CRISPR/Cas9 genome editing of CCR5 combined with C46 HIV-1 fusion inhibitor for cellular resistant to R5 and X4 tropic HIV-1.

Hematopoietic stem-cell (HSC) transplantation using a donor with a homozygous mutation in the HIV co-receptor CCR5 (CCR5Δ32/Δ32) holds great promise as a cure for HIV-1. Previously, there were three patients that had been reported to be completely cured from HIV infection by this approach. However, finding a naturally suitable Human Leukocyte Antigen (HLA)-matched homozygous CCR5Δ32 donor is very difficult. The prevalence of this allele is only 1% in the Caucasian population. Therefore, additional sources of CCR5Δ32/Δ32 HSCs are required. The Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR-associated (Cas) system is one method to mediate CCR5 knockout in HSCs that has been successfully employed as a gene editing tool in clinical trials. Additional anti-HIV-1 strategies are still required for broad-spectrum inhibition of HIV-1 replication. Here in this study, we combined an additional anti-HIV-1 therapy, which is C46, a cell membrane-anchored HIV-1 fusion inhibitor with the CRISPR/Cas9 mediated knockout CCR5. The combined HIV-1 therapeutic genes were investigated for the potential prevention of both CCR5 (R5)- and CXCR4 (X4)-tropic HIV-1 infections in the MT4CCR5 cell line. The combinatorial CRISPR/Cas9 therapies were superior compared to single method therapy for achieving the HIV-1 cure strategy and shows potential for future applications.

Severe acute respiratory syndrome coronavirus 2 infection rate among pediatric patients with respiratory symptoms.

BACKGROUND: The incidence of coronavirus disease 2019 (COVID-19) in children has been increasing worldwide since the onset of the pandemic. This study examined the risk factors and characteristics of COVID-19 among pediatric patients compared to other respiratory viral infections. METHODS: This was a prospective cross-sectional study. Patients aged 0-18 years presenting with respiratory symptoms from October 2020 to December 2021 were included. Demographic and clinical data were reviewed. RESULTS: In total, 738 pediatric patients were enrolled. Of these, 48.5% had COVID-19, and 41.3% were infected with another respiratory virus. The COVID-19 incidence increased from 0.5% during the original strain outbreak (October 2020 to March 2021) to 56.5% and 73.4% during the alpha (April to June 2021) and delta (July to December 2021) periods, respectively. Children aged 6-18 years, being female, obesity, exposure to household members with COVID-19, and the delta period were risk factors for COVID-19. Being aged 1-5 years, obesity, shortness of breath, productive cough, and chest pain were associated with COVID-19 pneumonia. Children aged 5-18 years, underlying neurological disease, a history of COVID-19 pneumonia, and the delta period were associated with long COVID. CONCLUSIONS: Pediatric COVID-19 patients presenting with respiratory symptoms who are obese or have been exposed to household members with COVID-19 should be tested for COVID-19. COVID-19 patients who are obese, younger than five years old, or who present with shortness of breath, productive cough, or chest pain should be evaluated for pneumonia. COVID-19 patients with a history of COVID-19 pneumonia or underlying neurological disease should receive follow-up for long COVID.

Immune reconstitution in children after haploidentical haematopoietic stem cell transplantation.

INTRODUCTION: Immune reconstitution (IR) kinetics of paediatric patients underwent haploidentical haematopoietic stem cell transplantation (HSCT) with post-transplant cyclophosphamide (PTCy) have not been extensively studied. We compared IR patterns of children receiving HSCT from haploidentical (n = 92) and HLA-matched donors (n = 36), and analysed risk factors for viral infection in these patients. METHODS: We prospectively measured lymphocyte subset numbers before HSCT and at 1, 3, 6 and 12 months after HSCT. Blood cytomegalovirus (CMV), Epstein-Barr virus, adenovirus, BK virus (BKV) and urine adenovirus and BKV viral loads were measured at designated time points. RESULTS: The median numbers of total T and T helper cells at 1 month were significantly lower in the haploidentical group compared with the HLA-matched group. Haploidentical HSCT recipients had significantly lower median numbers of several T cell subsets and B cells for 1 year after HSCT. The median NK cell count of the haploidentical group was lower at 1 month. BKV haemorrhagic cystitis, blood CMV and urine adenovirus reactivation were more frequently found in the haploidentical group. Post-haploidentical HSCT patients receiving anti-T lymphocyte globulin (ATG) had significantly lower median numbers of total T cells (at 1 month) and T helper cells (at 6 and 12 months) and higher rate of blood BKV reactivation compared with those without ATG. CONCLUSION: Paediatric patients who undergo haploidentical HSCT with PTCy are likely to have delayed IR and an increased risk of viral reactivation/infection compared with HLA-matched HSCT. The addition of ATG to PTCy delayed T cell recovery and increased risk of BKV reactivation.

