Contribution of genetic polymorphism of methylene tetrahydrofolate reductase on the effect of methotrexate in ectopic pregnancy patients

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.

Contribution of genetic polymorphism of methylene tetrahydrofolate reductase on the effect of methotrexate in ectopic pregnancy patients

Background

Methotrexate (MTX) is the prior drug in ectopic pregnancy (EP). However, approximately 10% of patients suffer from failure by MTX therapy. Reduced folate carrier 1 (RFC1), methylene tetrahydrofolate reductase (MTHFR), and dihydrofolate reductase (DHFR) are involved in the transport and effects of MTX in vivo. In the present study, we aim to investigate the relationship between the genetic polymorphisms of RFC1, MTHFR, and DHFR and the clinical efficacy of MTX in tubal pregnancies.

Methods

100 patients of EP were enrolled in this study. Polymorphisms of RFC1 G80A, MTHFR C677T, and DHFR A‐317G were genotyped. β‐hCG level was detected in day 0, 4, and 7 after MTX injection. Association of MTX efficacy and genetic polymorphisms was analyzed.

Results

Methylene tetrahydrofolate reductase C677T was associated with MTX treatment (P = .017). The success rate of first MTX injection was superior in patients with harboring mutation allele of MTHFR gene than that in patients with wild‐type gene (P = .001). However, there was no significant association between the polymorphisms of RFC1 G80A, DHFR A‐317G, and surgical treatment (P = .709 and .476, respectively). In addition, β‐hCG level decrement was not significantly changed by MTX injection with different polymorphisms of RFC1, MTHFR, and DHFR on either day 4 (P = .214, 0.197 and 0.270, respectively) or day 7 (P = .172, .554, and .726, respectively).

Conclusion

Our results suggested that the reliable indicator was polymorphism of MTHFR C677T in failure by MTX injection.