Invasive aspergillosis in hematopoietic stem cell and solid organ transplantation

Surgical treatment of invasive pulmonary fungal infections in immunocompromised pediatric patients: Aspergillus spp. and other emerging fungi

PURPOSE

Invasive Pulmonary Fungal Infections (IPFIs) represent a diagnostic and therapeutic challenge. The exact role of surgery is not well defined. This study analyzes our experience with surgical treatment of IPFI in immunocompromised pediatric patients and, secondarily, compares IPFI caused by Aspergillus spp. with other fungal infections.

METHODS

This is a retrospective review (2000-2019) of patients with IPFI surgically treated at our pediatric institution. Statistical analysis was used to compare data between Aspergillus spp. and non-Aspergillus IPFI.

RESULTS

Twenty-five patients (64% female) underwent 29 lung resections. Median age at surgery was 7.19 years (1.63-19.14). The most frequent underlying condition (64%) was acute leukemia. Surgical indications included persistence or worsening of symptoms and pathological image findings (52%) or asymptomatic suspicious lesions in patients scheduled for intensive cytotoxic treatments or hematopoietic stem cell transplantation (48%). All patients underwent atypical lung resections, except one lobectomy. Aspergillus spp. was the most frequently isolated pathogen (68%). Follow-up was 4.07 years (0.07-18.07). Surgery-related mortality was 0%, but 4 patients died in the 100 days following surgery (2 due to disseminated fungal infection); the remaining 21 did not show signs of IPFI recurrence. Non-specific consolidations on CT scan were more frequent in non-Aspergillus IPFI (p < 0.05).

CONCLUSION

Surgical treatment of IPFI should be considered as a part of the treatment in selected pediatric immunocompromised patients, and it may have both diagnostic and therapeutic advantages over non-surgical management. When there is clinical suspicion of IPFI but CT scan shows unspecific alterations, the possibility of a non-Aspergillus IPFI should be considered.

Evaluation of the Sensititre YeastOne and Etest in Comparison with CLSI M38-A2 for Antifungal Susceptibility Testing of Three Azoles, Amphotericin B, Caspofungin, and Anidulafungin, against Aspergillusfumigatus and Other Species, Using New Clinical Breakpoints and Epidemiological Cutoff Values

Aspergillosis is an invasive fungal disease associated with high mortality. Antifungal susceptibility testing (AFST) is receiving increasing consideration for managing patients, as well as for surveilling emerging drug resistance, despite having time-consuming and technically complex reference methodologies. The Sensititre YeastOne (SYO) and Etest methods are widely utilized for yeasts but have not been extensively evaluated for Aspergillus isolates. We obtained Posaconazole (POS), Voriconazole (VCZ), Itraconazole (ITC), Amphotericin B (AMB), Caspofungin (CAS), and Anidulafungin (AND) minimum inhibitory concentrations (MICs) for both the Etest (n = 330) and SYO (n = 339) methods for 106 sequenced clinical strains. For 84 A. fumigatus, we analyzed the performance of both commercial methods in comparison with the CLSI-AFST, using available cutoff values. An excellent correlation could be demonstrated for Etest-AMB and Etest-VCZ (p < 0.01). SYO-MICs of AMB, VCZ, and POS resulted in excellent essential agreement (>93%), and >80% for AMB, VCZ, and ITC Etest-MICs. High categoric agreement was found for AMB, ITC, and CAS Etest-MICs (>85%) and AMB SYO-MICs (>90%). The considerable number of major/very major errors found using Etest and SYO, possibly related to the proposed cutoffs and associated with the less time-consuming processes, support the need for the improvement of commercial methods for Aspergillus strains.

