Increased Prevalence of the Electrocardiographic Early Repolarization Pattern in Young Patients With Vagally Mediated Syncope: A Case-Control Study.

Background: Electrocardiographic early repolarization (EER) is linked with idiopathic ventricular fibrillation in adults. It is frequently seen in children, with poorly understood significance. Some evidence suggests that it could be a vagally mediated phenomenon. A retrospective case-control study was undertaken to test the hypothesis that EER is more common among children with typical vasovagal syncope (VVS) than among their peers with nonvagal syncope (NVS) or with no syncope. Methods: Patients aged 4-18 years with syncope were identified by a single-centre database search followed by a review of history for features of VVS (n = 150) or NVS (n = 84). The first available electrocardiogram (ECG) for VVS or for NVS was retrieved. Age- and sex-matched children with no known syncope or heart disease were then identified (n = 216). ECGs were assessed separately for EER based on published criteria by 2 observers blinded to patients' clinical status. Results: Mean age was 12.3 ± 3.2 years, and heart rate was 74.2 ± 16.5 beats/min. EER was more prevalent in VVS (33.3%) than among patients with NVS (19.1%; odds ratio: 2.29; confidence interval: 1.32-5.50) or among those with no syncope (12.5%; odds ratio: 3.14; confidence interval: 1.81-5.46). Heart rates were significantly lower in VVS and NVS (heart rate: 70.1 ± 13.8 and 70.7 ± 12.4 beats/min, respectively) compared with children with no syncope (heart rate: 78.2 ± 18.0 beats/min), both P < 0.001. Conclusions: EER is more common in paediatric patients with VVS than those with NVS or without syncope, consistent with a possible vagal contribution to the ECG finding.

Contexte: La repolarisation précoce (RP) à l'électrocardiogramme (ECG) est liée à une fibrillation ventriculaire idiopathique chez les adultes. Fréquente chez les enfants, sa signification est toutefois nébuleuse. Certaines données laissent penser qu'il pourrait s'agir d'un phénomène d'origine vagale. Une étude rétrospective cas-témoins a donc été réalisée dans le but de vérifier l'hypothèse selon laquelle la RP à l'ECG est plus courante chez les enfants atteints de syncope vasovagale (SVV) typique que chez leurs pairs atteints de syncope non vagale (SNV) ou non atteints de syncope. Méthodologie: Des patients de 4 à 18 ans atteints de syncope ont été recensés au moyen d'une recherche dans la base de données d'un centre, suivie d'un examen des antécédents visant à retracer des manifestations de SVV (n = 150) ou de SNV (n = 84). Le premier ECG disponible traduisant une SVV ou une SNV a été récupéré. Un appariement selon l'âge et le sexe entre les sujets atteints et des enfants qui n'étaient pas atteints de syncope ni de maladie cardiaque (n = 216) a ensuite été effectué. Deux observateurs qui ne connaissaient pas l'état clinique des enfants ont évalué les ECG séparément, à la recherche d'une RP, en se basant sur les critères publiés. Résultats: L'âge moyen des sujets était de 12,3 ± 3,2 ans et la fréquence cardiaque moyenne, de 74,2 ± 16,5 battements/minute. La prévalence de la RP à l'ECG était plus élevée chez les patients atteints de SVV (33,3 %) que chez les patients atteints de SNV (19,1 %; rapport de cotes [RC] : 2,29; intervalle de confiance [IC] : 1,32-5,50) ou les enfants non atteints de syncope (12,5 %; RC : 3,14; IC : 1,81-5,46). La fréquence cardiaque (FC) était significativement plus faible chez les sujets atteints de SVV ou de SNV (FC : 70,1 ± 13,8 et 70,7 ± 12,4 battements/minute, respectivement), en comparaison des enfants non atteints de syncope (FC : 78,2 ± 18,0 battements/minute); p < 0,001 dans les deux cas. Conclusion: La repolarisation précoce à l'ECG est plus courante chez les enfants atteints de syncope vasovagale que chez les enfants atteints de syncope non vagale ou non atteints de syncope, ce qui concorde avec une possible composante vagale dans le tracé de l'ECG.

