Unique Characteristics of Fungal Infections in Lung Transplant Recipients

Voriconazole Therapeutic Drug Monitoring Among Lung Transplant Recipients Receiving Targeted Therapy for Invasive Aspergillosis

BACKGROUND

Voriconazole is the first line treatment for invasive aspergillosis (IA) Current guidelines suggest performing regular voriconazole therapeutic drug monitoring (TDM) to optimize treatment efficacy. We aimed to determine if TDM was predictive of clinical outcome in LTRs.

METHODS

Retrospective chart review was performed for all LTRs with probable or proven IA, treated with voriconazole monotherapy and who underwent TDM during therapy. Clinical outcome and toxicity were measured at 12 weeks. Classification and regression tree (CART) analysis was used to determine the most predictive voriconazole level thresholds for successful outcome.

RESULTS

118 TDM samples from 30 LTRs with IA were analyzed. Three LTRs were excluded due to early treatment discontinuation. The median TDM level was 1.2 μg/mL (range 0.06-7.3). At 12 weeks, 62% (17/27) of patients had a successful outcome, while 37% (10/27) of patients failed therapy. CART analysis determined that the best predictor for successful outcome was a median TDM level > 0.72 μg/mL. Seventy percent (14/20) of patients with median TDM above 0.72 μg/mL had a successful outcome, compared to 42.9% (3/7) of patients with a median TDM below 0.72 μg/mL (OR 3.11; 95% CI: 0.53-20.4; P = 0.21). CART analysis determined that a TDM level greater than 2.13 μg/mL was predictive of hepatotoxicity.

CONCLUSIONS

Our data suggests that a voriconazole TDM range between 0.72 μg/mL and 2.13 μg/mL may be associated with improved outcomes. Our study is in line with current recommendations on the use of voriconazole TDM in improving outcome and minimizing toxicity in LTR with IA. This article is protected by copyright. All rights reserved.

Invasive fungal infections in transplant recipients

Invasive fungal infections are an important cause of morbidity and mortality in hematopoietic stem cell transplant and solid organ transplant recipients. Evolving transplant modalities and techniques, complex and extensive immunosuppressant strategies, and the increased use of broad spectrum antifungal prophylaxis has greatly impacted the epidemiology and temporal pattern of invasive fungal infections in the transplant population. The goal of this article is to provide an up-to-date review of the most commonly encountered invasive fungal infections seen in transplant recipients, including epidemiology, risk factors, clinical features, diagnostic dilemmas, management and their overall influence on outcomes.

Invasive mould infections in newborns and children

Invasive mould infections represent important complications of different pediatric conditions. Epidemiology and clinical features vary according to the type of underlying conditions that determine the risk of invasive mycosis. No pediatric study has specifically evaluated the efficacy of prophylaxis or therapy invasive moulds infections, while pediatric dosages for the treatment of invasive aspergillosis are available for drugs that produced positive results in clinical trials undertaken in adults.

Prophylactic Antifungal Agents Used After Lung Transplantation

Objective:

To review the data supporting available antifungal agents and compare regimens utilized to prevent fungal infection in lung transplant recipients.

Data Sources:

Literature retrieval was accessed through MEDLINE (1950 through October 2009) and United Network for Organ Sharing online database (available data through October 2009), using the terms lung transplantation, prophylaxis, and fungal infection. In addition, reference citations from publications identified were reviewed.

Study Selection And Data Extraction:

All articles or related abstracts in English identified from the data sources above were evaluated. Literature including adult lung transplant recipients who received systemic antifungal prophylaxis to prevent invasive fungal infections (IFIs) was included in the review.

Data Synthesis:

IFIs after lung transplantation remain a common postoperative problem and are associated with high mortality. The lung is the most vulnerable solid organ to be transplanted, as it is the main organ responsible for gas exchange and therefore the high risk for pulmonary-related IFIs. It is most susceptible to developing an IFI, as it serves as a medium for organisms traveling from air to human tissue, potentially causing life-threatening infections. Such infections typically involve Candida and Aspergillus spp. and tend to occur within the first 12 months after transplant. Although there has been an increase in lung transplants performed over the past decade, no standard antifungal prophylactic regimen exists. Literature describing antifungals used to prevent IFI after transplant is scarce, which may be due to a lack of consistency in regimens used between transplant centers. Several regimens have been described utilizing different antifungal agents as both monotherapy and combination therapy. The majority of the literature reviewed here describes aerosolized amphotericin B formulations and azole antifungals demonstrating an overall decreased risk of fungal infection after lung transplantation. It has become the standard of practice to initiate some form of antifungal prophylaxis in these patients.

Conclusions:

The risk of fungal infection after lung transplant is multifactorial and optimal prophylactic regimens should include agents with adequate activity against the most pathogenic fungi.