2018 Volume 27 Issue 11 Pages 847-851
A 68-year-old male with primary central nervous system lymphoma in the deep brain was intravenously administered with a high dose of methotrexate (MTX) as the initial treatment. The patient developed fever a few hours after MTX administration. His laboratory tests revealed elevation of serum creatinine and C-reactive protein levels, suggesting acute kidney injury caused by MTX or some kind of infection. However, systemic computed tomography and various culture tests did not show any focus of infection. Gallium scintigraphy demonstrated uptake in the bilateral kidneys and eosinophiluria was found. Drug-induced lymphocyte stimulation test revealed a positive reaction to MTX. These examinations suggested that the acute kidney injury and inflammatory response resulted from acute interstitial nephritis (AIN) caused by allergic reaction to MTX. Although the serum creatinine level spontaneously improved, we avoided a second course of MTX to prevent AIN recurrence. The patient underwent whole-brain radiation therapy and achieved complete response. His follow-up MRI did not reveal any tumor recurrence for 7 months. To the best of our knowledge, AIN has not been reported in relation to MTX administration in the literature. Although this was a rare cause of acute kidney injury by MTX, the recognition of such a mechanism is important because AIN can occur even independent of MTX administration, which can deem MTX re-administration fatal.
