Mucormycosis in lung transplant recipients: A systematic review of the literature and a case series

Factors influencing mortality in COVID-19-associated mucormycosis: The international ID-IRI study

The emergence of COVID-19, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), triggered a global pandemic. Concurrently, reports of mucormycosis cases surged, particularly during the second wave in India. This study aims to investigate mortality factors in COVID-19-associated mucormycosis (CAM) cases, exploring clinical, demographic, and therapeutic variables across mostly Asian and partly African countries. A retrospective, cross-sectional analysis of CAM patients from 22 medical centers across eight countries was conducted, focusing on the first 3 months post-COVID-19 diagnosis. Data collected through the ID-IRI included demographics, comorbidities, treatments, and outcomes. A total of 162 CAM patients were included. The mean age was 54.29 ± 13.04 years, with 54% male. Diabetes mellitus (85%) was prevalent, and 91% had rhino-orbital-cerebral mucormycosis. Surgical debridement was performed in 84% of the cases. Mortality was 39%, with advanced age (hazard ratio [HR] = 1.06, [P < .001]), rituximab use (HR = 21.2, P = .05), and diabetic ketoacidosis (HR = 3.58, P = .009) identified as risk factors. The mortality risk increases by approximately 5.6% for each additional year of age. Surgical debridement based on organ involvement correlated with higher survival (HR = 8.81, P < .001). The utilization of rituximab and diabetic ketoacidosis, along with advancing age, has been associated with an increased risk of mortality in CAM patients. A combination of antifungal treatment and surgical intervention has demonstrated a substantial improvement in survival outcomes.

Pharmacological management of invasive mold infections in solid organ transplant recipients

INTRODUCTION

Solid organ transplant (SOT) recipients face an increased susceptibility to invasive fungal infection (IFI) due to filamentous fungi. Post-transplant invasive aspergillosis (IA) and mucormycosis are related to exceedingly high mortality rates and graft loss risk, and its management involve a unique range of clinical challenges.

AREAS COVERED

First, the current treatment recommendations for IA and mucormycosis among SOT recipients are critically reviewed, including the supporting evidence. Next, we discussed particular concerns in this patient population, such as drug-drug interactions (DDIs) between triazoles and post-transplant immunosuppression or treatment-related toxicity. The role for immunomodulatory and host-targeted therapies is also considered, as well as the theoretical impact of the intrinsic antifungal activity of calcineurin inhibitors. Finally, a personal opinion is made on future directions in the pharmacological approach to post-transplant IFI.

EXPERT OPINION

Despite relevant advances in the treatment of mold IFIs in the SOT setting, such as the incorporation of isavuconazole (with lower incidence of DDIs and better tolerability than voriconazole), there remains a large room for improvement in areas such as the position of combination therapy or the optimal strategy for the reduction of baseline immunosuppression. Importantly, future studies should define the specific contribution of newer antifungal agents and classes.

Pulmonary Mucormycosis Involving the Left Main Bronchus and the Pulmonary Artery

Pulmonary mucormycosis is an extremely rare disease. It often occurs in immunocompromised patients, such as patients with diabetes and those on long-term steroid use. The prognosis of the disease is poor despite the administration of antifungal agents and removal of the necrotic tissue. Herein, we present a successfully treated case of pulmonary mucormycosis in a patient with type 2 diabetes who underwent left pneumonectomy because of the involvement of the left main pulmonary artery and the left main bronchus. Irrespective of the infected organ, complete debridement of the infected tissue and treatment with antifungal agents are essential for treating mucormycosis.

Diagnosis and Treatment of Fungal Infections in Lung Transplant Recipients

Fungal infections are a significant source of morbidity in the lung transplant population via direct allograft damage and predisposing patients to the development of chronic lung allograft dysfunction. Prompt diagnosis and treatment are imperative to limit allograft damage. This review article discusses incidence, risk factors, and symptoms with a specific focus on diagnostic and treatment strategies in the lung transplant population for fungal infections caused by Aspergillus, Candida, Coccidioides, Histoplasma, Blastomyces, Scedosporium/Lomentospora, Fusarium, and Pneumocystis jirovecii. Evidence for the use of newer triazole and inhaled antifungals to treat isolated pulmonary fungal infections in lung transplant recipients is also discussed.

The application of metagenomic next-generation sequencing in patients with infection or colonization caused by Lichtheimia species

Background

Mucormycosis is considered the fourth most common invasive fungal disease after candidiasis, aspergillosis and cryptococcosis. Lichtheimia species accounted for 5%-29% of all mucormycosis. However, available data on species-specific analysis of Lichtheimia infections are limited.

Methods

This study included nine patients hospitalized in five hospitals in two cities in south China with mucormycosis or colonization caused by Lichtheimia species, diagnosed mainly by metagenomic next-generation sequencing (mNGS). The corresponding medical records were reviewed, and the clinical data analyzed included demographic characteristics, site of infection, host factors and type of underlying disease, diagnosis, clinical course, management, and prognosis.

