Increased glucose availability sensitizes pancreatic cancer to chemotherapy

Pancreatic Ductal Adenocarcinoma (PDAC) is highly resistant to chemotherapy. Effective alternative therapies have yet to emerge, as chemotherapy remains the best available systemic treatment. However, the discovery of safe and available adjuncts to enhance chemotherapeutic efficacy can still improve survival outcomes. We show that a hyperglycemic state substantially enhances the efficacy of conventional single- and multi-agent chemotherapy regimens against PDAC. Molecular analyses of tumors exposed to high glucose levels reveal that the expression of GCLC (glutamate-cysteine ligase catalytic subunit), a key component of glutathione biosynthesis, is diminished, which in turn augments oxidative anti-tumor damage by chemotherapy. Inhibition of GCLC phenocopies the suppressive effect of forced hyperglycemia in mouse models of PDAC, while rescuing this pathway mitigates anti-tumor effects observed with chemotherapy and high glucose.

Liver Endothelium Microenvironment Promotes HER3-mediated Cell Growth in Pancreatic Ductal Adenocarcinoma

~90% metastatic pancreatic ductal adenocarcinoma (mPDAC) occurs in the liver, and the 5-year survival rate for patients with mPDAC is only at 3%. The liver has a unique endothelial cell (EC)-rich microenvironment, and preclinical studies showed that ECs promote cancer cell survival pathways by secreting soluble factors in a paracrine fashion in other types of cancer. However, the effects of liver ECs on mPDAC have not been elucidated. In this study, we used primary liver ECs and determined that liver EC-secreted factors containing conditioned medium (CM) increased PDAC cell growth, compared to control CM from PDAC cells. Using an unbiased receptor tyrosine kinase array, we identified human epidermal growth factor receptor 3 (HER3, also known as ErbB3) as a key mediator of liver EC-induced growth in PDAC cells with HER3 expression (HER3 +ve). We found that EC-secreted neuregulins activated the HER3-AKT signaling axis, and that depleting neuregulins from EC CM or blocking HER3 with an antibody, seribantumab, attenuated EC-induced functions in HER3 +ve PDAC cells, but not in cells without HER3 expression. Furthermore, we determined that EC CM increased PDAC xenograft growth in vivo, and that seribantumab blocked EC-induced growth in xenografts with HER3 expression. These findings elucidated a paracrine role of liver ECs in promoting PDAC cell growth, and identified the HER3-AKT axis as a key mediator in EC-induced functions in HER3 +ve PDAC cells. As over 70% mPDAC express HER3, this study highlights the potential of using HER3-targeted therapies for treating patients with HER3 +ve mPDAC.

Wild-type IDH1 inhibition enhances chemotherapy response in melanoma

BACKGROUND

Alternative treatment strategies in melanoma beyond immunotherapy and mutation-targeted therapy are urgently needed. Wild-type isocitrate dehydrogenase 1 (wtIDH1) has recently been implicated as a metabolic dependency in cancer. The enzyme protects cancer cells under metabolic stress, including nutrient limited conditions in the tumor microenvironment. Specifically, IDH1 generates NADPH to maintain redox homeostasis and produces α-ketoglutarate to support mitochondrial function through anaplerosis. Herein, the role of wtIDH1 in melanoma is further explored.

METHODS

The expression of wtIDH1 was determined by qRT-PCR, and Western blot in melanoma cell lines and the effect of wtIDH1 on metabolic reprogramming in melanoma was interrogated by LC-MS. The impact of wtIDH1 inhibition alone and in combination with chemotherapy was determined in cell culture and mouse melanoma models.

RESULTS

Melanoma patients express higher levels of the wtIDH1 enzyme compared to normal skin tissue, and elevated wtIDH1 expression portends poor patient survival. Knockdown of IDH1 by RNA interference inhibited cell proliferation and migration under low nutrient levels. Suppression of IDH1 expression in melanoma also decreased NADPH and glutathione levels, resulting in increased reactive oxygen species. An FDA-approved inhibitor of mutant IDH1, ivosidenib (AG-120), exhibited potent anti-wtIDH1 properties under low magnesium and nutrient levels, reflective of the tumor microenvironment in natura. Thus, similar findings were replicated in murine models of melanoma. In light of the impact of wtIDH1 inhibition on oxidative stress, enzyme blockade was synergistic with conventional anti-melanoma chemotherapy in pre-clinical models.

