Risk factors for the development of invasive aspergillosis after kidney transplantation: Systematic review and meta-analysis

Risk Factors for Early Fungal Disease in Solid Organ Transplant Recipients: A Systematic Review and Meta-analysis

BACKGROUND

Invasive fungal infections are associated with high morbidity in solid organ transplant recipients. Risk factor modification may help with preventative efforts. The objective of this study was to identify risk factors for the development of fungal infections within the first year following solid organ transplant.

METHODS

We searched for eligible articles through February 3, 2023. Studies published after January 1, 2001, that pertained to risk factors for development of invasive fungal infections in solid organ transplant were reviewed for inclusion. Of 3087 articles screened, 58 were included. Meta-analysis was conducted using a random-effects model to evaluate individual risk factors for the primary outcome of any invasive fungal infections and invasive candidiasis or invasive aspergillosis (when possible) within 1 y posttransplant.

RESULTS

We found 3 variables with a high certainty of evidence and strong associations (relative effect estimate ≥ 2) to any early invasive fungal infections across all solid organ transplant groups: reoperation (odds ratio [OR], 2.92; confidence interval [CI], 1.79-4.75), posttransplant renal replacement therapy (OR, 2.91; CI, 1.87-4.51), and cytomegalovirus disease (OR, 2.97; CI, 1.78-4.94). Both posttransplant renal replacement therapy (OR, 3.36; CI, 1.78-6.34) and posttransplant cytomegalovirus disease (OR, 2.81; CI, 1.47-5.36) increased the odds of early posttransplant invasive aspergillosis. No individual variables could be pooled across groups for invasive candidiasis.

CONCLUSIONS

Several common risk factors exist for the development of any invasive fungal infections in solid organ transplant recipients. Additional risk factors for invasive candidiasis and aspergillosis may be unique to the pathogen, transplanted organ, or both.

Age difference of patients with and without invasive aspergillosis: a systematic review and meta-analysis

BACKGROUND

Invasive Aspergillosis (IA) is a life-threatening fungal disease with significant mortality rates. Timely diagnosis and treatment greatly enhance patient outcomes. This study aimed to explore the association between patient age and the development of IA, as well as the potential implications for risk stratification strategies.

METHODS

We searched National Center for Biotechnology Information (NCBI) databases for publications until October 2023 containing age characteristics of patients with and without IA. A random-effects model with the application of inverse-variance weighting was used to pool reported estimates from each study, and meta-regression and subgroup analyses were utilized to assess sources of heterogeneity.

RESULTS

A systematic review was conducted, resulting in the inclusion of 55 retrospective observational studies with a total of 13,983 patients. Meta-analysis revealed that, on average, patients with IA were approximately two and a half years older (95% Confidence Interval [CI] 1.84-3.31 years; I2 = 26.1%) than those without the disease (p < 0.0001). No significant moderators could explain the observed heterogeneity in age difference. However, subgroup analysis revealed that age differences were more pronounced within particular patient groups compared to others. For example, patients with and without IA who had primary severe lung infections exhibited a greater difference in mean age than other patient cohorts.

CONCLUSIONS

Further research, such as individual patient data meta-analysis, is necessary to better understand the potential relationship between increasing age and the likelihood of IA. Improved risk stratification strategies based on patient age could potentially enhance the early detection and treatment of IA, ultimately improving patient outcomes.

Invasive pulmonary aspergillosis following human metapneumovirus infection in solid-organ transplant recipients: Another virus to add to the list

There is increasing recognition that respiratory viral infections such as influenza, respiratory syncytial virus, parainfluenza virus, adenovirus, and SARS-CoV-2 can promote the development of invasive fungal pulmonary coinfections, particularly invasive aspergillosis, both in immunocompetent and immunocompromised patients. To date, there are no case reports exploring the role of human metapneumovirus as a risk factor for fungal coinfection. Below, we describe the case of a 63-year-old woman who received a kidney transplant and developed invasive pulmonary aspergillosis after a human metapneumovirus infection and discuss the possible phenomena that could favor this association.

