Abstract Introduction Hyperleukocytosis due to acute myeloid leukemia (AML) can lead to severe complications including increased blood viscosity and impaired organ perfusion. However, hyperleukocytosis associated with viscosity leading to respiratory failure is relatively rare (1). In this case, the AML-induced leukocytosis resulted in life-threatening respiratory failure, requiring urgent leukapheresis and intensive supportive care. Case Presentation An 81-year-old male with a history of prostate cancer post-prostatectomy and advanced myelodysplastic syndrome (MDS) diagnosed nine years back presented with worsening dyspnea. He had undergone reduced-intensity conditioning unrelated to donor peripheral blood stem cell transplant (RIC URD PBSCT) eight years back and had been in remission since being maintained on tacrolimus for chronic graft-versus-host disease (GVHD). The patient initially sought evaluation for exertional dyspnea and was suspected of having pulmonary GVHD. He was admitted to a local hospital with worsening shortness of breath and diagnosed with bilateral pneumonia and COVID-19. His condition deteriorated with increasing leukocytosis (WBC 105k, peripheral blasts 85%), prompting transfer to a higher-level care facility for evaluation of relapsed AML. Upon arrival, he was on a heated high-flow nasal cannula (HHFNC) and required intensive care unit (ICU) level care following a hypoxic event. The management included cytarabine and hydroxyurea for leukoreduction, leukapheresis, and antimicrobial therapy. The patient developed acute hypoxic respiratory failure complicated by pulmonary hemorrhage, necessitating intubation, and tranexamic acid nebulization. Despite aggressive interventions, his condition deteriorated, with recurrent respiratory failure, septic shock requiring vasopressors, and multi-organ dysfunction. After multiple complications, including pulmonary hemorrhage, coagulopathy, and worsening shock, unfortunately, the patient succumbed to his illness. Discussion Hyperleukocytosis, commonly defined as a white blood cell (WBC) count exceeding 100,000/µL, is a common complication of AML that can result in leukostasis, a life-threatening emergency. Leukostasis occurs because of increased viscosity and reduced deformability of leukemic blasts, leading to impaired microvascular perfusion and subsequent organ dysfunction (1). The respiratory system is one of the most affected organs, with pulmonary leukostasis manifesting as dyspnea, hypoxemia, and diffuse alveolar hemorrhage. Although leukostasis is more commonly associated with acute leukemia, its role in AML-induced respiratory failure remainsunclear. Diagnosis is often challenging, as respiratory distress in AML patients can also be attributed to infections, leukemic infiltration, or treatment-related complications (2). Conclusion Hyperleukocytosis due to acute myeloid leukemia can result in leukostasis and life-threatening respiratory failure requiring urgent intervention. Early recognition and prompt management with leukapheresis and cytoreductive therapy are essential to improve patient outcomes. This abstract is funded by: None
Regmi et al. (Fri,) studied this question.