Invasive fungal infection in an elderly patient with defective inflammatory macrophage function

Sphingolipids as Regulators of the Phagocytic Response to Fungal Infections

Fungal infections pose a significant risk for the increasing population of individuals who are immunocompromised. Phagocytes play an important role in immune defense against fungal pathogens, but the interactions between host and fungi are still not well understood. Sphingolipids have been shown to play an important role in many cell functions, including the function of phagocytes. In this review, we discuss major findings that relate to the importance of sphingolipids in macrophage and neutrophil function and the role of macrophages and neutrophils in the most common types of fungal infections, as well as studies that have linked these three concepts to show the importance of sphingolipid signaling in immune response to fungal infections.

Effect of Granulocyte-Macrophage Colony-Stimulating Factor on Prevention and Treatment of Invasive Fungal Disease in Recipients of Allogeneic Stem-Cell Transplantation: A Prospective Multicenter Randomized Phase IV Trial

PURPOSE

For recipients of allogeneic hematopoietic stem-cell transplantation (alloHSCT), we hypothesized that prophylactic therapy during neutropenia with granulocyte-macrophage colony-stimulating factor (GM-CSF) decreases invasive fungal disease (IFD).

PATIENTS AND METHODS

We randomly assigned 206 patients undergoing alloHSCT to receive once-daily subcutaneous GM-CSF (5 to 7 μg/kg per day), granulocyte colony-stimulating factor (G-CSF; 5 to 7 μg/kg per day), or a combination of G-CSF and GM-CSF (2 to 3 μg/kg per day each). Treatment was started on day 5 after transplantation and was continued until the absolute neutrophil count was ≥ 1.5 × 10(9)/L for 2 consecutive days. The primary outcomes were 100-day incidence of proven and probable IFD and response rate of antifungal treatment.

RESULTS

For the intent-to-treat population, there was no significant difference in 100-day incidences of proven and probable IFD among the three groups. The antifungal treatment response was better in the GM-CSF group and G-CSF+GM-CSF group than in G-CSF group from day 22 to day 100 (P = .009). The 100-day cumulative mortality after transplantation was lower in the GM-CSF group than in the G-CSF group (10.3% v 24.6%, respectively; P = .037). The GM-CSF and G-CSF+GM-CSF groups had lower 100-day transplantation-related mortality than the G-CSF group (8.8%, 8.7%, and 21.7%, respectively; P = .034). After a median follow-up of 600 days, IFD-related mortality was lower in the groups that received GM-CSF or G-CSF+GM-CSF compared with G-CSF (1.47%, 1.45%, and 11.59%, respectively; P = .016). There were no significant differences in relapse, graft-versus-host disease, or hemorrhage-related mortality among the three groups of patients.

CONCLUSION

For recipients of alloHSCT, compared with G-CSF, prophylactic GM-CSF was associated with lower 100-day transplantation-related mortality, lower 100-day cumulative mortality, and lower 600-day IFD-related mortality.

Novel PI3Kγ mutation in a 44-year-old man with chronic infections and chronic pelvic pain

A 44-year-old man is presented here with 14 years of chronic purulent sinusitis, a chronic fungal rash of the scrotum, and chronic pelvic pain. Treatment with antifungal therapy resulted in symptom improvement, however he was unable to establish an effective long-term treatment regimen, resulting in debilitating symptoms. He had undergone extensive work-up without identifying a clear underlying etiology, although Candida species were cultured from the prostatic fluid. 100 genes involved in the cellular immune response were sequenced and a missense mutation was identified in the Ras-binding domain of PI3Kγ. PI3Kγ is a crucial signaling element in leukotaxis and other leukocyte functions. We hypothesize that his mutation led to his chronic infections and pelvic pain.