Isavuconazole for Treating Invasive Mould Disease in Solid Organ Transplant Recipients

Solid organ transplant (SOT) recipients have a higher risk of developing invasive mould diseases (IMD). Isavuconazole is a novel broad-spectrum azole active against Aspergillus spp. and Mucor, well tolerated, with an excellent bioavailability and predictable pharmacokinetics, that penetrates in most tissues rapidly, and has few serious adverse effects, including hepatic toxicity. Contrary to other broad-spectrum azoles, such as voriconazole and posaconazole, isavuconazole appears to show significant smaller drug-drug interactions with anticalcineurin drugs. We have performed an extensive literature review of the experience with the use of isavuconazole in SOT, which included the SOTIS and the ISASOT studies, and published case reports. More than 140 SOT recipients treated with isavuconazole for IMD were included. Most patients were lung and kidney recipients treated for an Aspergillus infection. Isavuconazole was well tolerated (less than 10% of patients required treatment discontinuation). The clinical responses appeared comparable to that found in other high-risk patient populations. Drug-drug interactions with immunosuppressive agents were manageable after the reduction of tacrolimus and the adjustment of mTOR inhibitors at the beginning of treatment. In conclusion, isavuconazole appears to be a reasonable option for the treatment of IMD in SOT. More clinical studies are warranted.

Invasive aspergillosis in adult patients in Australia and New Zealand: 2017-2020

Background

New and emerging risks for invasive aspergillosis (IA) bring the need for contemporary analyses of the epidemiology and outcomes of IA, in order to improve clinical practice.

Methods

The study was a retrospective, multicenter, cohort design of proven and probable IA in adults from 10 Australasian tertiary centres (January 2017-December 2020). Descriptive analyses were used to report patients' demographics, predisposing factors, mycological characteristics, diagnosis and management. Accelerated failure-time model was employed to determine factor(s) associated with 90-day all-cause mortality (ACM).

Findings

Of 382 IA episodes, 221 (in 221 patients) fulfilled inclusion criteria - 53 proven and 168 probable IA. Median patient age was 61 years (IQR 51-69). Patients with haematologic malignancies (HM) comprised 49.8% of cases. Fifteen patients (6.8%) had no pre-specified immunosuppression and eleven patients (5.0%) had no documented comorbidity. Only 30% of patients had neutropenia. Of 170 isolates identified, 40 (23.5%) were identified as non-Aspergillus fumigatus species complex. Azole-resistance was present in 3/46 (6.5%) of A. fumigatus sensu stricto isolates. Ninety-day ACM was 30.3%. HM (HR 1.90; 95% CI 1.04-3.46, p = 0.036) and ICU admission (HR 4.89; 95% CI 2.93-8.17, p < 0.001) but not neutropenia (HR 1.45; 95% CI 0.88-2.39, p = 0.135) were associated with mortality. Chronic kidney disease was also a significant predictor of death in the HM subgroup (HR 3.94; 95% CI 1.15-13.44, p = 0.028).

Interpretation

IA is identified in high number of patients with mild/no immunosuppression in our study. The relatively high proportion of non-A. fumigatus species complex isolates and 6.5% azole-resistance rate amongst A. fumigatus sensu stricto necessitates accurate species identification and susceptibility testing for optimal patient outcomes.

Funding

This work is unfunded. All authors' financial disclosures are listed in detail at the end of the manuscript.

Approach to the diagnosis of invasive fungal infections of the respiratory tract in the immunocompromised host

PURPOSE OF REVIEW

The burden of invasive fungal infection is increasing worldwide, largely due to a growing population at-risk. Most serious human fungal pathogens enter the host via the respiratory tract. Early identification and treatment of invasive fungal respiratory infections (IFRIs) in the immunocompromised host saves lives. However, their accurate diagnosis is a difficult challenge for clinicians and mortality remains high.

RECENT FINDINGS

This article reviews IFRIs, focussing on host susceptibility factors, clinical presentation, and mycological diagnosis. Several new diagnostic tools are coming of age including molecular diagnostics and point-of-care antigen tests. As diagnosis of IFRI relies heavily on invasive procedures like bronchoalveolar lavage and lung biopsy, several novel noninvasive diagnostic techniques are in development, such as metagenomics, 'volatilomics' and advanced imaging technologies.

SUMMARY

Where IFRI cannot be proven, clinicians must employ a 'weights-of-evidence' approach to evaluate host factors, clinical and mycological data. Implementation studies are needed to understand how new diagnostic tools can be best applied within clinical pathways. Differentiating invasive infection from colonization and identifying antifungal resistance remain key challenges. As our diagnostic arsenal expands, centralized clinical mycology laboratories and efforts to ensure access to new diagnostics in low-resource settings will become increasingly important.