CONCLUSIONS

These results demonstrate the clinical potential of wtIDH1 inhibition as a novel and readily available combination treatment strategy for patients with advanced and refractory melanoma. Schematic shows increased wild-type IDH1 expression and activity as an adaptive response to metabolic stress induced by chemotherapy.

Abstract 2552: Effects of liver endothelium on pancreatic cancer growth and metabolism

Introduction: ~90% metastatic pancreatic ductal adenocarcinoma (mPDAC) are found in the liver, and 5-year survival rate for patients with mPDAC is only at 3%. Therefore, novel therapeutic strategies are urgently needed. A growing body of evidence suggest PDAC rely on mitochondrial function (oxidative phosphorylation, OXPHOS) for survival. However, PDAC liver metastases have been reported to have higher levels of glucose uptake compared to primary tumors suggesting that PDAC liver metastases may rely on glycolytic metabolism. Therefore, the relative metabolic and cellular profiles of primary and metastatic PDAC (mPDAC) remain unclear and the involved regulatory pathway(s) have not been elucidated. Our previous studies showed that liver endothelial cells (ECs) secreted soluble factors to promote the survival of colon cancer cells in a paracrine fashion. The influence of the liver EC microenvironment on mPDAC growth and metabolism has not been elucidated. In this study, we investigate the paracrine effects of liver ECs on the survival and metabolic profiles of PDAC and elucidate the involved mechanism(s).

Methods: Primary liver ECs were isolated from non-neoplastic liver. Conditioned medium (CM) from liver ECs were collected and then applied to PDAC cells, with CM from PDAC as control CM. Effects of CM on PDAC cell proliferation were measured by the MTT assay. Changes in phosphorylation of receptor tyrosine kinases (RTK) between PDAC CM and EC CM treated PADC cells were determined by a Phospho-RTK Array kit and then validated by Western blotting. Effects of EC CM on PDAC metabolism was assessed by ATP production with CellTiter-Glo and oxygen consumption rate with Agilent Seahorse Mito Stress Assay.

Results: Compared to PDAC CM, liver EC CM promoted proliferation in different PDAC cells. We found that human epidermal growth factor receptor 3 (HER3, also known asERBB3) was only expressed and activated in BxPC-3 cells (HER3+ve), in which the HER3-AKT signaling pathway was activated by EC CM. Furthermore, blocking HER3 activation with a humanized HER3 antibody, seribantumab, significantly blocked EC CM-induced AKT activation and cell proliferation. Moreover, depletion of neuregulin (NRG) from EC CM attenuated HER3-AKT activation and indicated that EC-secreted NRG might play a role in promoting PDAC growth. Furthermore, EC CM decreased the levels of ATP production and O2 consumption in PDAC cells, suggesting that EC cells reprogram PDAC metabolism away from OXPHOS mitochondrial metabolism.

Conclusions: Liver EC-secreted factors promoted PDAC growth in vitro and in vivo, and HER3 was expressed in a subset of PDAC cells and mediated EC-induced proliferation. Moreover, EC reprogramed PDAC metabolism towards glycolysis, and inhibiting the activation of HER3 shifted PDAC metabolism to OXPHOS. Our findings provide a new insight to develop new combination of HER antibody and OXPHOS inhibitor for treating patients with HER3+ve mPDAC.

Citation Format: Wei Zhang, Michel'le Wright, Moeez Rathore, Mehrdad Zarei, Jordan Winter, Rui Wang. Effects of liver endothelium on pancreatic cancer growth and metabolism [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2552.