HIV-1 proviral DNA in purified peripheral blood CD34+ stem and progenitor cells in individuals with long-term HAART; paving the way to HIV gene therapy.

Human immunodeficiency virus (HIV)-1 infection is an important public health problem worldwide. After primary HIV-1 infection, transcribed HIV-1 DNA is integrated into the host genome, serving as a reservoir of the virus and hindering a definite cure. Although highly active antiretroviral therapy suppresses active viral replication, resulting in undetectable levels of HIV RNA in the blood, a viral rebound can be detected after a few weeks of treatment interruption. This supports the concept that there is a stable HIV-1 reservoir in people living with HIV-1. Recently, a few individuals with HIV infection were reported to be probably cured by hematopoietic stem transplantation (HSCT). The underlying mechanism for this success involved transfusion of uninfected hematopoietic stem and progenitor cells (HSPCs) from CCR5-mutated donors who were naturally resistant to HIV infection. Thus, gene editing technology to provide HIV-resistant HSPC has promise in the treatment of HIV infections by HSCT. In this study, we aimed to find HIV-infected individuals likely to achieve a definite cure via gene editing HSCT. We screened for total HIV proviral DNA by Alu PCR in peripheral blood mononuclear cells (PBMCs) of 20 HIV-infected individuals with prolonged viral suppression. We assessed the amount of intact proviral DNA via a modified intact proviral DNA assay (IPDA) in purified peripheral CD34+ HSPCs. PBMCs from all 20 individuals were positive for the gag gene in Alu PCR, and peripheral CD34+ HSPCs were IPDA-negative for six individuals. Our results suggested that these six HIV-infected individuals could be candidates for further studies into the ability of gene editing HSCT to lead to a definite HIV cure.

Cytomegalovirus-Specific T Cells in Pediatric Liver Transplant Recipients.

Cytomegalovirus (CMV) infection is a major opportunistic infection after liver transplantation (LT) that necessitates monitoring. Because of the lack of studies in children, we aimed to investigate CMV-specific T cell immune reconstitution among pediatric LT recipients. The recipients were monitored for CMV infection and CMV-specific T cells from the start of immunosuppressive therapy until 48 weeks after LT. Clinically significant CMV viremia (csCMV) requiring preemptive therapy was defined as a CMV load of >2000 IU/mL. Peripheral blood CMV-specific T cells were analyzed by flow cytometry based on IFNγ secretion upon stimulation with CMV antigens including immediate early protein 1 (IE1) Ag, phosphoprotein 65 (pp65) Ag, and whole CMV lysate (wCMV). Of the 41 patients who underwent LT, 20 (48.8%) had csCMV. Most (17/20 patients) were asymptomatic and characterized as experiencing CMV reactivation. The onset of csCMV occurred approximately 7 weeks after LT (interquartile range: 4-12.9); csCMV rarely recurred after preemptive therapy. Lower pp65-specific CD8+ T cell response was associated with the occurrence of csCMV (p = 0.01) and correlated with increased viral load at the time of csCMV diagnosis (ρ = -0.553, p = 0.02). Moreover, those with csCMV had lower percentages of IE1-specific CD4+ and wCMV-reactive CD4+ T cells at 12 weeks after LT (p = 0.03 and p = 0.01, respectively). Despite intense immunosuppressive therapy, CMV-specific T cell immune reconstitution occurred in pediatric patients post-LT, which could confer protection against CMV reactivation.