Post-transplantation cutaneous and renal Aspergillus infection

A renal transplant recipient aged 68 years experienced multiple complications after an initial good graft function from a deceased donor transplant. Late in the first week, the patient was oliguric with hematuria; the graft failed in week 2 after the development of a hematoma from a rupture of a renal artery aneurysm. He had a recurrent bleed from the internal iliac graft site and subsequently developed painful dark patches on his leg, distal to where the transplant had been. Histology from the explanted graft and skin biopsies demonstrated Aspergillus flavus; this was also grown in the culture of the external iliac artery tissue. Systemic aspergillosis is rare but well recognized, especially in the immunocompromised. Presentations include mycotic aneurysms and secondary cutaneous aspergillosis from hematogenous spread. Diagnosis requires confirmation by histology or direct culture, but a high β-glucan concentration and positive galactomannan antigen can suggest invasive fungal infection in the early stages of the disease. Cases should be managed with systemic antifungals and involvement of local microbiology services; unfortunately, the prognosis is poor.

Antifungal stewardship in solid organ transplantation

BACKGROUND

Antifungal stewardship (AFS) has emerged as an important component of quality in managing invasive fungal infections (IFIs), and cost-benefit calculations suggest regular training in AFS is well worth the effort.

METHODS

This review will discuss the most common IFIs in solid organ transplantation (SOT)-recipients, how to diagnose them, and current recommendations for antifungal treatment and prophylaxis before demonstrating key takeaway points of AFS in this high-risk population.

RESULTS

Effective AFS starts before a patient is admitted for SOT, through education and regular interactions of the interdisciplinary clinical team involved in patient management, considering local factors such as epidemiological data and knowledge of diagnostic options including local turnaround times. Understanding the spectrum of antifungal agents, their efficacy and safety profiles, and pharmacokinetics, as well as duration of therapy is hereby essential. The most frequent IFIs in SOT recipients are caused by Candida species, followed by Aspergillus species, both with increasing resistance rates. Diagnosis of IFI can be challenging due to unspecific clinical presentation and difficult interpretation of microbiological findings and biomarkers. Prophylactic strategies, such as those for invasive aspergillosis in lung transplantation or invasive candidiasis (IC) in certain liver transplant settings, as well as the selection of the appropriate therapeutic agents require detailed knowledge on the pharmacokinetics and drug-drug interactions of antifungals.

CONCLUSIONS

Here in this review, we address what constitutes good AFS in this heterogeneous field of solid organ transplant recipients.

Association of COVID-19-Associated Pulmonary Aspergillosis with Cytomegalovirus Replication: A Case–control Study

Introduction: Cytomegalovirus (CMV) infection is a well-known factor associated with invasive aspergillosis in immunocompromised hosts. However, its association with COVID-19-associated pulmonary aspergillosis (CAPA) has not been described. We aimed to examine the possible link between CMV replication and CAPA occurrence. Methods: A single-center, retrospective case–control study was conducted. A case was defined as a patient diagnosed with CAPA according to 2020 ECMM/ISHAM consensus criteria. Two controls were selected for each case among critically ill COVID-19 patients. Results: In total, 24 CAPA cases were included, comprising 14 possible CAPA and 10 probable CAPA. Additionally, 48 matched controls were selected. CMV replication was detected more frequently in CAPA than in controls (75.0% vs. 35.4%, p = 0.002). Probable CMV end-organ disease was more prevalent in CAPA (20.8% vs. 4.2%, p = 0.037). After adjusting for possible confounding factors, CMV replication persisted strongly associated with CAPA (OR 8.28 95% CI 1.90–36.13, p = 0.005). Among 11 CAPA cases with CMV PCR available prior to CAPA, in 9 (81.8%) cases, CMV replication was observed prior to CAPA diagnosis. Conclusions: Among critically ill COVID-19 patients, CMV replication was associated with CAPA and could potentially be considered a harbinger of CAPA. Further studies are needed to confirm this association.