Imaging features of fungal pneumonia in haematopoietic stem cell transplant patients

Patients who have received haematopoietic stem cell transplantation (HSCT) have a high rate of pulmonary complications, and in this immunosuppressed population, fungal pneumonia is of great concern. Fungal pneumonia can have a similar appearance to non-infectious pulmonary processes in HSCT patients, and radiologists should be familiar with the subtle features that may help to differentiate these disease entities. The focus of this article is on the diagnosis of fungal pneumonia in HSCT patients with an emphasis on radiologists’ roles in establishing the diagnosis of fungal pneumonia and the guidance of clinical management.

National trends in incidence, prevalence and disability-adjusted life years of invasive aspergillosis in Iran: a systematic review and meta-analysis

Objectives: We aimed to study the epidemiology, prevalence, incidence, clinical manifestations, underlying diseases, treatments, outcomes, and societal impact through disability-adjusted life years (DALYs) of IA in Iran. Methods: A random-effect meta-analytic model was fitted to estimate the prevalence and incidence of IA in Iran. We also calculated DALYs. Results: Out of 79 published studies during the past 25 years from Iran, 23 met the inclusion criteria. A total of 2947 patients were included, of whom 396 (13.4%) patients were diagnosed with IA according to EORTC/MSG and ICU criteria. The main underlying condition for IA was hematologic disorders (39.4%). A. flavus 86 (43%) was the most common isolate. The pooled prevalence and incidence rates were 20.5 (95% CI 12.5 to 29.9) and 4.8 (95% CI 2.3-8.2) per 100,000 population, respectively. Total DALYs was estimated 164.13 per 100,000 population. YLLs constitute the majority of IA burden compared to YLDs (162.80 YLLs/100,000 population vs 1.33 YLDs per 100,000 population). The highest YLL rates were found in people aged 45-49 (62.9 YLLs/100,000 population) and 30-34 years (45.2 YLLs/100,000 population), respectively. Conclusion: This study indicates an increasing burden of IA in Iran, despite the extensive use of prophylaxis, challenging the public health, especially immunocompromised patients.

Combination antifungal treatment for invasive fungal disease after hematopoietic stem cell transplantation in children with hematological disorders

BACKGROUND

Invasive fungal disease (IFD) has a poor prognosis in children with hematological disorders after hematopoietic stem cell transplantation (HSCT). We assessed if drug combinations with different targets may improve the outcome.

METHODS

Retrospective study to assess the outcome of combination antifungal therapy (CAT) for proven-probable IFD (PP-IFD) in children with hematological disorders after HSCT from January 2008 to June 2018.

RESULTS

Over the 10-year period, 95 PP-IFD were diagnosed in pediatric recipients, median age of 5.6 years. Twenty-seven patients received combinations of caspofungin and voriconazole, 28 patients received combinations of caspofungin and amphotericin B, and 40 patients received combinations of voriconazole and amphotericin B. The overall response rate of PP-IFD was 77.9%, while the 100-day overall survival rates were 66.8%. Univariate analysis showed that factors that significantly affected the response to combination treatments were type of combination (P = 0.02), the stem cell source (P = 0.04), the donor type (P = 0.03), HLA-match (P = 0.03), aGVHD (P = 0.02), period of treatment (P = 0.044), use of corticosteroids (0.036), CD4:CD8 ratio (P = 0.014), and CMV viremia (P = 0.033). In addition, multivariate analysis demonstrated that only the type of combination remained a significant factor (odds ratio = 0.335, 95% confidence interval: 0.071-0.812, P = 0.042). Forty-three children suffered from mild and reversible adverse reactions, no serious side effects during treatment.

CONCLUSION

A variety of factors can affect the outcome of CAT. Combination of caspofungin with voriconazole is a safe and helpful treatment option for HSCT recipients with IFD.