Clinical and immunological characteristics for BK polyomavirus-associated nephropathy after kidney transplantation.

INTRODUCTION: BK polyomavirus (BKPyV)-associated nephropathy (BKPyVAN) can cause a significant risk of allograft impairment after kidney transplantation (KT). Intact BKPyV-specific immunity is associated with viral containment. This study investigated BKPyV-specific immunological factors among KT recipients. METHODS: This prospective study in a single transplant center from January 2019 to August 2019 assessed associations between clinical and immunological characteristics, with a focus on BKPyV-cell-specific immunity and BKPyVAN, among KT recipients aged ≥15 years. The numbers of interferon-gamma (IFN-γ)-producing CD4+  T, CD8+  T, natural killer (NK), and natural killer T (NKT) cells were measured after stimulation with large T antigen and viral capsid protein 1 (VP1). RESULTS: In total, 100 KT recipients were included (mean age ± SD, 42 ± 11 years); 35% of the recipients were female patients, and 70% had received induction immunosuppressive therapy. The 1-year cumulative incidence of high-level BKPyV DNAuria (possible BKPyVAN) and (presumptive BKPyVAN) was 18%. Among 40 patients with immunological factor data, pre-KT %NK cells (hazard ratio [HR], 1.258; 95% confidence interval [CI], 1.077-1.469; p = .004) and %VP1-specific NK cells (HR, 1.209; 95% CI, 1.055-1.386; p = .006) were factors independently associated with possible and presumptive BKPyVAN. KT recipients with possible and presumptive BKPyVAN were more likely to exhibit significant mean coefficients of %NK, %VP1-specific NK, and %NKT cells at 1 month after KT than before KT (all p < .05). CONCLUSION: Individuals with nonspecific and VP1-specific NK cells before KT and increasing numbers of these cells after KT may be at risk for high-level BKPyV DNAuria and presumptive BKPyVAN. Further studies are needed to determine the utility of BKPyV-specific innate immune surveillance in predicting the occurrence of BKPyVAN.

Risk factors of cytomegalovirus infection after pediatric liver transplantation and effectiveness of preemptive therapy.

BACKGROUND: Cytomegalovirus (CMV) infection is the most common infection following pediatric liver transplantation (LT). Preemptive therapy (PET) is an approach to initiate antiviral treatment for asymptomatic early CMV viremia detected by surveillance testing. However, data on CMV infection after PET are scarce, and the optimal cut-off remains controversial. This study aimed to evaluate the incidence, risk factors, and consequences of CMV infection in pediatric LT using 2 different viral load (VL) cut-offs. METHODS: We retrospectively reviewed patients aged 0-18 years who underwent LT at Ramathibodi Hospital between March 2001 and August 2020. Demographic data, CMV infection, CMV treatment, and consequences of CMV infection were collected. CMV viremia was monitored by a quantitative nucleic acid amplification test. Clinical outcomes were compared after starting antiviral therapy at a low (>400 but <2000 IU/mL) and a high VL cut-off (≥2000 IU/mL). RESULTS: A total of 126 patients were included. CMV infection was 71% (90/126), with an incidence rate of 5.5 per 1000 patient-day. Higher tacrolimus and prednisolone dosages were associated with CMV infection with an adjusted hazard ratio of 1.2 (95%CI 1.0-1.4, p = .02) and 2.4 (95%CI 1.9-3.4, p < .001), respectively. The consequences of CMV infection did not differ significantly for the low and high CMV VL cut-off groups. CONCLUSION: CMV infection in LT recipients is common and is associated with higher tacrolimus and corticosteroid dosage. Additionally, using the CMV VL cut-off at 2000 IU/mL to initiate antiviral therapy is practical and effective in preventing CMV disease.

Immunogenicity of Hepatitis B Vaccine in Pediatric Systemic Lupus Erythematosus Patients.

