Myeloid reconstitution syndrome is a condition observed during the recovery phase of the immune system, particularly in patients recovering from neutropenia after treatments like chemotherapy or stem cell transplantation. This syndrome can be likened to immune reconstitution inflammatory syndrome (IRIS) in its broader context, where the immune system’s recovery leads to an inflammatory response to previously latent or controlled infections.

• Definition and Context: Myeloid reconstitution syndrome involves the inflammatory response that occurs when neutrophils, a type of white blood cell, recover from low counts (neutropenia) post-treatment. This can lead to symptoms like fever, rash, pulmonary infiltrates, and capillary leak, which are signs of the body’s immune system reacting to pathogens that were not effectively combated during the period of immunosuppression.
• Clinical Presentation: Patients might experience a paradoxical worsening of symptoms or the unmasking of occult infections as their immune system regains function. This is often seen in the context of hematologic malignancies or after stem cell transplants where the immune system, particularly the myeloid lineage, begins to recover.
• Associated Conditions and Pathogens: Conditions like acute myeloid leukemia (AML), myelodysplastic syndromes (MDS), or infections from pulmonary pathogens can be associated with this syndrome. The recovery of neutrophils can lead to an aggressive immune response against fungi like Aspergillus or bacteria like Mycobacterium tuberculosis, leading to clinical manifestations of IRIS.
• Management: Treatment often involves supportive care, management of symptoms, and sometimes the use of corticosteroids to control inflammation, particularly if the symptoms are life-threatening or severe. The underlying infection or condition also needs to be treated appropriately.
• Prognosis and Research: Understanding the mechanisms behind myeloid reconstitution syndrome is crucial for better management and outcomes in affected patients. Research continues to identify molecular targets and biomarkers that could predict or mitigate the severity of this syndrome.

This syndrome highlights the complex interaction between the recovering immune system and persistent infections or residual disease, emphasizing the need for careful monitoring during the recovery phase of immunosuppressive treatments.

Disclaimer: not medical advice. please consult a medical professional.