Loss of Coordinated Neutrophil Responses to the Human Fungal Pathogen, Candida albicans, in Patients With Cirrhosis

Abstract

Neutrophils are the most abundant white blood cell in the body and are key participants in the defense against fungal infections. Fungal infections occur often in patients with cirrhosis and are associated with increased 30‐day and 90‐day mortality. Previous studies have shown that specific neutrophil functions are abnormal in patients with cirrhosis, although the extent of neutrophil dysfunction is not well understood. We tested the ability of neutrophils from 21 hospitalized patients with cirrhosis and 23 healthy control patients to kill Candida albicans, a common fungal pathogen in patients with cirrhosis. Using an assay, we also measured the ability of neutrophils to coordinate multicellular, synchronized control of C. albicans hyphae through a process known as swarming. We found that neutrophils from patients with cirrhosis have significantly decreased fungicidal capacity compared with healthy control neutrophils (53% vs. 74%, P < 0.0001) and diminished ability to control hyphal growth normalized as a ratio to healthy control (0.22 vs. 0.65, P < 0.0001). Moreover, serum from patients with cirrhosis decreases the ability of healthy control neutrophils to kill C. albicans (from 60% to 41%, P < 0.003). Circulating concentration of the inflammatory cytokines tumor necrosis factor α, interleukin‐6, and interleukin‐8 were found to be significantly elevated in patients with cirrhosis compared to healthy controls. Following pretreatment with granulocyte‐colony stimulating factor and granulocyte‐macrophage colony‐stimulating factor, neutrophil function was restored to almost that of healthy controls. Conclusion: Our data establish profound neutrophil dysfunction against, and altered swarming to, C. albicans in patients with cirrhosis. This dysfunction can be partially reversed with cytokine augmentation ex vivo.

Host defense against fungal pathogens: Adaptable neutrophil responses and the promise of therapeutic opportunities?

“…Here, the swarming assay was leveraged to dissect the abilities of circulating neutrophils to mobilize and contain C. albicans growth where healthy neutrophils swarmed and effectively restricted fungal growth while cirrhotic patient neutrophils failed to contain C. albicans. In contrast, neutrophils from transplant patients displayed more heterogeneity between patients in the ability of their swarms to restrict fungi [30,31]. We found that human disease alters the whole population of circulating neutrophils independent of disease severity; however, one limitation of the assay is the difficulty in parsing out individual neutrophils to follow their response to the target over time.…”

“…These patient-based data are promising as these suggest that specific numbers of granulocyte subpopulations lead to improved immune-based therapies. Given evidence of specific human neutrophil subpopulations [30,31], these data suggest that the higher dose is effective because either patients require a large number of granulocytes overall or the higher dose may have contained a degree of specific neutrophil subpopulations.…”

Infections in Alcoholic Hepatitis

“…This defect may be due to neutrophil exhaustion in the setting of persistently elevated circulating levels of inflammatory cytokines. 56 Patients with sAH present a more markedly reduced neutrophil antimicrobial activity, including phagocytosis and oxidative burst. 21 This underlying immune dysfunction in patients with AH may explain the lack of neutrophil functioning, thus increased prevalence of candidemia.…”

TLR Signaling Rescues Fungicidal Activity in Syk-Deficient Neutrophils

“…To confirm the purity of neutrophils at the end of the isolation process, WrightGiemsa staining (Thermo Fisher Scientific) was performed as previously reported and viabilities were verified via live/dead staining with acridine orange/propidium iodine staining and counting on the LUNA automated fluorescent cell counter at a 1:10 dilution. Both were reported at or above 87% (31,32).…”