BACKGROUND: Pediatric patients with systemic lupus erythematosus (SLE) are at increased infectious risk caused by underlying immunologic dysregulation and immunosuppressive therapy. Hepatitis B virus (HBV) could be reactivated during the immunosuppressive treatment in patients with past HBV infections. Information on immunogenicity after hepatitis B (HB) immunization and reimmunization are still scarce. METHODS: SLE patients 5-18 years of age who had completed a primary HB immunization were enrolled. Anti-HBs levels at enrollment and after each vaccine dose were determined. Patients with anti-HBs levels < 10 mIU/mL were administered 1 booster dose. After 1 booster dose, patients with negative anti-HBs levels were administered 2 more booster doses. RESULTS: Ninety-three SLE patients were enrolled. The prevalence of seroprotection assessed by anti-HBs > 10 mIU/mL after completion of a primary HB immunization was 25.8% (95% CI: 17.2-34.4). Lupus nephritis was associated with unprotective anti-HBs levels [odds ratio (OR): 4.341; 95% CI: 1.044-18.040]. The anti-HBs seroconversion was 72.3% (95% CI: 61.5-83.0) after 1 booster dose and increased up to 93.4% (95% CI: 86.9-98.4) after 3 booster doses. SLE Disease Activity Index-2000 score ≥ 4 (OR: 4.625; 95% CI: 1.45-14.80) was significantly associated with nonseroconversion after the first booster dose. Hypocomplementemia before the first and second booster doses (OR: 27; 95% CI: 1.26-578.35) was significantly associated with nonseroconversion after 3 booster doses. CONCLUSIONS: All pediatric SLE patients should be evaluated for HBV serological status before immunosuppressive treatment. SLE patients with SLE Disease Activity Index-2000 score > 4 should need 3 booster doses if their anti-HBs level was < 10 mIU/mL.

Association of zinc deficiency with infectious complications in pediatric hematopoietic stem cell transplantation patients.

BACKGROUND: Zinc plays essential roles in immune function and epithelial integrity. Patients undergoing hematopoietic stem cell transplantation (HSCT) often have low plasma zinc levels because of poor intake and diarrhea. We hypothesized that patients with zinc deficiency before HSCT had worse infectious complications after HSCT compared with patients with normal zinc levels. Citrulline, a marker of intestinal integrity, was also hypothesized to be lower in patients with zinc deficiency. PATIENTS AND METHODS: Thirty patients undergoing HSCT at Ramathibodi Hospital during March 2020-September 2021 were enrolled. Blood samples for plasma zinc and citrulline were collected during the HSCT period. The 14- and 90-day outcomes after HSCT were prospectively recorded. RESULTS: Twelve of 30 (40%) patients had zinc deficiency before HSCT. Zinc-deficient patients were younger (median (interquartile range): 6 (8.8) vs 13 (5.8) years old; p = 0.017). Zinc levels tended to increase after admission in both groups. Patients with zinc deficiency had lower citrulline levels than those with normal zinc levels. Citrulline levels decreased in both groups after stem cell infusion, and the level was not significantly different between the two groups. Zinc-deficient patients had a higher rate of bacterial infection within 90 days after HSCT than those with normal zinc levels (6 in 12 patients (50.0%) vs 1 in 18 patients (5.6%); odds ratio [OR]: 17.0; 95% confidence interval [CI]: 1.68-171.70; p = 0.016). This remained significant after adjustments for age (adjusted OR: 12.31; 95% CI: 1.084-139.92; p = 0.043). CONCLUSION: The prevalence of zinc deficiency in pediatric patients undergoing HSCT was high. Zinc-deficient patients had lower citrulline levels and higher incidence of bacterial infection after HSCT. However, citrulline level was not different between patients with and without bacterial infections. It is worth to investigate whether zinc supplementation before HSCT can reduce bacterial infection after HSCT.

Pediatric drug utilization evaluation of cefepime and piperacillin/tazobactam.