The pandemic is gone but its consequences are here to stay: avascular necrosis following corticosteroids administration for severe COVID-19.

BACKGROUND: In patients with COVID-19 infection and respiratory insufficiency, corticosteroid (CCS) administration is recommended. Among the wide range of complications and interactions, time-limited high-dose CCS administration might promote avascular necrosis (AVN) in a cumulative dose. This systematic review updated the current evidence and characterises the trend of AVN following time-limited high-dose CCS administration in patients who had severe COVID-19, discussing management strategies and outcomes. METHODS: This systematic review was conducted according to the 2020 PRISMA statement. In October 2023, the following databases were accessed: PubMed, Web of Science, Google Scholar, and Scopus restricting the search to the years 2019 to 2023. All the clinical studies which investigated the association between time-limited high-dose CCS administration in patients with severe COVID-19 infection and AVN were accessed. RESULTS: A total of 245 patients (9 studies) who experienced AVN following COVID-19 were included in the present investigation. 26% (63 of 245 included patients) were women. The mean age of the patients was 42.9 ± 17.7 years. Four studies focused on AVN of the hip and two on the knee, and the other studies included patients with AVN from mixed areas of the body (spine, pelvis, and shoulder). The mean time elapsed from COVID-19 infection to the development of symptomatic AVN was 79.4 ± 59.2 days (range, 14 to 166 days). CONCLUSION: It is possible that even time-limited high-dose CCS administration in patients with severe COVID-19 infection increased the incidence of AVN. The mean time elapsed from COVID-19 infection to the development of symptomatic AVN was approximately 80 days. Given the high risk of bias in all the included studies, the quality of recommendations of the present investigation is low, and no reliable conclusion can be inferred.

Severe disease during both primary and secondary dengue virus infections in pediatric populations.

Dengue is a global epidemic causing over 100 million cases annually. The clinical symptoms range from mild fever to severe hemorrhage and shock, including some fatalities. The current paradigm is that these severe dengue cases occur mostly during secondary infections due to antibody-dependent enhancement after infection with a different dengue virus serotype. India has the highest dengue burden worldwide, but little is known about disease severity and its association with primary and secondary dengue infections. To address this issue, we examined 619 children with febrile dengue-confirmed infection from three hospitals in different regions of India. We classified primary and secondary infections based on IgM:IgG ratios using a dengue-specific enzyme-linked immunosorbent assay according to the World Health Organization guidelines. We found that primary dengue infections accounted for more than half of total clinical cases (344 of 619), severe dengue cases (112 of 202) and fatalities (5 of 7). Consistent with the classification based on binding antibody data, dengue neutralizing antibody titers were also significantly lower in primary infections compared to secondary infections (P ≤ 0.0001). Our findings question the currently widely held belief that severe dengue is associated predominantly with secondary infections and emphasizes the importance of developing vaccines or treatments to protect dengue-naive populations.

A Tertiary Care Centre Experience of Recurrent Giant Cell Tumor Around the Knee Joint.

INTRODUCTION: Giant cell tumor (GCT) is a benign but locally aggressive bone tumor. It has a peak incidence between 30-40 years with a predilection for the epiphyseal/metaphyseal region of bone. The most common locations for bone GCT are the distal femur, proximal tibia, distal radius, and sacrum in decreasing order. MATERIAL AND METHODS: In this retrospective study, 22 patients (13 females and nine males) with recurrent giant cell tumors around the knee joint between 2009-2022, with a mean age of 30.2 years (range: 18-55) were included. The patients were followed up monthly for three months, three-monthly for the next two years, six-monthly for the next five years, and thereafter, yearly. The mean follow-up period was 36.97 months (range 23-120 months). RESULTS: There were 19 recurrences after curettages and three after resections. Re-extended curettage was done in 17 cases and the resultant cavities were filled with autologous bone grafts in six and with polymethyl methacrylate (PMMA) cement in the other 11 cases. Reconstruction with megaprosthesis was done in two patients whereas knee arthrodesis was done in two patients after wide resection. The average Musculoskeletal Tumor Society (MSTS) score of our series of 22 patients was 23.1 (Range: 19-30). CONCLUSION: Campanacci grade 1 and 2 lesions can be successfully treated with extended curettage and bone grafting/bone cementing. For patients with grade 3 lesions, there are two options available according to the financial status of the patient; the first option is reconstruction with prosthesis and the other option is arthrodesis.

