Antitubular Basement Membrane Antibody Disease Associated with Nivolumab Infusion and Concomitant Acute Pyelonephritis Leading to Acute Kidney Injury : a Case Report and Literature Review.

Antitubular basement membrane (anti-TBM) antibody disease is an extremely rare disorder. It may be idiopathic or secondary to exposure of the proximal tubular basement membrane, triggered by tubular injury due to acute pyelonephritis, acute allergic interstitial nephritis, or kidney allograft rejection. The histopathology of anti-TBM antibody disease is characterized by strong linear deposits of IgG with complement C3 along the proximal tubular cell basement membranes. The staining is restricted to proximal tubules. Currently, a kidney biopsy with these pathognomonic findings is the only diagnostic method. Serological testing and titers for anti-TBM antibodies are not clinically standardized. Our patient had pyelonephritis and possibly acute allergic interstitial nephritis as a result of nivolumab infusion. The kidney biopsy demonstrated dense interstitial infiltrates of neutrophil-rich interstitial inflammation, neutrophilic casts, and neutrophilic tubulitis consistent with acute pyelonephritis, as well as areas of mixed inflammation with lymphocytic tubulitis suggesting concurrent acute interstitial nephritis. The presence of linear IgG staining along proximal but not distal tubular basement membranes was diagnostic of anti-TBM antibody disease, favored to be due to both triggers. The patient was treated with discontinuation of nivolumab, intravenous antibiotics, and corticosteroids and was supported with hemodialysis. After 6 weeks, the patient's kidney function recovered enough to discontinue hemodialysis and had significant renal improvement.

Probable Clostridium septicum pneumocephalus in a user of natural remedies with newly diagnosed diabetes mellitus type 1.

Clostridium septicum encephalitis is a rare cause of spontaneous, non-traumatic pneumocephalus. Systemic infections with this organism have a fulminant course, likely leading to death within 48 hours, and are commonly associated with hematological or colonic malignancies. The effectiveness of an antibacterial regimen is unknown because of a lack of studies. The best prognosis is observed in patients undergoing early surgical intervention for localized intracranial processes. Here we describe a case of rapidly developing C. septicum sepsis as a result of bacteremia and hematogenous spread, resulting in encephalitis and pneumocephalus in a patient without a diagnosed malignancy. The patient presented to the emergency department with diabetic ketoacidosis, which led to the diagnosis of new-onset type 1 diabetes mellitus. There are currently 19 reported cases of C. septicum central nervous system infections in the literature, with 12 of them having pneumocephalus. Natural remedies, such as drinking kombucha tea and performing coffee enemas, that were used by our patient may have played a role in the dissemination of C. septicum. In survivors of this fulminant illness, colonic and hematologic malignancies should be excluded because of their association with such infections. Type 1 diabetes mellitus, drinking kombucha tea, and performing coffee enemas may be newly recognized risk factors associated with the dissemination of C. septicum.