BACKGROUND: Drug utilization evaluation (DUE) is a systematic, criteria-based assessment of medicine that aims to optimize the appropriateness of antibiotic prescription. This study aimed to evaluate the performance of the DUE on prescriptions of two commonly used antibiotics in a pediatric population, cefepime and piperacillin/tazobactam, in a tertiary care hospital. METHODS: This quasi-experimental study was conducted at the Department of Pediatrics, Ramathibodi Hospital, between March 2020 and August 2021. All hospitalized children aged 1 month to 20 years who received at least one dose of cefepime or piperacillin/tazobactam were enrolled. Before implementing the DUE, cefepime and piperacillin/tazobactam prescriptions were retrospectively evaluated using the DUE criteria. During the 6 month DUE implementation period, physicians voluntarily chose to use DUE to assess the prescriptions' appropriateness. Demographic data, antibiotic use, and clinical data were recorded. RESULTS: There were 304 prescriptions of cefepime and piperacillin/tazobactam, with 108 empirical prescriptions (72 patients) in the DUE group and 158 prescriptions (138 patients) in the non-DUE group. The appropriateness of empirical prescriptions of cefepime and piperacillin/tazobactam was significantly higher in the DUE group (93.5% vs. 83.5%; P = 0.003). Drug utilization evaluation was significantly associated with appropriate empirical prescriptions (adjusted OR 5.32: 95% CI 1.80-15.73; P = 0.003). Prescriptions in critical care wards and urinary tract infections (UTIs) were associated with not fulfilling the DUE criteria for appropriateness. CONCLUSIONS: Drug utilization evaluation could improve the appropriateness of empirical use of cefepime and piperacillin/tazobactam in pediatric patients. Patients in critical care units and with UTIs appeared to be associated with inappropriate empirical treatment.

Enterovirus 71-Induced Autoimmune Hemolytic Anemia in a Boy.

Autoimmune hemolytic anemia (AIHA) can be induced by recent or concomitant infections. Many infectious agents are postulated to be associated with this condition. Treatment of infection induced AIHA still varies. This report describes a previously healthy Thai boy who developed AIHA associated with enterovirus-71 infection. He was successfully treated with oral prednisone.

Handshake stewardship reduces carbapenem prescription in a pediatric critical care setting.

BACKGROUND: Intensive care unit (ICU) settings typically have a high-volume prescription of carbapenems. Antimicrobial stewardship programs (ASPs) aim to promote appropriate antibiotic use. Handshake stewardship (HS) is adapted from ASPs but focuses on direct feedback to physicians who prescribed antibiotics regarding the appropriateness of antibiotic prescription. This study aimed to evaluate the impact and acceptability of HS on carbapenem consumption in pediatric critical care settings. METHODS: This study was conducted over 18 months spanning pre-and post-implementation of HS. Carbapenem prescriptions were automatically discontinued during the pre-implementation period after 72 h if no indications existed. During the post-implementation, HS was performed by direct feedback to ICU physicians regarding the appropriateness of carbapenem prescriptions within 24 h. The primary outcome was the carbapenem consumption rate, defined as days of therapy (DOT)/1,000 patient-ICU days. Secondary outcomes were the acceptability of HS, length of critical care stay (LOCS), 30-day infection-related mortality rate, and the rate of carbapenem-resistant Enterobacteriaceae (CRE). RESULTS: There were 212 carbapenem prescriptions (163 patients) and 174 carbapenem prescriptions (110 patients) in the pre-and post-implementation periods, respectively. Carbapenem consumption decreased significantly from 667 to 369 DOT/1,000 patient-ICU days, with a median difference of 292 DOT/1,000 patient-ICU days (P < 0.001; 95% confidence interval: 175-408) after HS implementation. The acceptability of the HS was 95.4%. The LOCS, 30-day infection-related mortality, and CRE rate were not significantly different between pre-and post-implementation periods. CONCLUSIONS: Handshake stewardship significantly reduced carbapenem prescription in critically ill pediatric patients without negatively affecting patient outcomes.

Target Enrichment Metagenomics Reveals Human Pegivirus-1 in Pediatric Hematopoietic Stem Cell Transplantation Recipients.