Recurrent Giant Cell Tumour of Distal End Radius: Treatment and Outcomes After Further Surgeries.

INTRODUCTION: Distal end radius is the second most common location for giant cell tumours (GCTs) followed by the knee. Like at any other location, they are treated with extended curettage or resection but reportedly have an increased propensity for recurrence. This study aims to treat the recurrent distal end radius GCTs and their outcome after further surgeries. PATIENTS AND METHODS: This study was conducted retrospectively from 2009 to 2021 and included 32 patients with recurrent distal end radius GCTs with a mean age of 29.53 years (range: 18-45 years). Twenty-five recurrences occurred after curettage and seven after resection. Twelve lesions were treated with further extended curettage. Nineteen recurrent lesions were treated with resection and arthrodesis. One out of two soft tissue recurrences was treated with en bloc resection. The mean follow-up period was 45.25 months (range: 24-120). RESULTS: The patients with joint preservations treated with further curettage and those where resection of soft tissue recurrences was done with salvage of joint had better functional outcomes with a mean Musculoskeletal Tumor Society (MSTS) score of 26.53 (Range: 22-30). The cases with arthrodesis had an average score of 23.75 (Range: 20-26). The overall average MSTS score was 24.89. CONCLUSIONS: We conclude that local recurrence contained within the bone can be re-curetted. The isolated soft tissue recurrences can be re-excised. The bony lesions with extensive soft tissue extension should be treated with resection and reconstruction. The re-recurrence rate after further adequate treatment does not increase much.

Outcomes of Wide Resection of Soft-Tissue Sarcoma of the Extremity: A Retrospective Analysis.

Background Soft-tissue sarcomas (STSs) are a rare heterogeneous group of tumors. Good functional results can be achieved with tumor excision in combination with suitable supplemental adjuvant therapies if needed. This study aimed to investigate the outcomes of wide resection of STS of the extremities. Methodology In this retrospective study, a total of 139 patients diagnosed with STS of the extremities by radiological and/or histopathological study/biopsy were included. All patients irrespective of metastasis were included. Results The mean age of the patients in our study was 43.5 ± 18.89 years. Overall, the mean tumor size was found to be 11.81 ± 6.218 cm. Malignant fibrous histiocytoma was the most common histology encountered (41%). Synovial sarcoma was the second most common histology encountered (14.38%). Recurrence was observed in 14 (10.1%) patients. The overall survival was 64.7% in our study. Conclusions The surgical margin achieved during the surgery is the most detrimental factor in local tumor control, and the overall survival of the patient after resection mainly depends on the stage of the tumor.

Contrasting behavior between the three human monocyte subsets in dengue pathophysiology.

Monocytes are known to play a critical role in dengue pathophysiology. However, which monocyte subset expresses what inflammatory mediator(s) and what transcriptional features distinguish each of the monocyte subset in vivo remain poorly understood. In this study we provide a detailed transcriptional analysis of the three human monocyte subsets in healthy children and in children with dengue febrile illness. Notably, we found that the CD14+ CD16high intermediate monocyte subset from dengue patients highly upregulated key genes involved in mediating inflammation, endothelial dysfunction, vascular permeability, tissue extravasation, and clot prevention compared to healthy children. The CD14+CD16low classical monocytes shared some of these features. These two subsets increased massively in patients with severe dengue. By contrast, the CD14-CD16high nonclassical monocyte subset upregulated key genes involved in vasoconstriction, endothelial barrier stability, and are involved in endothelial patrolling while showing a significant decline from circulation. These findings improve our understanding of monocyte responses in dengue.

Identification and characterization of novel infection associated transcripts in macrophages.

