[IgA vasculitis with necrosis of the small intestine secondary to monoclonal gammopathy of renal significance: A case report].

Monoclonal gammopathy of undetermined significance combined with renal damage is named monoclonal gammopathy of renal significance. There are few reports about IgA vasculitis in patients with monoclonal gammopathy of undetermined significance. Here, we report a case of monoclonal gammopathy of renal significance, who had manifestations of IgA vasculitis, including purpura, gastrointestinal bleeding and joint pain. The patient had elevated serum creatinine levels, prompting further investigation through immunofixation electrophoresis and bone marrow aspiration biopsy. Immunofixation electrophoresis showed IgA-λ-type monoclonal immunoglobulin, while the bone marrow aspiration biopsy suggested plasmacytosis. Kidney biopsy indicated membranous hyperplastic glomerulonephritis, light and heavy chain deposition, IgA-λ. The patient was diagnosed with monoclonal gammopathy of renal significance. In light of the elevated serum creatinine, the patient was treated with chemotherapy regimen (bortezomib +cyclophosphamide +dexamethasone). After chemotherapy, there was no significant improvement in the patient's renal function. Subsequently, the patient experienced abdominal pain, skin purpura, joint pain and severe gastrointestinal bleeding. Gastroenteroscopy did not find the exact bleeding position. Angiography revealed hyperplasia of left jejunal artery. Surgical operation found that the bleeding site was located between the jejunum and ileum, where scattered hemorrhagic spots and multiple ulcers were present on the surface of the small intestine, with the deepest ulcers reaching the serosal layer. And the damaged intestine was removed during the operation. Intestinal pathology showed multiple intestinal submucosal arteritis, rusulting in intestinal wall necrosis and multiple ulcers. Considering intestinal lesions as gastrointestinal involvement of IgA vasculitis, methylprednisolone was used continually after the operation, and the patient's condition was improved. However, after half a year, the patient suffered a severe respiratory infection and experienced a recurrence of serious gastrointestinal bleeding. It was considered that the infection triggered the activity of IgA vasculitis, accompanied by gastrointestinal involvement. Finally, the patient died from gastrointestinal bleeding. The present case represented a patient with monoclonal gammopathy of renal significance and IgA vasculitis, prominently presenting with renal insufficiency and severe gastrointestinal bleeding, making the diagnosis and treatment process complex. Patients with IgA monoclonal gammopathy who presented with abdominal pain, purpura, and arthralgia should be vigilant for the possibility of concomitant IgA vasculitis. The treatment of cases with IgA vasculitis combined with monoclonal gammopathy of renal significance was rather challenging. Plasma cell targeting therapy might be an effective regimen for IgA vasculitis with monoclonal gammopathy. However, patients with poor renal response to the treatment indicated poor prognosis.