Human pegivirus-1 (HPgV-1) is a lymphotropic human virus, typically considered nonpathogenic, but its infection can sometimes cause persistent viremia both in immunocompetent and immunosuppressed individuals. In a viral discovery research program in hematopoietic stem cell transplant (HSCT) pediatric patients, HPgV-1 was detected in 3 out of 14 patients (21.4%) using a target enrichment next-generation sequencing method, and the presence of the viruses was confirmed by agent-specific qRT-PCR assays. For the first time in this patient cohort, complete genomes of HPgV-1 were acquired and characterized. Phylogenetic analyses indicated that two patients had HPgV-1 genotype 2 and one had HPgV-1 genotype 3. Intra-host genomic variations were described and discussed. Our results highlight the necessity to screen HSCT patients and blood and stem cell donors to reduce the potential risk of HPgV-1 transmission.

Associations of lymphocyte subpopulations with clinical phenotypes and long-term outcomes in juvenile-onset systemic lupus erythematosus.

OBJECTIVE: Juvenile-onset systemic lupus erythematosus (JSLE) is a complex and heterogeneous immune-mediated disease. Cellular components have crucial roles in disease phenotypes and outcomes. We aimed to determine the associations of lymphocyte subsets with clinical manifestations and long-term outcomes in JSLE patients. METHODS: A cohort of 60 JSLE patients provided blood samples during active disease, of whom 34 provided further samples during inactive disease. In a longitudinal study, blood samples were obtained from 49 of the JSLE patients at 0, 3, and 6 months. The healthy control (HC) group consisted of 42 age-matched children. Lymphocyte subsets were analyzed by flow cytometry. RESULTS: The percentages of CD4+ T, γδ T, and NK cells were significantly decreased in JSLE patients compared with HC, while the percentages of CD8+ T, NKT, and CD19+ B cells were significantly increased. The percentage of regulatory T cells (Tregs) was significantly lower in JSLE patients with lupus nephritis (LN) than in non-LN JSLE patients and HC. The patients were stratified into high and low groups by the median frequency of each lymphocyte subset. The γδ T cells high group and NK cells high group were significantly related to mucosal ulcer. The CD4+ T cells high group was significantly associated with arthritis, and the NKT cells high group was substantially linked with autoimmune hemolytic anemia. The CD8+ T cells low group was mainly related to vasculitis, and the Tregs low group was significantly associated with LN. The percentage of Tregs was significantly increased at 6 months of follow-up, and the LN JSLE group had a lower Treg percentage than the non-LN JSLE group. Predictors of remission on therapy were high Tregs, high absolute lymphocyte count, direct Coombs test positivity, and LN absence at enrollment. CONCLUSION: JSLE patients exhibited altered lymphocyte subsets, which were strongly associated with clinical phenotypes and long-term outcomes.

Anti-HIV serological test algorithms to reduce false-positive and inconclusive results for low HIV prevalence and resource-limited areas.

A false-positive anti-human immunodeficiency virus (HIV) test result can have devastating consequences. Sequential HIV serological testing is a strategy that could be applied in resource-limited settings to reduce false-positive results when a nucleic acid test is not affordable. We aimed to compare the results of sequential anti-HIV testing algorithms recommended by the national guidelines and our hospital algorithm in the setting of low HIV prevalence. We retrospectively reviewed individuals whose anti-HIV tested positive by Architect HIV Ag/Ab Combo with a signal/cut-off ratio of 1.00-20.00 between January 2015 and June 2016 at a university hospital in Bangkok, Thailand. A total of 111,224 samples were requested for anti-HIV tests during the study period. Sixty-six adults and nine children/adolescents met the inclusion criteria of this study. Compared to the national guidelines, our hospital HIV diagnosis algorithm could identify two individuals with false-positive anti-HIV tests and a reduction of inconclusive diagnoses from 45 to one adult cases (p <.001). It also eliminated inconclusive diagnoses in four non-infected children with HIV-negative mothers. Our hospital HIV diagnosis algorithm can reduce the number of HIV misdiagnoses of serological tests in an area with low HIV prevalence. The sequential HIV serological test algorithms should be reviewed and evaluated in each institute.

Immunogenicity of varicella zoster vaccine in pediatric liver transplantation.