By analysis of lncRNA expression profiles of macrophages in response to Mycobacterium tuberculosis (Mtb) infection, we identified novel highly expressed transcripts, unique in encompassing a protein coding transcript- Cytidine Monophosphate Kinase 2 (CMPK2) and a previously identified lncRNA- Negative Regulator of Interferon Response (NRIR). While these transcripts (TILT1, 2,3 - TLR4 and Infection induced Long Transcript) are induced by virulent Mtb as well as lipopolysaccharide (LPS) early, lack of/delayed expression in non-viable Mtb/BCG infected cells, respectively, suggest an important role in macrophage responses. The elevated expression by 3 hr in response to fast growing bacteria further emphasizes the importance of these RNAs in the macrophage infection response. Overall, we provide evidence for the presence of multiple transcripts that form a part of the early infection response programme of macrophages.Abbreviations: IFN: Interferon; NRIR: negative regulator of interferon response; CMPK2: cytidine/ uridine monophosphate kinase; LPS: lipopolysaccharide; LAM: Lipoarabinomannan; PIMs: Phosphatidylinositol Mannosides; TILT1, 2,3: TLR4 and Infection induced Long Transcript; TLR4: Toll-like receptor 4; Mtb: Mycobacterium tuberculosis; BCG: Mycobacterium bovis BCG; MDMs: human monocyte derived macrophages.

Immunophenotyping and Transcriptional Profiling of Human Plasmablasts in Dengue.

Plasmablasts represent a specialized class of antibody-secreting effector B cells that transiently appear in blood circulation following infection or vaccination. The expansion of these cells generally tends to be massive in patients with systemic infections such as dengue or Ebola that cause hemorrhagic fever. To gain a detailed understanding of human plasmablast responses beyond antibody expression, here, we performed immunophenotyping and RNA sequencing (RNA-seq) analysis of the plasmablasts from dengue febrile children in India. We found that plasmablasts expressed several adhesion molecules and chemokines or chemokine receptors that are involved in endothelial interactions or homing to inflamed tissues, including skin, mucosa, and intestine, and upregulated the expression of several cytokine genes that are involved in leukocyte extravasation and angiogenesis. These plasmablasts also upregulated the expression of receptors for several B-cell prosurvival cytokines that are known to be induced robustly in systemic viral infections such as dengue, some of which generally tend to be relatively higher in patients manifesting hemorrhage and/or shock than in patients with mild febrile infection. These findings improve our understanding of human plasmablast responses during the acute febrile phase of systemic dengue infection. IMPORTANCE Dengue is globally spreading, with over 100 million clinical cases annually, with symptoms ranging from mild self-limiting febrile illness to more severe and sometimes life-threatening dengue hemorrhagic fever or shock, especially among children. The pathophysiology of dengue is complex and remains poorly understood despite many advances indicating a key role for antibody-dependent enhancement of infection. While serum antibodies have been extensively studied, the characteristics of the early cellular factories responsible for antibody production, i.e., plasmablasts, are only beginning to emerge. This study provides a comprehensive understanding of the transcriptional profiles of human plasmablasts from dengue patients.

Chikungunya-specific IgG and neutralizing antibody responses in natural infection of Chikungunya virus in children from India.

Chikungunya virus (CHIKV) infection is endemic in many different countries. CHIKV outbreaks are emerging in new areas and re-emerging in previously exposed geographical regions, thus making it a significant public health concern. CHIKV infections are often clinically inapparent, especially in children, which poses a challenge to testing and evaluating any vaccine. During CHIKV infection, CHIKV-specific antibodies are produced, and some of these antibodies can neutralize viruses released from infected cells before they can enter uninfected cells. In this study, we evaluated IgG binding and neutralizing antibody responses in paired serum samples from CHIKV-infected children and those with other febrile illness, using a recombinant truncated E2 protein and whole CHIKV particles as test antigens. Antibody detection using the truncated E2 protein showed a significant overlap between CHIKV-infected subjects and those with other febrile illnesses. This overlap was greater when binding antibody titers were determined using fixed CHIKV particles as the test antigen. Acute- and convalescent-phase sera collected from children after CHIKV infection showed significant differences in their neutralizing capacity. The neutralizing and binding antibody response showed a significant positive correlation. We detected IgG antibodies in most cases during the acute phase of infection. This was observed at two different geographical locations, one of which is not considered highly endemic. Conventional wisdom would suggest this to be a marker of re-infection (secondary infection). However, dissenting opinions have been voiced in other viral diseases (such as Ebola) where studies have detected IgG in acute illness. In the absence of any significant body of work documenting secondary CHIKV infections, we believe further work is needed to understand the early IgG response that we observed.