Results

In this study, nine patients with Lichtheimia infections or colonization had a recent history of haematological malignancy (33.3%), solid organ transplants (33.3%), pulmonary disease (22.2%), and trauma (11.1%) and were categorized as 11.1% (one case) proven, 66.7% (six cases) probable mucormycosis and 22.2% (two cases) colonization. Pulmonary mucormycosis or colonization was the predominant presentation in 77.8% of cases and mucormycosis caused by Lichtheimia resulted in death in four out of seven patients (57.1%).

Conclusion

These cases highlight the importance of early diagnosis and combined therapy for these sporadic yet life-threatening infections. Further studies on the diagnosis and control of Lichtheimia infection in China are required.

Fungal Infections in Lung Transplantation

Purpose of Review

We aim to understand the most common fungal infections associated with the post-lung transplant period, how to diagnose, treat, and prevent them based on the current guidelines published and our center’s experience.

Recent Findings

Different fungi inhabit specific locations. Diagnosis of invasive fungal infections (IFIs) depends on symptoms, radiologic changes, and a positive microbiological or pathology data. There are several molecular tests that have been used for diagnosis. Exposure to fungal prophylaxis can predispose lung transplant recipients to these emerging molds. Understanding and managing medication interactions and drug monitoring are essential in successfully treating IFIs.

Summary

With the increasing rate of lung transplantations being performed, and the challenges posed by the immunosuppressive regimen, understanding the risk and managing the treatment of fungal infections are imperative to the success of a lung transplant recipient. There are many ongoing clinical trials being conducted in hopes of developing novel antifungals.

Impact of COVID-19-associated Mucormycosis in Kidney Transplant Recipients: A Multicenter Cohort Study

BACKGROUND

COVID-19-associated mucormycosis (CAM) is a recently emerging entity. There is a lack of reports of CAM in organ transplant recipients.

METHODS

We conducted a multicenter (n = 18) retrospective research in India during November 2020 to July 2021. The purpose of this study was to explore the clinical spectrum, outcome and risk factors for mortality of CAM in kidney transplant recipients (KTRs).

RESULTS

The incidence of CAM was 4.4% (61/1382 COVID-19-positive KTRs) with 26.2% mortality. The median age of the cohort was 45 (38-54) y. Twenty (32%) were not hospitalized and 14 (22.9%) were on room air during COVID-19. The proportion of postdischarge CAM was 59.1%, while concurrent CAM was reported in 40.9%. The presentation of CAM was 91.8% rhino-orbital-cerebral mucormycosis and 8.2% pulmonary with 19.6% and 100% mortality, respectively. In the univariable analysis, older age, obesity, difficulty of breathing, high-flow oxygen requirement, and delay in starting therapy were significantly associated with mortality. In the multivariable logistic regression analysis, patients requiring high-flow oxygen therapy [odds ratio (95% confidence interval) = 9.3 (1.6-51); P = 0.01] and obesity [odds ratio (95% confidence interval) = 5.2 (1-28); P = 0.05] was associated with mortality. The median follow-up of the study was 60 (35-60) d.

CONCLUSIONS

We describe the largest case series of CAM in KTRs. Morality in pulmonary CAM is extremely high. Severe COVID-19 pose extra risk for the development of CAM and associated mortality. Our report will help in better understanding the conundrum and management of CAM.

Global Prevalence of COVID-19-Associated Mucormycosis (CAM): Living Systematic Review and Meta-Analysis

Mucormycosis, a secondary fungal infection, gained much attention in the ongoing COVID-19 pandemic. This deadly infection has a high all-cause mortality rate and imposes a significant economic, epidemiological, and humanistic burden on the patients and healthcare system. Evidence from the published epidemiological studies showed the varying prevalence of COVID-19-associated mucormycosis (CAM). This study aims to compute the pooled prevalence of CAM and other associated clinical outcomes. MEDLINE, Embase, Cochrane COVID-19 Study Register, and WHO COVID-19 databases were scanned to retrieve the relevant articles until August 2021. All studies reporting the prevalence of mucormycosis among COVID-19 patients were eligible for inclusion. Two investigators independently screened the articles against the selection criteria, extracted the data, and performed the quality assessment using the JBI tool. The pooled prevalence of CAM was the primary outcome, and the pooled prevalence of diabetes, steroid exposure, and the mortality rate were the secondary outcomes of interest. Comprehensive Meta-Analysis software version 2 was used for performing the meta-analysis. This meta-analysis comprised six studies with a pooled sample size of 52,916 COVID-19 patients with a mean age of 62.12 ± 9.69 years. The mean duration of mucormycosis onset was 14.59 ± 6.88 days after the COVID-19 diagnosis. The pooled prevalence of CAM (seven cases per 1000 patients) was 50 times higher than the highest recorded background of mucormycosis (0.14 cases per 1000 patients). A high mortality rate was found among CAM patients with a pooled prevalence rate of 29.6% (95% CI: 17.2-45.9%). Optimal glycemic control and the judicious use of steroids should be the approach for tackling rising CAM cases.

