Using routine blood parameters to anticipate clinical outcomes in invasive aspergillosis.

OBJECTIVE: In invasive aspergillosis (IA), monitoring response to antifungal treatment is challenging. We aimed to explore if routine blood parameters help to anticipate outcomes following IA. METHODS: Post hoc secondary analysis of two multicenter randomized trials was performed. The Global Comparative Aspergillosis Study (GCA, n = 123) and the Combination Antifungal Study (CAS, n = 251) constituted the discovery and validation cohorts respectively. The outcome measures were response to treatment and survival to 12 weeks. Interval platelet, galactomannan index (GMI) and C-reactive protein (CRP) levels prior and during antifungal treatment were analysed using logistic regression, Kaplan-Meier survival and receiver operating characteristic (ROC) analyses. RESULTS: The 12-week survival was 70.7% and 63.7% for the GCA and CAS cohorts respectively. In the GCA cohort, every 10 × 109/L platelet count increase at week 2 and 4 improved 12-week survival odds by 6-18% (odds ratio (OR) 1.06-1.18, 95% confidence interval (CI) 1.02-1.33). Survival odds also improved 13% with every 10 mg/dL CRP drop at week 1 and 2 (OR 0.87, 95% CI 0.78-0.97). In the CAS cohort, week 2 platelet count was also associated with 12-week survival with 10% improved odds for every 10 × 109/L platelet increase (OR, 1.10, 95% CI 1.04-1.15). A GMI drop of 0.1 unit was additionally found to increase the odds of treatment response by 3% at the baseline of week 0 (OR 0.97, 95% CI 0.95-0.99). Week 2 platelet and CRP levels performed better than GMI on ROC analyses for survival (area under ROC curve 0.76, 0.87 and 0.67 respectively). A baseline platelet count higher than 30 × 109/L clearly identified patients with >75% survival probability. CONCLUSIONS: Higher serial platelets were associated with overall survival while GMI trends were linked to IA treatment response. Routine and simple laboratory indices may aid follow-up of response in IA patients.

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

Macrophages are known to be involved in pathogen recognition and mediate host immune responses, but, in the clinical setting, their purported central role in opportunistic fungal infections has not been demonstrated to date. Herein, we describe a patient with invasive testicular aspergillosis in whom we found, for the first time, a defect in macrophage function.

Regulation of cytokine responses by seasonality of vitamin D status in healthy individuals.

The immune modulating capacity of vitamin D(3) is well-recognized. Ultra-violet (UV) exposure determines production of vitamin D(3) in vivo and varies through the course of the year, especially in temperate regions. However, it is not known whether the human innate immune response differs due to seasonality. To validate the seasonal effects of vitamin D(3) , the effect of 1,25(OH)(2) D(3) on peripheral blood mononuclear cells (PBMC) cytokine response was first determined in vitro. 1,25(OH)(2) D(3) decreased interleukin (IL)-6 and tumour necrosis factor (TNF)-α release by PBMC stimulated with tripalmitoyl-S-glycerylcysteine (Pam3Cys) or lipopolysaccharide (LPS). Subsequently, ex-vivo stimulation studies were performed in 15 healthy volunteers through the course of the four seasons of the year. PBMC were isolated and stimulated with Toll-like receptor (TLR)-2 and TLR-4 ligands Pam3Cys and LPS, respectively. Circulating concentrations of 25(OH)D(3) and 1,25(OH)(2) D(3) were higher during summer (P<0·05) and a down-regulation of TLR-4-mediated IL-1ß, IL-6, TNF-α, interferon (IFN)-γ and IL-10 production in summer was observed compared to winter (P<0·05). The variation in cytokine response upon TLR-2 (Pam3Cys) stimulation was moderate throughout the four seasons. The repressed cytokine production during the summer months could be explained partly by the reduced cell-membrane expression of TLRs. Physiological variation in vitamin D(3) status through the four seasons of the year can lead to alteration in the innate immune responses. Elevated vitamin D(3) level in vivo is associated with down-regulation of cytokine response through diminished surface expression of pattern recognition receptors.

Therapeutic plasmapheresis for the treatment of the thrombotic thrombocytopenic purpura-haemolytic uraemic syndromes.

INTRODUCTION: The thrombotic thrombocytopenic purpura-haemolytic uraemic syndromes (TTP-HUS) are uncommon disorders that are fatal if untreated. Therapeutic plasma exchange has resulted in excellent remission and survival rates in this patient population. METHODS: We reviewed our experience of therapeutic plasmapheresis for TTP-HUS syndromes for 11 patients who presented in the last five years. Parameters captured included haemoglobin and platelet counts at presentation as well as the number of plasmapheresis sessions and adjunctive treatment given. RESULTS: We found a response rate of 82 percent to plasma exchange, of whom 55 percent attained complete remission. Responses were excellent in the five patients who presented with primary or idiopathic TTP (100 percent response) among whom 80 percent had sustained long term responses. Responses were poor and often unsustained (only one out of six survived) in patients who presented with thrombotic microangiopathies secondary to underlying disorders such as bone marrow transplantation and metastatic carcinoma. CONCLUSION: Plasmapheresis is mandatory and extremely effective for primary TTP. However, it is at most an adjunct for patients who developed it secondary to an underlying disorder until and if the primary disorder can be successfully treated.