Application of ultrasound in combination with other technologies in food processing: A review.

The use of non-thermal processing technologies has been on the surge due to ever increasing demand for highest quality convenient foods containing the natural taste & flavor and being free of chemical additives and preservatives. Among the various non-thermal processing methods, ultrasound technology has proven to be very valuable. Ultrasound processing, being used alone or in combination with other processing methods, yields significant positive results on the quality of foods, thus has been considered efficacious. Food processes performed under the action of ultrasound are believed to be affected in part by cavitation phenomenon and mass transfer enhancement. It is considered to be an emerging and promising technology and has been applied efficiently in food processing industry for several processes such as freezing, filtration, drying, separation, emulsion, sterilization, and extraction. Various researches have opined that ultrasound leads to an increase in the performance of the process and improves the quality factors of the food. The present paper will discuss the mechanical, chemical and biochemical effects produced by the propagation of high intensity ultrasonic waves through the medium. This review outlines the current knowledge about application of ultrasound in food technology including processing, preservation and extraction. In addition, the several advantages of ultrasound processing, which when combined with other different technologies (such as microwave, supercritical CO2, high pressure processing, enzymatic extraction, etc.) are being examined. These include an array of effects such as effective mixing, retention of food characteristics, faster energy and mass transfer, reduced thermal and concentration gradients, effective extraction, increased production, and efficient alternative to conventional techniques. Furthermore, the paper presents the necessary theoretical background and details of the technology, technique, and safety precautions about ultrasound.

Respiratory properties of fresh black carrot (Dacus Carota L.) based upon non-linear enzyme kinetics approach.

The present work was undertaken with an objective to evaluate the impact of temperature on respiration rate of fresh black carrot using a non-linear enzyme kinetics approach. Two different models viz. Arrhenius equation (temperature effect) and enzyme kinetics (effect of temperature and headspace concentration) have been compared for predicting the respiration rate of black carrot. The respiratory behavior of black carrot was assessed using closed system technique at 5, 10 and 15 °C (± 1 °C) temperature and constant relative humidity (RH) of 85%. The O2 consumption and CO2 evolution rate values were 39.17, 58.88 and 68.08 ml kg-1 h-1; 22.15, 34.63 and 41.86 ml kg-1 h-1 after the attainment of steady-state condition at 5, 10 and 15 °C, respectively. The inhibition by evolved CO2 was found to be predominantly competitive at all temperatures. The average absolute deviation in O2 consumption and CO2 evolution rate for Arrhenius model was 3.5% and 5.3% while for enzyme kinetics model was 8.8% and 6.3%, respectively. Dependency of respiration rate of black carrot on temperature was well defined by Arrhenius model. The outcomes of the study can be further utilized to design the MAP (modified atmosphere packages) for fresh black carrot storage at 5 °C with 85% RH.

Serotype-specific detection of dengue viruses in a nonstructural protein 1-based enzyme-linked immunosorbent assay validated with a multi-national cohort.

