{
  "abstract": "Objectives Be aware of lupus Nephritis (LN) mimics, including Cryoglobulinemic Glomerulonephritis (GN), as it would change the treatment course and outcomeMethods This is a case of a 60 yo F with hx of SLE who presented with AKI (Cr 3.09), anasarca, HTN, hematuria & 1 gr proteinuria.SLE Dx was at the age of 27, based on +ANA with nucleolar pattern, inflammatory arthritis, photosensitivity, Coombs positive hemolytic anemia, supported by Raynaud’s, and +anti-SSA antibody. Since Dx, she had been treated with prednisone, hydroxychloroquine (HCQ) and mycophenolate mofetil (MMF). She was off her lupus meds at the time of admission.Her work-up showed normocytic anemia, low C3 of 67, low C4 of 4. It was negative for: anti-dsDNA, anti-Sm, RNA polymerase III Ab, SCl-70 Ab, ANCA, anti-phospholipid Abs, anti-GBM, hepatitis B/C/HIV and ADAMTS13 deficiency. There was no active hemolytic anemia. Renal biopsy was suggestive of TMA plus LN class IV. She was treated with pulse IV Solumedrol followed by prednisone taper, HCQ, MMF and later one, MMF was switched to azathioprine then tacrolimus with partial response. She continued to have low GFR, hematuria, proteinuria and very low C4. Given lack of good explanation for TMA and partial response to Tx, the renal biopsy slides were sent for re-read.Results Renal biopsy re-read was reported as type II cryoglobulinemic GN, not TMA/LN. The ‘thrombi’ described on biopsy represented pseudo-thrombi consistent with cryoglobulinemia rather than true TMA. Further work up showed cryo-crit of 7.7%, a monoclonal IgM and a polyclonal IgG, consistent with type II cryo. She had small IgM kappa/IgG lambda on serum immunofixation.Following this Dx, she was treated with 3 sessions of plasmphaphresis followed by rituximab with excellent clinical and lab response. GFR, C4, cryo and urine protein normalized, and she remained in remission 5 years later on rituximab monotherapy as maintenance therapy.Conclusions This is a case of cryo GN masquerading as proliferative LN+TMA.Careful clinicopathologic correlation and consideration of cryoGN in atypical or treatment-refractory ‘lupus nephritis’ may prevent misdiagnosis and optimize outcomes, as cryo GN responds better to PLEX and Rituximab Tx as reported in this case.",
  "authors": [
    {
      "affiliations": [
        "University of Minnesota, Minneapolis, USA"
      ],
      "name": "Parastoo Fazeli"
    }
  ],
  "title": "PO:04:113 Case report: lupus nephritis or a mimic?",
  "uid": "82a322b0-07fc-585d-bd7a-d726dc78774a"
}