A systematic review on SARS-CoV-2-associated fungal coinfections

A severe pandemic of Coronavirus Disease (COVID‐19) has been sweeping the globe since 2019, and this time, it did not stop, with frequent mutations transforming into virulent strains, for instance, B.1.1.7, B.1.351, and B.1.427. In recent months, a fungal infection, mucormycosis has emerged with more fatal responses and significantly increased mortality rate. To measure the severity and potential alternative approaches against black fungus coinfection in COVID‐19 patients, PubMed, Google Scholar, World Health Organization (WHO) newsletters, and other online resources, based on the cases reported and retrospective observational analysis were searched from the years 2015–2021. The studies reporting mucormycosis with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS‐CoV‐2) coinfection and/or demonstrating potential risk factors, such as a history of diabetes mellitus or suppressed immune system were included, and reports published in non‐English language were excluded. More than 20 case reports and observational studies on black fungus coinfection in COVID‐19 patients were eligible for inclusion. The results indicated that diabetes mellitus, hyperglycemic, and immunocompromised COVID‐19 patients with mucormycosis were at a higher risk. We found that it was prudent to assess the potential risk factors and severity of invasive mycosis via standardized diagnostic and clinical settings. Large‐scale studies need to be conducted to identify early biomarkers and optimization of diagnostic methods has to be established per population and geographical variation. This will not only help clinicians around the world to detect the coinfection in time but also will prepare them for future outbreaks of other potential pandemics.

Observational studies and case reports of Post‐COVID black fungus co‐infection highlighted in review.

Along with risk factors, radiological interventions of black fungus co‐infection in COVID‐19 patients and challenges for accurate diagnosis were elaborated.

The review discusses interconnection between fungus and SARS‐CoV‐2 co‐infection of mechanism to identify potential biomarkers.

Our conclusion will contribute to motivate researchers to design follow‐up plans for black fungus infection in COVID‐19.

Fungal Infection in Lung Transplantation

Invasive fungal infections threaten lung transplant outcomes with high associated morbidity and mortality. Pharmacologic prophylaxis may be key to prevent posttransplant invasive fungal infections, but cost, adverse effects, and absorption issues are barriers to effective prophylaxis. Trends in fungal infection diagnostic strategies utilize molecular diagnostic methodologies to complement traditional histopathology and culture techniques. While lung transplant recipients are susceptible to a variety of fungal pathogens, Candida spp. and Aspergillus spp. infections remain the most common. With emerging resistant organisms and multiple novel antifungal agents in the research pipeline, it is likely that treatment strategies will continue to evolve.

Has the mortality from pulmonary mucormycosis changed over time? A systematic review and meta-analysis

OBJECTIVES

Pulmonary mucormycosis (PM) is increasingly being reported in immunocompromised patients and has a high mortality. Our aim was to assess the mortality of PM and its trend over time. We also evaluated the role of combined medical-surgical therapy in PM.

METHODS

We performed a systematic review of Pubmed, Embase, and Cochrane central databases. Studies were eligible if they described at least five confirmed cases of PM and reported mortality. We also assessed the effect of combined medical-surgical therapy versus medical treatment alone on PM mortality. We used a random-effects model to estimate the pooled mortality of PM and compared it across three time periods. The factors influencing mortality were assessed using meta-regression. We evaluated the risk difference (RD) of death in the following: subjects undergoing combined medical-surgical therapy versus medical therapy alone, subjects with isolated PM versus disseminated disease, and PM in diabetes mellitus (DM) versus non-DM as a risk factor.

RESULTS

We included 79 studies (1544 subjects). The pooled mortality of PM was 57.1% (95% confidence interval [CI] 51.7-62.6%). Mortality improved significantly over time (72.1% versus 58.3% versus 49.8% for studies before 2000, 2000-2009, and 2010-2020, respectively, p 0.00001). This improved survival was confirmed in meta-regression after adjusting for the study design, the country's income level, and the sample size. Combined medical-surgical therapy was associated with a significantly lower RD (95%CI) of death: -0.32 (-0.49 to -0.16). The disseminated disease had a higher risk of death than isolated PM, but DM was not associated with a higher risk of death than other risk factors.

CONCLUSIONS

While PM is still associated with high mortality, we noted improved survival over time. Combined medical-surgical therapy improved survival compared to medical treatment alone.

Understanding rare infections post-lung transplantation

Introduction: Lung transplant recipients are at the highest risk of infectious complications among all solid-organ transplant (SOT) recipients. In the current era, many standardized protocols in terms of diagnostic algorithms, prophylaxis, and therapeutic strategies have improved the management of the most common infectious complications. Conversely, diagnosis of rare infections can be particularly challenging and this can delay appropriate treatment.Areas covered: This article will review the epidemiology, clinical presentation, diagnostic and therapeutic management of certain rarely reported viral, fungal, bacterial and parasitic infections in lung transplant recipients.Expert opinion: Once the most frequent infections are excluded, clinical suspicion combined with molecular diagnostic methods such as targeted and broad-spectrum PCRs can allow diagnosis of a rare infection. A multidisciplinary team, including transplant pulmonologists, transplant infectious diseases specialists, microbiologists and pathologists is essential for prompt diagnosis and optimal therapeutic management.