BACKGROUND: Dengue virus (DENV) infections pose one of the largest global barriers to human health. The four serotypes (DENV 1-4) present different symptoms and influence immune response to subsequent DENV infections, rendering surveillance, risk assessments, and disease control particularly challenging. Early diagnosis and appropriate clinical management is critical and can be achieved by detecting DENV nonstructural protein 1 (NS1) in serum during the acute phase. However, few NS1-based tests have been developed that are capable of differentiating DENV serotypes and none are currently commercially available. METHODOLOGY/PRINCIPLE FINDINGS: We developed an enzyme-linked immunosorbent assay (ELISA) to distinguish DENV-1-4 NS1 using serotype-specific pairs of monoclonal antibodies. A total of 1,046 antibodies were harvested from DENV-immunized mice and screened for antigen binding affinity. ELISA clinical performance was evaluated using 408 polymerase chain reaction-confirmed dengue samples obtained from patients in Brazil, Honduras, and India. The overall sensitivity of the test for pan-DENV was 79.66% (325/408), and the sensitivities for DENV-1-4 serotyping were 79.1% (38/48), 80.41% (78/97), 100% (45/45), and 79.6% (98/123), respectively. Specificity reached 94.07-100%. SIGNIFICANCE: Our study demonstrates a robust antibody screening strategy that enabled the development of a serotype NS1-based ELISA with maximized specific and sensitive antigen binding. This sensitive and specific assay also utilized the most expansive cohort to date, and of which about half are from Latin America, a geographic region severely underrepresented in previous similar studies. This ELISA test offers potential enhanced diagnostics during the acute phase of infection to help guide patient care and disease control. These results indicate that this ELISA is a promising aid in early DENV-1-4 diagnosis and surveillance in regions of endemicity in addition to offer convenient monitoring for future vaccine interventions.

Respiratory Syncytial Virus-Induced Oxidative Stress Leads to an Increase in Labile Zinc Pools in Lung Epithelial Cells.

Zinc supplementation in cell culture has been shown to inhibit various viruses, like herpes simplex virus, rotavirus, severe acute respiratory syndrome (SARS) coronavirus, rhinovirus, and respiratory syncytial virus (RSV). However, whether zinc plays a direct antiviral role in viral infections and whether viruses have adopted strategies to modulate zinc homeostasis have not been investigated. Results from clinical trials of zinc supplementation in infections indicate that zinc supplementation may be beneficial in a pathogen- or disease-specific manner, further underscoring the importance of understanding the interaction between zinc homeostasis and virus infections at the molecular level. We investigated the effect of RSV infection on zinc homeostasis and show that RSV infection in lung epithelial cells leads to modulation of zinc homeostasis. The intracellular labile zinc pool increases upon RSV infection in a multiplicity of infection (MOI)-dependent fashion. Small interfering RNA (siRNA)-mediated knockdown of the ubiquitous zinc uptake transporter ZIP1 suggests that labile zinc levels are increased due to the increased uptake by RSV-infected cells as an antiviral response. Adding zinc to culture medium after RSV infection led to significant inhibition of RSV titers, whereas depletion of zinc by a zinc chelator, N,N,N',N'-tetrakis(2-pyridinylmethyl)-1,2-ethanediamine (TPEN) led to an increase in RSV titers. The inhibitory effect of zinc was specific, as other divalent cations had no effect on RSV titers. Both RSV infection and zinc chelation by TPEN led to reactive oxygen species (ROS) induction, whereas addition of zinc blocked ROS induction. These results suggest a molecular link between RSV infection, zinc homeostasis, and oxidative-stress pathways and provide new insights for developing strategies to counter RSV infection.IMPORTANCE Zinc deficiency rates in developing countries range from 20 to 30%, and zinc supplementation trials have been shown to correct clinical manifestations attributed to zinc deficiency, but the outcomes in the case of respiratory infections have been inconsistent. We aimed at understanding the role of zinc homeostasis in respiratory syncytial virus (RSV) infection. Infection of lung epithelial cell lines or primary small-airway epithelial cells led to an increase in labile zinc pools, which was due to increased uptake of zinc. Zinc supplementation inhibited RSV replication, whereas zinc chelation had an opposing effect, leading to increases in RSV titers. Increases in labile zinc in RSV-infected cells coincided with induction of reactive oxygen species (ROS). Both zinc depletion and addition of exogenous ROS led to enhanced RSV infection, whereas addition of the antioxidant inhibited RSV, suggesting that zinc is part of an interplay between RSV-induced oxidative stress and the host response to maintain redox balance.

Isolation and molecular characterization of dengue virus clinical isolates from pediatric patients in New Delhi.