Respiratory failure in the hematopoietic stem cell transplant recipient

The number of patients receiving hematopoietic stem cell transplantation (HSCT) is rapidly rising worldwide. Despite substantial improvements in peri-transplant care, pulmonary complications resulting in respiratory failure remain a major contributor to morbidity and mortality in the post-transplant period, and represent a major barrier to the overall success of HSCT. Infectious complications include pneumonia due to bacteria, viruses, and fungi, and most commonly occur during neutropenia in the early post-transplant period. Non-infectious complications include idiopathic pneumonia syndrome, peri-engraftment respiratory distress syndrome, diffuse alveolar hemorrhage, pulmonary veno-occlusive disease, delayed pulmonary toxicity syndrome, cryptogenic organizing pneumonia, bronchiolitis obliterans syndrome, and post-transplant lymphoproliferative disorder. These complications have distinct clinical features and risk factors, occur at differing times following transplant, and contribute to morbidity and mortality.

Fungal infections in hematopoietic stem cell transplantation in children at a pediatric children's hospital in Argentina

Our primary objective was to describe the incidence of proven or probable invasive fungal infections (IFIs), a devastating complication of hematopoietic stem cell transplant (HSCT), in HCST in a middle-income country. Secondary objectives were to describe factors associated with IFIs and outcomes. In this single center retrospective study, pediatric patients who underwent a first allogeneic or autologous HSCT from 1998 to 2016 were included. Of the 251 HSCT recipients: 143 transplants were allogeneic and 108 were autologous. Overall, 23 (9%) experienced an IFI, mostly due to yeasts (83%). IFIs were more common in allogeneic HSCT (18/143, 13%) than in autologous HSCT (5/108, 5%; P = .045). Of the 23 patients with IFIs, 14 (61%) died, but only 1 directly from IFI (pulmonary aspergillosis). Overall survival at 3 years was 0.42 ± 0.11 in patients with IFIs and 0.60 ± 0.37 in those without IFIs (P = .049). In Argentina, IFIs during HSCT are common. Recipients of allogeneic HSCT are at higher risk, and IFI is associated with reduced overall survival. Future work should focus on interventions to reduce and improve IFI outcomes in children undergoing transplants in low- and middle-income countries.

Diagnostic Values and Limitations of (1,3)-β-D-Glucans and Galactomannan Assays for Invasive Fungal Infection in Patients Admitted to Pediatric Intensive Care Unit

The relationship among (1,3)-β-D-glucans (BG), galactomannan (GM), and the risk of developing invasive fungal infections (IFI) has been observed in adult ICU and in children with hematological malignancies. Only scant data evaluated the value of BG/GM assays for diagnosis of IFI in patients with nonhematological diseases in pediatric intensive care unit (PICU). In this study, we assessed the diagnostic value of these markers for IFI in PICU. The records of 230 patients were retrospectively evaluated. Out of 117 patients (7 proven, 23 probable, and 87 cases without evidence of IFI) performed GM and BG assays. The results showed many factors were associated with false-positive test results. Patients who aged over 3 years had higher levels of GM and BG than younger infants. The levels of BG were higher in subjects with dairy, human blood products, antibiotics, and corticosteroids therapy than in cases without these treatments. Unlike BG assay, GM assay was less susceptible to above-mentioned factors expect blood products. The levels of BG and GM in IFI cases were dramatically higher than in controls. The diagnostic performance of these assays showed that GM assay had better results when compared with BG assay. On the whole, negative predictive value in both GM and BG assays was dramatically higher than other diagnostic parameters. In conclusion, BG assay was highly susceptible to many factors, and GM assay could be useful for diagnosis of IFI for its high sensitivity, but the over benefit of this assay limited in its inadequate specificity. The comparative advantage of BG and BG assays lied in excluding IFI in non-hematological PICU patients.

Surgery for localized pulmonary mycotic infections in patients with hematopoietic disorder

Background

Surgical resection is considered to be the most effective treatment for localized pulmonary mycotic infections. However it is also a particularly challenging procedure because it is associated with considerable mortality and morbidity. Furthermore, hematopoietic disorders usually cause immunosuppression, anemia, and coagulopathy, which are definite risk factors for surgery. The purpose of this study is to evaluate the surgical outcomes of pulmonary mycotic infections in hematopoietic disorder patients.

