Immune Adjuvant Therapy With Interleukin-7 in a Lymphopenic Patient With Aplastic Anemia and Mucormycosis

Abstract

Background: We report the case of a patient with aplastic anemia and pancytopenia on immune-suppressive therapy who developed invasive pulmonary infection with mucormycosis and was treated with immune adjuvant therapy.

Case summary: Given the patient's profound lymphopenia and progressive invasive mucor despite dual antifungal drug therapy, interleukin (IL)-7, a cytokine that induces lymphocyte activation and proliferation, was instituted and resulted in normalization of absolute lymphocyte counts and was temporally associated with clearance of fungal pathogens and resolution of clinical symptoms.

Conclusion: Patients with life-threatening fungal infections are frequently immune suppressed and immune adjuvant therapies should be considered in patients who are not responding to antifungal drugs and source control. Well-designed, double-blind, placebo-controlled trials are needed to advance the field. Although a number of immune adjuvants may be beneficial in fungal sepsis, IL-7 is a particularly attractive immune adjuvant because of its broad immunologic effects on key immunologic pathways that mediate enhanced antifungal immune system activity.

Keywords: fungal; immunity; infection; lymphocyte; sepsis.

Figure 1.

Top, Absolute lymphocyte counts over time: This timeframe of the absolute lymphocyte counts before, during, and after IL-7 administration shows a transient increase followed by an expected decrease in response to acute acalculous cholecystitis with bacteremia, after which the lymphocyte count continued to trend upward until returning to a near normal level approximately 60 d following injection. The peak value between days 48 and 56 likely reflects the impact of IL-7 given the absence of other associated factors, including administration of G-CSF, GM-CSF, and granulocyte infusions during that period. Bottom, Absolute granulocyte counts over time: This timeframe of the absolute granulocyte counts before, during, and after IL-7 therapy. Note the large increase in the absolute granulocyte count with the onset of cholecystitis and bacteremia. G-CSF = granulocyte-colony stimulating factor, GM-CSF = granulocyte macrophage colony-stimulating factor, IL = interleukin.