OBJECTIVE: To characterize the in vitro replication fitness, viral diversity, and phylogeny of dengue viruses (DENV) isolated from Indian patients. METHODS: DENV was isolated from whole blood collected from patients by passaging in cell culture. Passage 3 viruses were used for growth kinetics in C6/36 mosquito cells. Parallel efforts also focused on the isolation of DENV RNA from plasma samples of the same patients, which were processed for next-generation sequencing. RESULTS: It was possible to isolate 64 clinical isolates of DENV, mostly DENV-2. Twenty-five of these were further used for growth curve analysis in vitro, which showed a wide range of replication kinetics. The highest viral titers were associated with isolates from patients with dengue with warning signs and severe dengue cases. Full genome sequences of 21 DENV isolates were obtained. Genome analysis mapped the circulating DENV-2 strains to the Cosmopolitan genotype. CONCLUSIONS: The replication kinetics of isolates from patients with mild or severe infection did not differ significantly, but the viral titers varied by two orders of magnitude between the isolates, suggesting differences in replication fitness among the circulating DENV-2.

Impact of HIV infection and highly active antiretroviral therapy (HAART) on B cell subpopulations in children.

B-cells play an important role in defending children against various infections. In view of scare data, we undertook this prospective cohort study to describe B cell compartment in HIV infected children (<5 years of age) and the effect of HAART on B cell subpopulations. HIV infected children (<5 years) from Pediatric HIV services of the Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, were recruited (April 2012-December 2015). The enrolled HIV-1 infected children (n = 59) were followed up regularly for 12 months; healthy controls (n = 51) included HIV uninfected children with no major illness. Flow cytometry was performed on fresh EDTA-treated blood samples to characterize B cell subpopulations. In HIV-infected children, marked depletion of naive (P = 0.003), non-switched memory (P = 0.02), mature (P = 0.0005), resting memory (P < 0.0001) B cells, and expansion of double negative memory (P < 0.0001), activated memory (P < 0.0001) and tissue like memory (P < 0.0001) B cells were observed as compared to healthy controls. In children started on HAART, at the end of 12 months of therapy, frequencies of non-switched memory (P = 0.04), switched memory (P = 0.01), and resting memory (P = 0.003) B cells were lower; activated memory (P = 0.04), and tissue-like memory (P = 0.0001) B cells were still higher than healthy controls. HIV infection resulted in reduced memory B cells in HIV infected children. Following HAART, there was normalization of some B cell subpopulations. The study emphasizes the need of re-vaccination in HIV infected children to maintain the memory B cell pool and adequate humoral immune response against infections.

Diagnostic Yield of Xpert MTB/RIF in Bronchoalveolar Lavage in Children with Probable Pulmonary Tuberculosis.

OBJECTIVE: To evaluate utility of Xpert MTB/RIF in bronchoalveolar lavage fluid in children with probable pulmonary tuberculosis. METHODS: Children with probable pulmonary tuberculosis with negative smear and Xpert on induced sputum/gastric aspirate were subjected to bronchoalveolar lavage (BAL) for Xpert assay and mycobacterial liquid culture. Data of children <14 y undergoing bronchoscopy for suspected MDR-TB (n=12) were also analyzed. The sensitivity of Xpert in BAL fluid for diagnosis of probable and confirmed pulmonary tuberculosis was calculated with clinico-radiological diagnosis and culture as gold standards, respectively. RESULTS: Of 41 enrolled children, 24 (58.5%) had Xpert positive in BAL fluid and 11 (26.8%) had culture confirmed tuberculosis (BAL fluid;10; sputum,1). The sensitivity of Xpert in BAL fluid among probable and culture confirmed tuberculosis cases was 58.5% (24/41) and 81.8% (9/11), respectively. CONCLUSION: Xpert in bronchoalveolar lavage fluid has good sensitivity in both probable and confirmed pulmonary tuberculosis in children.

Rapid antigen tests for dengue virus serotypes and Zika virus in patient serum.