BACKGROUND: Pediatric liver transplant (LT) candidates often miss complete varicella-zoster virus (VZV) vaccination before LT. We aimed to evaluate the immunogenicity of two doses of VZV vaccines in pediatric LT candidates younger than 2 years and persistence of its immunogenicity after LT. METHODS: Patients aged 9-24 months were enrolled before LT. The first dose of VZV vaccine was given at 9 months, and the second dose was given at between 1 to 3 months later, and at least 4 weeks before LT. Varicella-zoster IgG (VZG) was used to detect immunoglobulin G antibodies to VZV and was reported as a test value (TV). A test value ≥ 0.9 was considered as seropositive. TV was measured at enrollment, 1 month after the first and the second dose of VZV vaccine, before LT, and 3 and 6 months after LT. RESULTS: Fourteen children were enrolled in this prospective cohort study. The median age at the first and the second dose of VZV vaccine was 11.5 months (IQR 9-12) and 13 months (IQR 12-33), respectively. The seroconversion rate was 66.7% (8/12) and 70% (7/10) after the first and second VZV vaccine doses, respectively. Seven of nine patients who underwent LT had two doses of VZV vaccine. Six patients were seropositive before LT, which persisted at 3 to 6 months after LT. Of two patients who received only one dose, TV was not detected after LT. CONCLUSIONS: The two doses of VZV vaccine appeared to be more immunogenic than one dose in pediatric LT candidates aged less than 2 years.

Profiles of CD4+, CD8+, and regulatory T cells and circulating cytokines in hookworm-infected children in southern Thailand.

Hookworm infection is the most common human helminthic infection in the rural areas of southern Thailand. There is little information on the induced cellular immune responses in hookworm-infected children. The present study aimed to investigate the cellular immune responses, regulatory T cells (Tregs), Th1-type cytokines (interleukin (IL)-2 and interferon (IFN)-γ), a Th2-type cytokine (IL-5) and IL-10, which is one of the cytokines secreted by Tregs in hookworm-infected children. Twenty-nine schoolchildren diagnosed with hookworm infections and 28 healthy controls were enrolled in the study. CD4+ and CD8+ T cells and Tregs in whole blood were analyzed using flow cytometry. Plasma IL-2, IL-5, IL-10 and IFN-γ concentrations were quantified by enzyme-linked immunosorbent assay (ELISA). The median CD4+ T cell frequency was significantly higher in hookworm-infected children than healthy controls. Compared to healthy controls, hookworm-infected children had a significantly increased absolute number of Tregs. No differences in circulating CD8+ T cell median frequency or absolute numbers were observed among hookworm-infected children or healthy controls. Elevated IL-2 and IL-10 concentrations were found in hookworm-infected children. Moreover, the absolute number of Tregs was significantly positively correlated with the plasma IL-10 concentration (rs = 0.406, P = 0.029). This study showed that hookworm-infected schoolchildren had significantly different immune responses than healthy controls, including an increase in the CD4+ T cell number, a significant induction of Tregs and significantly elevated circulating IL-10 levels. These alterations could be the mechanism underlying the immunomodulation that alleviates allergic diseases among hookworm-infected individuals.

Bloodstream bacterial infections in thalassemic pediatric and adolescent patients after hematopoietic stem cell transplantation.

BACKGROUND: Thalassemic patients usually require regular blood transfusions; however, HSCT can provide a cure. Incidence of IBI in pediatric patients post-HSCT is still scant. OBJECTIVES: This study aimed to explore whether thalassemic patients had a different incidence of post-HSCT IBI compared with patients with other underlying diseases. Factors associated with IBI in the pediatric population undergoing HSCT were also investigated. METHODS: In this retrospective cohort study, clinical data of pediatric patients who underwent HSCT during the period from 2011 to 2016 were reviewed and analyzed. The primary outcome was incidence of IBI within 1-year post-HSCT. RESULTS: Of 123 patients, 53 were thalassemic. IBI was diagnosed in 23 patients within 1 year after HSCT (incidence: 19.5 episodes/1000 patients/month). The IBI incidence was lower in thalassemic patients than in patients with other underlying diseases (6.9 vs. 31.6 episodes/1000 patients/month). Having thalassemia as an underlying disease was the only factor associated with lower IBI in pediatric post-HSCT patients (hazard ratio: 0.245; 95% confidence interval, 0.080-0.748). In post-HSCT thalassemic patients, IBI mostly occurred within 100 days after HSCT, and most of these cases had catheter-related blood stream infection. The risk of IBI tended higher for haploidentical HSCT, but this difference was not statistically significantly different. CONCLUSION: The IBI incidence after HSCT was lower in thalassemic patients than in those with other underlying diseases. Catheter-related blood stream infection was the major IBI in these patients. IBI was not a major complication in thalassemic pediatric patients undergoing HSCT.

