Azathioprine teratogenicity: review of the literature and case report

Area of Science:

• Pharmacology
• Teratology
• Developmental Biology
• Orthopedics

Background:

• Azathioprine (AZA) is an immunosuppressive drug used in various autoimmune conditions.
• Its metabolite, 6-mercaptopurine (6-MP), also possesses immunosuppressive and potential teratogenic properties.
• Pregnancy exposure to AZA and 6-MP necessitates careful evaluation due to potential developmental risks.

Observation:

• A case report details an infant diagnosed with preaxial polydactyly.
• The infant's mother received azathioprine treatment throughout her gestation period.
• Preaxial polydactyly involves an extra digit on the thumb or big toe side of the hand or foot.

Findings:

• Experimental animal studies indicate that azathioprine and 6-mercaptopurine exhibit teratogenic effects.
• The skeletal system is identified as a primary target tissue for the teratogenic actions of these drugs.
• The observed infant anomaly shares similarities with experimentally induced azathioprine teratogenesis in animal models.

Implications:

• While a direct causal link cannot be definitively established from this single case, the findings raise concerns.
• The potential for azathioprine-induced skeletal malformations in human infants requires further clinical surveillance.
• This case highlights the importance of monitoring pregnancies in mothers undergoing immunosuppressive therapy.