The recent Zika virus (ZIKV) outbreak demonstrates that cost-effective clinical diagnostics are urgently needed to detect and distinguish viral infections to improve patient care. Unlike dengue virus (DENV), ZIKV infections during pregnancy correlate with severe birth defects, including microcephaly and neurological disorders. Because ZIKV and DENV are related flaviviruses, their homologous proteins and nucleic acids can cause cross-reactions and false-positive results in molecular, antigenic, and serologic diagnostics. We report the characterization of monoclonal antibody pairs that have been translated into rapid immunochromatography tests to specifically detect the viral nonstructural 1 (NS1) protein antigen and distinguish the four DENV serotypes (DENV1-4) and ZIKV without cross-reaction. To complement visual test analysis and remove user subjectivity in reading test results, we used image processing and data analysis for data capture and test result quantification. Using a 30-µl serum sample, the sensitivity and specificity values of the DENV1-4 tests and the pan-DENV test, which detects all four dengue serotypes, ranged from 0.76 to 1.00. Sensitivity/specificity for the ZIKV rapid test was 0.81/0.86, respectively, using a 150-µl serum input. Serum ZIKV NS1 protein concentrations were about 10-fold lower than corresponding DENV NS1 concentrations in infected patients; moreover, ZIKV NS1 protein was not detected in polymerase chain reaction-positive patient urine samples. Our rapid immunochromatography approach and reagents have immediate application in differential clinical diagnosis of acute ZIKV and DENV cases, and the platform can be applied toward developing rapid antigen diagnostics for emerging viruses.

Predictors of Microbiologically Confirmed Intrathoracic Tuberculosis.

OBJECTIVE: To identify risk factors for microbiologically confirmed intrathoracic tuberculosis in children. METHODS: Children, 6 mo to 15 y of age, attending the out-patient department of a tertiary care centre in India, with probable intrathoracic tuberculosis were enrolled. Microbiological confirmation of tuberculosis was defined as positivity on smear (Ziehl-Neelsen staining) and/or Xpert MTB/RIF and/or MGIT-960 culture. Association of various factors with microbiological confirmation were assessed by univariate and multivariate analysis. RESULTS: Microbiologic confirmation was documented in 39 (25%) of 153 patients enrolled. On univariate analysis, microbiological positivity was associated with female gender, higher mean (SD) age [136.6 (31.8) vs. 117.3 (41.4) mo], parenchymal lesion on chest radiograph, low body mass index for age, having symptoms of cough and weight loss, lower mean (SD) hemoglobin [10.4 (1.37) g/dl vs. 11(1.52) g/dl; p = 0.04], and higher mean (SD) monocyte: lymphocyte ratio [0.38 (0.30) vs. 0.24 (0.02); p = 0.37]. Higher proportion of microbiologically negative children were BCG vaccinated (95% vs. 79%; p = 0.002). On multivariate analysis, microbiological positivity showed significant association with low body mass index for age (p = 0.033) and higher monocyte: lymphocyte ratio (p = 0.037). CONCLUSIONS: Low body mass index for age and higher monocyte: lymphocyte ratios were associated with microbiological confirmation in children with intrathoracic tuberculosis.

Immunological and Virological Responses to Highly Active Antiretroviral Therapy in HIV-1 Infected Children.

OBJECTIVE: To evaluate immunological and virological outcomes in human immunodeficiency virus (HIV) infected children at six months of highly active antiretroviral therapy (HAART). METHODS: Records of HIV infected children <15-y-old were reviewed to identify those who were initiated highly active antiretroviral therapy between 2010 and 2014 and had CD4+ T cell percentage and HIV-1 viral load report at baseline visit and after 6 mo of initiation of the treatment. RESULTS: Seventy-four HIV infected children [26% girls, median age IQR 36 (24-108) mo] were included in the study. At the end of six months of HAART, median increase of 11% (6-15%) in CD4+ T cell percentage from the baseline levels was observed; nineteen (26%) children showed an increase in CD4+ T cell percentage of 15% or more at 6 mo. Viral load was undetectable (<47 copies/ml) in 27 (36.4%) children; 21 (28.3%) children had 47- < 500 copies/ml; 16 (21.6%) children had 500- < 10,000 copies/ml and 10 (13.5%) children had ≥10,000 copies/ml. At six months, only 15 (20.2%) children exhibited positive immuno-virological response to HAART (≥ 15% increase in CD4% and <47 HIV-1 RNA copies/ml). CONCLUSIONS: While HAART was effective in improving the immunological and virological parameters in the index cohort of children, virological responses were less robust.