Methods

Between 2011 and 2013, 23 patients underwent surgical treatment for pulmonary mycotic infections at a single institution. The patients were divided into two groups; Group A (hematopoietic disorder patients, n = 9) and Group B (n = 14). We retrospectively reviewed medical and radiologic data.

Results

The complex type was more frequent in group A (66.6 %) than in group B (35.7 %). Postoperatively, there was no mortality. However, morbidity was 22.2 % (2 incomplete expansion) in group A, and 35.6 % (1 prolonged air leak, 3 bleeding, 1 Bronchopleural fistula) in group B. The difference in morbidity between the groups did not show any statistical significance (p = 0.657) as well as duration of chest tube drainage, and postoperative hospital stay. The hematopoietic disorder patients did not impose a risk factor for morbidity and mortality.

Conclusions

Although hematopoietic disorder patients have many surgical risk factors, the surgical treatment of pulmonary mycotic infections produces very acceptable outcomes in selected cases.

Histone-modifying enzymes, histone modifications and histone chaperones in nucleosome assembly: Lessons learned from Rtt109 histone acetyltransferases

During DNA replication, nucleosomes ahead of replication forks are disassembled to accommodate replication machinery. Following DNA replication, nucleosomes are then reassembled onto replicated DNA using both parental and newly synthesized histones. This process, termed DNA replication-coupled nucleosome assembly (RCNA), is critical for maintaining genome integrity and for the propagation of epigenetic information, dysfunctions of which have been implicated in cancers and aging. In recent years, it has been shown that RCNA is carefully orchestrated by a series of histone modifications, histone chaperones and histone-modifying enzymes. Interestingly, many features of RCNA are also found in processes involving DNA replication-independent nucleosome assembly like histone exchange and gene transcription. In yeast, histone H3 lysine K56 acetylation (H3K56ac) is found in newly synthesized histone H3 and is critical for proper nucleosome assembly and for maintaining genomic stability. The histone acetyltransferase (HAT) regulator of Ty1 transposition 109 (Rtt109) is the sole enzyme responsible for H3K56ac in yeast. Much research has centered on this particular histone modification and histone-modifying enzyme. This Critical Review summarizes much of our current understanding of nucleosome assembly and highlights many important insights learned from studying Rtt109 HATs in fungi. We highlight some seminal features in nucleosome assembly conserved in mammalian systems and describe some of the lingering questions in the field. Further studying fungal and mammalian chromatin assembly may have important public health implications, including deeper understandings of human cancers and aging as well as the pursuit of novel anti-fungal therapies.

Proteomic demonstration of the recurrent presence of inter-alpha-inhibitor H4 heavy-chain during aspergillosis induced in an animal model

Invasive pulmonary aspergillosis remains a matter of great concern in oncology/haematology, intensive care units and organ transplantation departments. Despite the availability of various diagnostic tools with attractive features, new markers of infection are required for better medical care. We therefore looked for potential pulmonary biomarkers of aspergillosis, by carrying out two-dimensional (2D) gel electrophoresis comparing the proteomes of bronchial-alveolar lavage fluids (BALF) from infected rats and from control rats presenting non-specific inflammation, both immunocompromised. A bioinformatic analysis of the 2D-maps revealed significant differences in the abundance of 20 protein spots (ANOVA P-value<0.01; q-value<0.03; power>0.8). One of these proteins, identified by mass spectrometry, was considered of potential interest: inter-alpha-inhibitor H4 heavy-chain (ITIH4), characterised for the first time in this infectious context. Western blotting confirmed its overabundance in all infected BALF, particularly at early stages of murine aspergillosis. Further investigations were carried on rat serum, and confirmed that ITIH4 levels increased during experimental aspergillosis. Preliminary results in human samples strengthened this trend. To our knowledge, this is the first description of the involvement of ITIH4 in aspergillosis.