SUN-440 RENAL DISEASE PRESENTATION IN MIXED CRYOGLOBULINEMIA TYPE 2 A CASE REPORT AND A LITERATURE REVIEW

Abstract

Mixed cryoglobulinemia (MC) results of cryoprecipitable immunocomplexes. In type II MC, a combination of polyclonal and monoclonal immunoglobulin is found. Renal involvement (RI) is one of the most serious complications in MC and may affect the overall prognosis. Case presentation: A diagnosis of essential mixed cryoglobulinemia (EMC) was established in a 36-year-old female patient. Eight years earlier, shedevelopedpurpuraof the lower extremities, arthralgia, peripheral neuropathy andpulmonary renal syndrome. A skin biopsy revealed a leukocytic vasculitis.A mixed cryoglobulin and hypocomplementemia were found. Urinary protein excretion was at 12 g per 24h. Initial treatment included pulse methylprednisolone followed by prednisone (1 mg/kg daily). Despite the clinical improvement in the renal disease, palpable purpuric lesions with arthralgia recurred periodically. So methotrexate was introduced but was rapidly interrupted owing to liver toxicity. On June 2019, she was admitted for pneumonia. An outbreak of her disease with dermal, peripheral nerve and renal involvement was objectified. Urinary protein excretion was at 3 g per 24h. A mixed cryoglobulin with monoclonal IgM Kappa and polyclonal immunoglobulin persisted. A Renal biopsy (RB) was done in July 2019, revealed diffuse endocapillary proliferation with granular IgM, C3 deposits. Plasmapheresis with twice exchanges per weak was conducted. Five days after the initiation of therapy, her purpura disappeared and serum complement values returned to normal. Review of the literature: The results of a long-term prospective, randomized controlled trial of rituximab (RTX) monotherapy in patients with cryoglobulinemia vasculitis (CV). RTX was found to be superior to standard immunosuppressive therapy for severe CV over the long term. A multicenter retrospective study included 14 patients with EMC who were successfully treated with lenalidomide. A study, included 21 patients with severe type II EMC unresponsive to immunosuppressive regimens, showed that IFN-a, as a single agent, is able to determine a response rate as high as 77%. A case report demonstrated that 2-Chlorodeoxyadenosine (2CdA) induced a dramatic and prolonged clinical response for a patient with progressive, symptomatic cryoglobulinemia, in whom corticosteroid and alkylating therapy failed. Some studies suggest that plasma exchange alone might be indicated in the treatment of a rapidly progressive glomerulonephritis complicating MC. We presented this case of EMC with renal involvement. The clinical presentation is characterized by a normal kidney function without nephrotic syndrome with membranoproliferative glomerulonephritis (MPGN) at the renal biopsy. This case reveals the importance of RB for the diagnosis of MPGN even in front of an atypical clinical picture.