatinine 4.64 mg/dL (previously 1.87 mg/dL). Post void residual bladder scan was 500cc. Patient was admitted for nonoliguric AKI. Nephrology was consulted. AKI was thought secondary to urinary retention because of improvement of creatinine after foley placement. Patient was discharged with instruction to increase frequency of self-catheterization and to follow up with nephrology outpatient regarding glomerulonephritis workup for worsening proteinuria. Within one week, patient was readmitted for AKI again with worsening lower extremity edema. Creatinine on readmission was 3.2 mg/dL, eGFR 19 L. Serology from prior admission showed cryoglobulin positive with cryocrit 3%; ANA 1:1280 with positive SSA/SSB, kappa/lambda light chain ratio 7.15, PLA2R antibody negative, viral hepatitis panel non-reactive. Nephrology, rheumatology, and hematology were consulted. Renal biopsy confirmed cryoglobulinemic glomerulonephritis with focal crescents and extraglomerular necrotizing vasculitis as well as tubulointerstitial nephritis with prominent eosinophils. Bone marrow biopsy and CT chest, abdomen, pelvis (CT CAP) were also performed to rule out cryoglobulinemia secondary to a lymphoproliferative disorder. Bone marrow pathology revealed no morphologic diagnostic evidence of involvement by a plasma cell neoplasm. CT CAP revealed no lymphadenopathy or lytic lesions. Patient was diagnosed with mixed cryoglobulinemia secondary to SjS. He was started on Solumedrol 1g daily for three days and discharged on oral Prednisone.
Results:
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Conclusions:
Cryoglobulins are immunoglobulins that precipitate at cold temperatures and can induce cutaneous vasculitis and kidney damage as seen in our patient. While hepatitis C infection is typically associated with mixed cryoglobulinemia, autoimmune diseases, including SjS are typically associated with non-hepatitis C related mixed cryoglobulinemia. Therefore, in patients with SjS, it is essential to check cryoglobulins in the setting of rapidly worsening renal function and an unexplained AKI.
I have no potential conflict of interest to disclose.
I did not use generative AI and AI-assisted technologies in the writing process.