Neutrophile-to-Lymphocyte Ratio as a Predictor of Mortality and Response to Treatment in Invasive Aspergillosis among Heart Transplant Recipients—Exploratory Study

Background and objective: Aspergillus pulmonary infections are potentially life-threatening complications that can occur after heart transplantation. The aim of the study was to find an easily available mortality predictor during Aspergillosis infection therapy following heart transplantation. Materials and methods: This study involved 15 heart recipients with the mean age of 55 ± 6 years who were diagnosed with invasive aspergillosis (IA) in a mean time of 80 ± 53 (19–209) days after orthotropic heart transplantation. Results: Out of fifteen patients diagnosed with IA, five died. The mean time from diagnosis to death in the deceased group was 28 ± 18 days. They were diagnosed with IA in a mean time of 80 ± 53 (19–209) days after orthotropic heart transplantation. During the initial seven days of therapy, the neutrophil to lymphocyte ratio (NLR) significantly differed between the two groups on day three and day seven, with median values of 10.8 [4.3–17.0] vs. 20.2 [17.4–116.8] (p = 0.0373) and 5.2 [3.2–8.1] vs. 32.2 [13.5–49.9] (p = 0.0101) in the survivor and the deceased group, respectively. The NLR was a significant predictor of death both on day three (cut-off point 17.2) and day seven (cut-off point 12.08) of therapy. Conclusions: Findings in our study indicate that NLR may be of predictive value in the estimation of mortality risk or response to treatment among patients with invasive aspergillosis following heart transplantation.

A Comparative Analysis of Mucormycosis in Immunosuppressed Hosts Including Patients with Uncontrolled Diabetes in the Southwest United States

BACKGROUND

Mucormycosis (zygomycosis) is an invasive fungal infection that carries a high risk of morbidity and mortality. Uncontrolled diabetes mellitus and other immunocompromising conditions are risk factors for mucormycosis development. We here describe the differences in characteristics and outcomes of mucormycosis among solid organ transplant, hematological malignancy, and diabetes mellitus groups at our institution.

METHODS

We conducted a retrospective chart review over the period of 2009-2020, with identifying patients using the International Classification of Diseases, Ninth and Tenth Revisions. Clinical, laboratory, and outcome data were collected.

RESULTS

There were 28 patients identified: 7 solid organ transplant, 3 hematological malignancy, and 18 diabetes mellitus patients were included in the study. Three solid organ transplant patients experienced an episode of rejection, and another 3 had cytomegalovirus infection prior to presenting with mucormycosis. Four of seven solid organ transplant patients had a history of diabetes mellitus, but the median hemoglobin A1C was lower than in the diabetes mellitus group (6.3 vs 11.5; P = .006). The mortality rate difference between solid organ transplant and diabetes mellitus was not statistically significant: 2/7 (28.57%) vs 5/18 (27.78%); P = .66. Patients with bilateral disease (pulmonary or sinus) had significantly higher mortality (80% vs 13%, P = .008). There was no difference in mortality outcomes among the different types of antifungal therapies administered.

CONCLUSION

A multispecialty approach is imperative in mucormycosis therapy. While the underlying risk factors were different, the outcomes were comparable for the solid organ transplant and diabetes mellitus groups. Future larger and longitudinal studies are recommended.

Coronavirus Disease 2019 and Kidney Transplantation in Saudi Arabia: Outcomes and Future Opportunities

BACKGROUND Kidney transplant services all over the world were severely impacted by the coronavirus disease 2019 pandemic. The optimum management of kidney transplant recipients with coronavirus disease 2019 remains uncertain. MATERIAL AND METHODS We conducted a multicenter cohort study of kidney transplant recipients with coronavirus disease 2019 infection in Saudi Arabia. Multivariable Cox regression analysis was used to study predictors of graft and patient outcomes at 28 days after coronavirus disease 2019 diagnosis. RESULTS We included 130 kidney transplant recipients, with a mean age of 48.7(±14.4) years. Fifty-nine patients were managed at home with daily follow-up utilizing a dedicated clinic, while 71 (54.6%) required hospital admission. Acute kidney injury occurred in 35 (26.9%) patients. Secondary infections occurred in 38 (29.2%) patients. SARS-CoV-2 antibodies testing was carried out in 84 patients, of whom 70 tested positive for IgG and/or IgM. Fourteen patients died (10.8%). A multivariable Cox regression analysis showed that age, creatinine at presentation, acute kidney injury, and use of azithromycin were significantly associated with worse patient survival. Graft loss was associated with requiring renal replacement therapy and development of secondary infections. CONCLUSIONS Despite kidney transplant recipients with coronavirus disease 2019 infection having higher rate of hospital admission and mortality compared to the general population, a significant number of them can be managed using a telemedicine clinic. Most kidney transplant patients seem to mount an antibody response following coronavirus disease 2019 infection, and it remains to be seen if they will have a similar response to the incoming vaccines.