Myelosuppression Due to the Use of Azathioprine and COVID Infection and Severe Acute Colitis in a Patient With Ulcerative Colitis: Case Report

Female patient, 28 years old, diagnosed with ulcerative colitis 3 years ago, being treated with mesalazine 3.2g/day. She reports worsening of the condition with bloody mucous diarrhea, and azathioprine 150 mg/day was introduced without improvement. After 2 months, he presented Covid with the need for hospitalization in isolation. There was a worsening of the intestinal symptoms compatible with severe acute colitis and she was treated with hydrocortisone and later infliximab, as rescue therapy. The patient evolved with pancytopenia and fever, being treated as febrile neutropenic with the use of meropenem, fluconazole and vancomycin. Bone marrow puncture revealed myelosuppression probably due to the use of azathioprine and Covid infection. There was bone marrow recovery with suspension of azathioprine and use of filgrastim. After 2 weeks of hospitalization in an intensive care unit, the patient evolved with frank enterorrhagia and hemodynamic instability and a total colectomy with end ileostomy was performed in the emergency. Azathioprine is an immunomodulator generally used to maintain disease remission in steroid-dependent patients or for cases in which therapeutic doses of aminosalicytes have failed to control the disease. This class of drugs inhibits cell growth that is related to the inflammation process and the synthesis of nucleic acids. Thus, well-characterized adverse effects may occur, such as opportunistic infections, pancreatitis, hepatotoxicity, myelosuppression and malignancy. With regard to medullary toxicity, its occurrence is greater in the first 8 weeks of its use, occurring in 2 - 7% of patients with IBD treated with azathioprine. The present report draws attention to the myelosuppression that can occur as a serious side effect associated with the use of azathioprine. It is important to monitor patients who start using azathioprine with blood count and biochemical tests for the diagnosis of adverse events. The pharmacological management of ulcerative colitis should be based on the pillars of targeted therapy, on risk predictors, on the clinic presented by the patient, on laboratory and imaging tests. When there is a delay in deciding on top-down therapy, the outcome may be unfavorable, as in the case presented here. It highlights the rare presentation of myelosuppression by azathioprine and questions the role of COVID in the outcome of inflammatory disease and in the synergism of bone marrow inhibition.