A Prospective Viral Monitoring Study After Pediatric Allogeneic Hematopoietic Stem Cell Transplantation for Malignant and Nonmalignant Diseases

Monitoring of adenoviremia in pediatric patients undergoing hematopoietic stem cell transplantation: Is it alone sufficient to predict adenoviral disease?

BACKGROUND

We aimed to evaluate our pediatric HSCT recipients routinely monitored for adenoviremia and to determine the adequacy of this monitoring in predicting adenoviral disease (AD).

METHODS

A retrospective cohort of patients who underwent allogeneic HSCT between January 2021 and August 2022, and routinely monitored for adenoviremia by real-time PCR was included in our survey. Demographic and clinical data of the patients were recorded. Incidence rates, risk factors, and mortality rates related to adenoviremia, and AD were analyzed.

RESULTS

Among 104 HSCTs performed in 94 patients adenovirus (AdV) was revealed in 27 (26%) episodes and adenoviremia in 18 (17.3%) HSCT episodes. AD without adenoviremia developed in nine episodes (8.6%). Disseminated disease was significantly more frequently detected in episodes with adenoviremia (p = .008). GVHD was independent risk factor for AdV detection (OR: 8.6, 95% CI: 2.03-33.7, p = .001). Viremia developed within a shorter time interval after HSCT in isolated episodes of adenoviremia compared to those with concomitant AD (p = .006). Initial and peak viral loads were significantly higher in adenoviremia with AD (p < .001). Mortality was higher in the AdV-detected episodes (p < .001) than in the AdV-undetected episodes. AdV-related mortality was found to be 22.2%. Adenoviremia increased the risk of mortality (OR: 1.2, 95% CI: 0.22-1.33, p = .01).

CONCLUSIONS

Adenoviremia monitoring is an important process in the detection of AD. Since some patients may develop AD without accompanying by adenoviremia, monitoring for AdV in blood samples should be supported with other monitoring methods in order to evaluate the probable involvement of different organs or systems.

Clinical and immune features of human parvovirus B19 infection in allogeneic stem cell transplantation recipients: A retrospective monocentric study

BACKGROUND

Human parvovirus B19 (B19V) infection is associated with pure red cell aplasia (PRCA) in immunocompromised patients; however, the spectrum of manifestations associated with B19V in allogeneic hematopoietic stem cell transplantation recipients (alloHSCT) has rarely been reported.

METHODS

In this study, we aimed to report clinical and immune features of B19V infection after alloHSCT. We retrospectively collected and analyzed clinical and microbiological data of all transplanted patients with B19V DNAmia or tissue infection detected by polymerase chain reaction (PCR) in our center from 2010 to 2021.

RESULTS

We report 35 cases of B19V infections in 33 patients. Median time from transplant to B19V first PCR positivity was 6.9 months (interquartile range (IQR) [1.6-18.9]). No preferential immune profile, type of transplantation or conditioning was identified. Hematological impairment was the most frequent sign, followed by rash and fever. Unconventional clinical forms were also detected, such as acute myelitis and myositis. For some cases, the direct relationship between symptoms and B19V infection was difficult to prove but was suggested by targeted tissue PCR positivity. When hematological impairment was not at the forefront, reticulocytopenia helped to diagnose B19V infections. Treatment was mainly based on high dose intravenous immunoglobulin.

CONCLUSION

Although hematological impairment was the most frequent sign, B19V can affect multiple targets and lead to atypical manifestations. Because of its heterogeneous clinical presentation, B19V infection is likely under-diagnosed. Diagnosis of unusual B19V organ involvement needs combination of arguments which can include targeted tissue PCR.

Droplet digital PCR development for adenovirus load monitoring in children after hematopoietic stem cell transplantation

Human adenovirus (AdV) reactivation after hematopoietic stem cell transplantation (HSCT) is associated with life-threatening clinical manifestations. Real-time quantitative PCR (qPCR) has been widely used to measure AdV loads. However, qPCR has not been standardized for AdV. Droplet digital polymerase chain reaction (ddPCR) enables the absolute quantification of viral loads that is a novel pathogen detection technology. DdPCR would enable a more accurate AdV DNA detection compared to qPCR. In this study, ddPCR was developed for AdV DNA and compared its performance characteristics with qPCR. Then, AdV DNAemia incidence during the first 12 weeks after allogenic HSCT was retrospectively examined by qPCR and ddPCR in 97 HSCT episodes using the preserved 545 DNA samples. DdPCR showed better reproducibility and sensitivity, as well as equivalent quantifiability compared to qPCR. AdV DNA among HSCT patients was detected in 11 (2.0%) and 49 (9.0%) of 545 samples by qPCR and ddPCR, respectively. AdV DNA levels of >1000 copies/mL were observed in five cases by qPCR and/or ddPCR. However, two developed fulminant hepatitis and died, while other patients remained asymptomatic with subsequently undetectable AdV DNA. In conclusion, ddPCR was more sensitive and reproducible in detecting AdV DNA among pediatric HSCT recipients than qPCR. DdPCR represents the potential to provide a more accurate DNAemia detection, determine cutoff values for treatment initiation, and antiviral efficacy assessment.

Pediatric Infectious Diseases Related to Transplantation: Insights From Japan

Infectious diseases after transplantation account for significant morbidity and mortality in children undergoing transplantation; the importance of pediatric transplant infectious disease (TID) specialists has therefore been recognized. Although tremendous advancement continues in transplantation medicine, pediatric-specific data and evidence are limited. In Japan, the majority of TIDs had not been managed by infectious disease specialists because pediatric infectious diseases have not been recognized as a solo subspecialty until recently in Japan. However, in the last decade, there was a new movement for pediatric TID in Japan; some pediatric infectious disease specialists trained outside Japan have been playing an important role in managing pediatric TID in a few academic and pediatric institutions. In this review article, we introduce the current status of infectious complications related to pediatric hematopoietic cell and solid organ transplantation, highlighting currently available local evidence, common practice and issues in the field of pediatric TID in Japan.

The Impact of High CMV Viral Load and Refractory CMV Infection on Pediatric HSCT Recipients with Underlying Non-Malignant Disorder

Hematopoietic stem cell transplantation (HSCT) is a curative therapy for an increasing number of nonmalignant indications. Its use is restricted by severe transplant-related complications, including CMV infection; despite various prophylactic and therapeutic strategies, CMV reactivation has remarkable morbidity and mortality. The analysis included 94 children with nonmalignant disorder who underwent allogeneic HSCT in the Department of Pediatric Hematology, Oncology, and Bone Marrow Transplantation in Wrocław during years 2016–2020. Twenty-seven (29%) children presented with CMV infection, including ten (10/27; 37%) with high level CMV viremia (10,000 copies/mL). Six patients experienced subsequent CMV reactivation. The first-line ganciclovir-based (GCV) treatment was insufficient in 40% (11/27) of children. Overall survival (OS) was significantly lower in children with high CMV viremia compared to those with low levels/no CMV [1yrOS High CMV = 0.80 (95% CI 0.41–0.95) vs. 1yrOS others = 0.96 (95% CI 0.89–0.99)]. Similarly, patients with resistant and recurrent infections had greater risk of death. CMV reactivation at any level relevantly prolonged the hospital stay. CMV reactivation with high viremia load and resistant/recurrent CMV infections lead to a significant decrease in OS in children with nonmalignant disorders treated with HSCT. Our data proves there is an urgent need to introduce an effective anti-CMV prophylaxis in this cohort of patients.