Apolipoprotein C-II Deposition Amyloidosis: A Potential Misdiagnosis as Light Chain Amyloidosis.

Hereditary amyloidoses are rare and pose a diagnostic challenge. We report a case of hereditary amyloidosis associated with apolipoprotein C-II deposition in a 61-year-old female presenting with renal failure and nephrotic syndrome misdiagnosed as light chain amyloidosis. Renal biopsy was consistent with amyloidosis on microscopy; however, immunofluorescence was inconclusive for the type of amyloid protein. Monoclonal gammopathy evaluation revealed kappa light chain. Bone marrow biopsy revealed minimal involvement with amyloidosis with kappa monotypic plasma cells on flow cytometry. She was started on chemotherapy for light chain amyloidosis. She was referred to the Mayo clinic where laser microdissection and liquid chromatography mass spectrometry detected high levels of apolipoprotein C-II, making a definitive diagnosis. Apolipoprotein C-II is a component of very low-density lipoprotein and aggregates in lipid-free conditions to form amyloid fibrils. The identification of apolipoprotein C-II as the cause of amyloidosis cannot be solely made with routine microscopy or immunofluorescence. Further evaluation of biopsy specimens with laser microdissection and mass spectrometry and DNA sequencing of exons should be done routinely in patients with amyloidoses for definitive diagnosis. Our case highlights the importance of determining the subtype of amyloidosis that is critical for avoiding unnecessary therapy such as chemotherapy

Case Report Levamisole/Cocaine Induced Systemic Vasculitis and Immune Complex Glomerulonephritis

Levamisole is an antihelminthic and immunomodulator medication that was banned by the USFDA in 1998. It has been increasingly used to adulterate cocaine due to its psychotropic effects and morphological properties. Adverse reactions including cutaneous vasculitis, thrombocytopenia, and agranulocytosis have been well described. Despite systemic vasculitis in this setting, renal involvement is uncommon. We report here a case of ANCA positive systemic vasculitis with biopsy proven immune complex mediated glomerulonephritis likely secondary to levamisole/cocaine. A 40-year-old Caucasian male with no past medical history presented with 3-week history of fatigue, skin rash, joint pains, painful oral lesions, oliguria, hematuria, worsening dyspnea on exertion, and progressive lower extremity edema. He had a history of regular tobacco and cocaine use. Lab testing revealed severe anemia, marked azotemia, deranged electrolytes, and 4.7 gm proteinuria. Rheumatologic testing revealed hypocomplementemia, borderline ANA, myeloperoxidase antibody, and positive atypical p-ANCA. Infectious and other autoimmune workup was negative. Kidney biopsy was consistent with immune mediated glomerulonephritis and showed mesangial proliferation and immune complex deposition consisting of IgG, IgM, and complement. High dose corticosteroids and discontinuing cocaine use resulted in marked improvement in rash, mucocutaneous lesions, and arthritis. There was no renal recovery and he remained hemodialysis dependent

Atypical Aortoesophageal Fistula with Atypical and Delayed Presentation and Negative Imaging Studies

A 59-year-old man with past medical history of thoracic aortic aneurysm treated with thoracic endovascular aortic repair presented with melena for 2 weeks. Initial EGD did not reveal the source of bleeding and showed normal esophagus; abdominal arteriogram did not reveal a fistulous communication and initial CTA showed normal position of the aortic graft stent without endoleak. The sixth EGD revealed a submucosal tumor-like projection in the upper esophagus and stigmata of recent bleeding. Another thoracic endovascular aortic repair with stent was placed over the old graft for presumed aortoesophageal fistula. Poststent upper gastrointestinal series with contrast showed extravasation of the contrast from the esophagus and CTA showed fistulous tract between aorta and esophagus. The patient refused definitive surgical repair despite having infected aortic graft; jejunostomy tube was placed and life-long suppressive antibiotic treatment was given and the patient is doing well at 2-year follow-up