Case of Methotrexate-Induced Pancytopenia and Ulcerations in Psoriasis Patient with CKD: A report

Methotrexate (MTX), a widely prescribed immunosuppressant and chemotherapeutic agent, is used to treat autoimmune diseases like psoriasis and rheumatoid arthritis, as well as certain malignancies. By inhibiting dihydrofolate reductase, MTX disrupts DNA synthesis and cell proliferation. Although it is generally effective, MTX has a narrow therapeutic index and can lead to severe adverse effects, including hepatotoxicity, pulmonary toxicity, and hematological issues such as pancytopenia. Pancytopenia, which involves a reduction in red blood cells, white blood cells, and platelets, poses significant health risks and requires prompt management.

The risk of methotrexate toxicity is particularly pronounced in patients with renal impairment. Since the kidneys are responsible for the primary excretion of MTX, impaired kidney function can lead to drug accumulation and increased toxicity. This heightened risk is compounded by the fact that early symptoms of MTX-induced pancytopenia—such as mucosal ulcers, fever, and general weakness—can be subtle, making early detection essential.

The recent case report details a male patient in his late 40s with a complex medical history, including psoriasis, insulin-dependent type 2 diabetes mellitus, chronic kidney disease stage 3b, and coronary artery disease (CAD). The patient presented to the emergency department with a one-week history of fever, weakness, and mouth sores, along with bilateral lower limb swelling and pain. Despite stable vital signs, a physical examination revealed pallor, large ulcerative lesions in the buccal mucosa, and erythematous, scaly lesions on his lower limbs.

The patient’s medication history included methotrexate, which he had stopped two months prior but inadvertently resumed at an increased dose two weeks before his emergency visit. Laboratory tests showed pancytopenia with worsening trends, leading to a bone marrow biopsy that revealed hypocellular marrow. Given the patient’s CKD, impaired clearance of MTX likely exacerbated the toxicity.

Treatment for the patient included intravenous leucovorin to counteract methotrexate toxicity, blood and platelet transfusions and granulocyte-macrophage colony-stimulating factor (GM-CSF). Following intensive care, the patient experienced significant recovery, with improvements in blood counts and resolution of symptoms. He was eventually discharged with stable hemoglobin, platelet, and white blood cell counts.

This case underscores the critical need for careful medication management in patients with CKD to prevent methotrexate toxicity and highlights the importance of monitoring for early signs of adverse effects in patients with complex medical conditions.

Reference:

Surapaneni D, Dasi S, Sam N, et al. (August 05, 2024) Methotrexate Toxicity-Induced Pancytopenia and Mucocutaneous Ulcerations in Psoriasis. Cureus 16(8): e66222. doi:10.7759/cureus.66222