Immune biomarkers and secondary hemophagocytic lymphohistiocytosis: a scoping review protocol.

Objective: To identify immunological pathways and markers of severity of illness associated with clinical outcomes that may represent potential therapeutic targets in the management of secondary hemophagocytic lymphohistiocytosis.

Introduction: A broad range of immunomodulatory therapies is used to manage hemophagocytic lymphohistiocytosis, however the supporting evidence for these therapies is scarce. Identifying patients likely to experience more severe disease, or die, is currently extremely difficult, if not impossible. The identification of implicated cytokines in secondary disease can provide further support for the identification of high-risk patients and the development of targeted therapies.

Inclusion criteria: Studies reporting immune biomarker and cytokine measurement in adult patients (age >18 years) with secondary hemophagocytic lymphohistiocytosis.

Methods: The proposed review will be conducted in line with the JBI methodology for scoping reviews. The MEDLINE (Ovid) and Embase (Ovid) databases will be searched, without date limitations. Data will be extracted using a data extraction tool developed by the reviewers. Relevant sources will be retrieved, and their citation details imported into the JBI System for the Unified Management, Assessment and Review of Information.