Association between adenovirus infection and mortality outcome among pediatric patients after hematopoietic stem cell transplant.

BACKGROUND: Adenovirus can cause severe diseases in post-hematopoietic stem cell transplant (HSCT) patients. Because these patients also have many other factors contributing to mortality, it remains controversial whether adenovirus infection itself contributes to increased mortality in these patients. OBJECTIVE: To determine if adenovirus infection contributes to mortality in pediatric post-HSCT patients. METHODS: This retrospective cohort study was performed in post HSCT patients, aged 0-18 years old, admitted at Ramathibodi Hospital from 2016 to 2020. Adenovirus infection was defined as the detection of adenovirus in blood or urine by polymerase chain reaction. Multivariate cox regression was used to identify factors associated with death. RESULTS: The incidence of overall adenovirus infection (viremia or viruria) in this cohort was 20.8% (26 out of 125 enrolled patients). From the multivariate cox regression analysis, overall adenovirus infection was not significantly associated with death (hazard ratio [HR]: 2.41; 95% confidence interval [CI]: 0.96-6.06; p = .060). However, presence of viremia (HR: 3.90; 95% CI: 1.40-10.86; p = .009), having maximal serum viral load > 10 000 copies/ml (HR: 3.70; 95% CI: 1.20-11.38; p = .023), presence of end-organ diseases (HR: 3.44; 95% CI: 1.18-10.01; p = .023) were associated with mortality. Underlying diseases requiring long-term immunosuppressive drugs before HSCT, invasive fungal disease, invasive bacterial infection, cytomegalovirus infection, and longer engraftment time were also associated with mortality. CONCLUSION: Overall adenovirus infection does not appear to play a significant role in mortality in pediatric post-HSCT patients. However, more invasive forms of adenovirus infection were associated with mortality in these patients.

Invasive Fungal Disease Among Pediatric and Adolescent Patients Undergoing Itraconazole Prophylaxis After Hematopoietic Stem Cell Transplantation.

BACKGROUND: Invasive fungal disease (IFD) is a major cause of morbidity and mortality in patients after hematopoietic stem cell transplantation (HSCT). Itraconazole has been used for prevention of IFD, but data related to incidence and associated factors of IFD in pediatric and adolescent patients on itraconazole prophylaxis remain scarce. OBJECTIVES: To identify incidence and risk factors associated with IFD among pediatric and adolescent patients receiving itraconazole prophylaxis after HSCT. METHODS: Patients younger than 21 years who received itraconazole prophylaxis after HSCT from January 2007 to December 2016 were retrospectively enrolled. Incidence of IFD within 1 year and associated factors were analyzed. RESULTS: All patients received itraconazole during the pre-engraftment period. Of 170 patients, 29 had IFD, with an incidence of 17.1% at 1 year. IFD at 1 year was significantly associated with increased mortality. Of 29 patients with IFD, only 9 developed IFD while on itraconazole prophylaxis (5.3%), all of whom had invasive pulmonary aspergillosis. No invasive candidiasis occurred during itraconazole prophylaxis. Prolonged neutropenia (hazard ratio [HR] = 1.08; 95% confidence interval [CI], 1.02-1.13), graft-versus-host disease within 100 days after transplantation (HR = 3.17; 95% CI, 1.17-8.57), and using etoposide in preconditioning regimens (HR = 21.60; 95% CI, 2.44-190.95) were significantly associated with IFD at 1 year. No patients had to discontinue itraconazole because of its adverse effects. CONCLUSIONS: Itraconazole proffered good efficacy for prevention of candidiasis during the pre-engraftment period. Most IFD episodes occurred after the engraftment period when itraconazole had been discontinued. During this period, patients with risk factors require appropriate fungal prophylaxis.