Low-dose methotrexate-induced renal failure in a patient with ectopic pregnancy: a case report

BACKGROUND: Methotrexate is an anticancer drug from the antimetabolite class. It is also used in gynecology and obstetrics for the medical treatment of ectopic pregnancies. Low-dose methotrexate-induced adverse toxic effects are rare. We report a case of toxic effect associated with severe renal insufficiency induced by LD-MTX (Low-Dose Methotrexate) for ectopic pregnancy. CASE PRESENTATION: A 46-year-old Chinese woman was in an operation for an ectopic pregnancy of tubal interstitial pregnancy. The embryo villus was so little that we were not sure if it was evacuated, then it was followed with 50 mg methotrexate injection of intramuscular adjacent the uterine horn in the operation. 48 hour later after injection the patient presented with renal failure. The personalized genetic testing showed that MTHFR (677C > T) and ABCB1 (3435T > C) were detected. Gradually, the symptoms improved after calcium leucovorin (CF) rescue, continuous renal replacement therapy (CRRT), promoting blood system regeneration, and multiple supportive treatments. CONCLUSIONS: When toxic effects are suspected, detecting the polymorphisms of an MTHFR gene and monitoring MTX concentration in blood could assist us to formulate individualized and active treatments. The management should be multidisciplinary and as much as possible within an intensive care unit.