Opportunistic infections and deaths are less common among HIV-infected youth in the US in the cART era, but the mortality rate remains elevated. Deaths were associated with poor HIV control and older age. Emerging complications, such as psychiatric, inflammatory, metabolic, and genital tract diseases, need to be addressed.
This paper reviews recent advances in three selected areas of pediatric invasive candidiasis: epidemiology, diagnosis, and treatment. Although the epidemiological trends of pediatric invasive candidiasis illustrate a declining incidence, this infection still carries a heavy burden of mortality and morbidity that warrants a high index of clinical suspicion, the need for rapid diagnostic systems, and the early initiation of antifungal therapy. The development of non-culture-based technologies, such as the T2Candida system and (1→3)-β-d-glucan detection assay, offers the potential for early laboratory detection of candidemia and CNS candidiasis, respectively. Among the complications of disseminated candidiasis in infants and children, hematogenous disseminated Candida meningoencephalitis (HCME) is an important cause of neurological morbidity. Detection of (1→3)-β-d-glucan in cerebrospinal fluid serves as an early diagnostic indicator and an important biomarker of therapeutic response. The recently reported pharmacokinetic data of liposomal amphotericin B in children demonstrate dose–exposure relationships similar to those in adults. The recently completed randomized clinical trial of micafungin versus deoxycholate amphotericin B in the treatment of neonatal candidemia provides further safety data for an echinocandin in this clinical setting.
These data, as well as data from previous California studies, suggest updated strategies for the management of severe pertussis. These include perform serial white blood cell counts, treat all presumptive cases with azithromycin, evaluate for pulmonary hypertension, intubate and administer oxygen for apneic episodes and administer inotropic/vasoactive agents for cardiogenic shock. Do not administer steroids or nitric oxide. Criteria for exchange blood transfusion therapy for leukocytosis with lymphocytosis are suggested.
Conversion from IIV to CIV therapy in selected pediatric patients appeared to be safe and well tolerated, with few adverse effects noted. Using the institutional CIV dosing guideline, goal plateau SVC values were attained in most patients within 24-48 hours.
Transgenic expression constructs were employed to identify a cis-acting transcription element in the T cell receptor (TCR)-γ locus, called HsA, between the Vγ5 and Vγ2 genes. In constructs lacking the previously defined enhancer (3′ECγ1), HsA supports transcription in mature but not immature T cells in a largely position-independent fashion. 3′ECγ1, without HsA, supports transcription in immature and mature T cells but is subject to severe position effects. Together, the two elements support expression in immature and mature T cells in a copy number–dependent, position-independent fashion. Furthermore, HsA was necessary for consistent rearrangement of transgenic recombination substrates. These data suggest that HsA provides chromatin-opening activity and, together with 3′ECγ1, constitutes a T cell–specific locus control region for the TCR-γ locus.
Background
Trichosporon species are uncommon but emerging pathogens that cause life-threatening infections that are resistant to amphotericin B and echinocandins. Diagnosis of deeply invasive trichosporonosis is often elusive to conventional culture methods until locally advanced or disseminated disease has advanced.
CT scans Pulmonary Trichosporonosis
Lung Bx of Trichosporon detected by Karius Cell-Free DNA Metagenomic Assay of Plasma
Methods
Review of cases of next-generation sequencing of microbial cell-free DNA from plasma using the Karius-based technology for establishing a diagnosis of invasive trichosporonosis
Results
We found that next-generation sequencing of microbial cell-free DNA from plasma using the Karius-based technology established a diagnosis in six pediatric and adult patients. The median age was 17 yrs (8-72 yrs) all patients had underlying acute leukemia myelogenous leukemia. Six patients had pulmonary nodules and two also had multiple cutaneous lesions with negative blood cultures. Biopsies of one pulmonary nodule and of two cutaneous lesions revealed yeast-like cells. Culture of cutaneous lesions in two patients grew Trichosporon sp. Karius assays performed on plasma and analyzed against a database of more than 300 species of fungi identified Trichosporon asahii in two cases, Trichosporon spp. in three, Trichosporon faecale in one. In all cases, the metagenomic results defined therapy for treatment of invasive trichosporonosis, which is based in antifungal triazoles. In one patient with pulmonary nodules, lung biopsy revealed mixed septate and non-septate hyphal elements that later grew Trichosporon asahii, Rhizomucor pusillus, and Candida parapsilosis, all of which were identified by Karius assay.
Conclusion
Invasive Trichosporon spp. are uncommon polyene and triazole-resistant pathogens that cause life-threatening invasive fungal disease resistant in immunocompromised patient with hematological malignancies; next-generation sequencing of fungal cell-free DNA by Karius-based technology identified all six cases of pulmonary and disseminated trichosporonosis, contributing to early detection and pathogen-directed antifungal therapy.
Disclosures
Asim A. Ahmed, MD, Karius (Employee) Joshua Wolf, MBBS, PhD, FRACP, Karius inc (Grant/Research Support)
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.