Liver Endothelium Promotes HER3-mediated Cell Survival in Colorectal Cancer with Wild-type and Mutant KRAS

We previously identified that human epidermal growth factor receptor 3 (HER3, also known as ERBB3) is a key mediator in liver endothelial cell (EC) promoting colorectal cancer (CRC) growth and chemoresistance, and suggested HER3-targeted therapy as a strategy for treating patients with metastatic CRC (mCRC) in the liver. Meanwhile, KRAS mutations occur in 40-50% of mCRC and render CRC resistant to therapies targeting the other HER family protein epidermal growth factor receptor (EGFR). It is necessary to elucidate the roles of KRAS mutation status in HER3-mediated cell survival and CRC response to HER3 inhibition. In the present study, we used primary ECs isolated from non-neoplastic liver tissues to recapitulate the liver EC microenvironment. We demonstrated that liver EC-secreted factors activated CRC-associated HER3, and increased CRC cell survival in vitro and promoted CRC patient-derived xenograft tumor growth in vivo. Moreover, we determined that blocking HER3, either by siRNA knockdown or the humanized antibody seribantumab, blocked EC-induced CRC survival in vitro in both KRAS wild-type and mutant CRC cells, and the HER3 antibody seribantumab significantly decreased CRC tumor growth and sensitized tumors to chemotherapy in an orthotopic xenograft model with CRC tumors developed in the liver. In summary, our findings demonstrated that blocking HER3 had significant effects on attenuating liver EC-induced CRC cell survival independent of the KRAS mutation status. Implications: This body of work highlighted a potential strategy of using HER3 antibodies in combination with standard chemotherapy agents for treating patients with either KRAS wild-type or KRAS mutant mCRC.

Abstract PO-131: The role of liver endothelium on pancreatic cancer growth

Introduction: Pancreatic ductal adenocarcinoma (PDAC) has the highest mortality rate among major cancers in the United States, and the 5-year survival rate for patients with metastatic PDAC (mPDAC) is only at 3%. Past studies have shown that the paracrine secretion of soluble factors by endothelial cells (ECs) created a unique niche and promoted the survival of cancer cells (cell growth or chemoresistance) in other types of cancer. The liver is the main site of distant metastases in mPDAC, but the influence of the liver EC microenvironment on mPDAC has not been elucidated. In this study, we determined the paracrine effects of liver ECs on the survival of PDAC and identify involved mechanism. Methods: Primary liver ECs were isolated from non-neoplastic liver tissues to mimic the liver EC microenvironment. Conditioned medium (CM) from liver ECs were collected and then applied to PDAC cells, with CM from PDAC as control CM. Effects of CM on PDAC cell proliferation were measured by the MTT assay. Changes in phosphorylation of receptor tyrosine kinases (RTK) between PDAC CM and EC CM treated PADC cells were determined by a Phospho-RTK Array kit and then validated by Western blotting. Involved RKTs were blocked by antibodies for determining their roles in mediating EC effects on PDAC cells. Lastly, A xenograft tumor model was used to establish PDAC tumors and then treated xenograft mice were subcutaneously injected by either PADC CM or EC CM, and tumors growth was monitored and recorded to evaluate the effect of ECs on PADCs. Results: Compared to PDAC CM, EC CM promoted proliferation in 4 different PDAC cells. We found that human epidermal growth factor receptor 3 (HER3 or ERBB3) was only expressed and activated in BxPC-3 cells (HER3+ve), in which the HER3-AKT signaling pathway was activated by EC CM. Furthermore, blocking HER3 activation with a humanized HER3 antibody, seribantumab, completely blocked EC CM-induced AKT activation and cell proliferation. Moreover, depletion of neuregulin (NRG) from EC CM attenuated HER3-AKT activation and indicated that EC-secreted NRG might play a role in promoting PDAC growth. It is interesting that ERK activation was also observed but was not affected by HER3 inhibition. It implied that EGFR signaling pathway might also be involved in EC CM induced PDAC cell growth. Moreover, the combination of cetuximab, trastuzumab and seribantumab yielded the best inhibitory ability on EC CM promoted cell growth as compared to antibody alone or the combination of two of them. Finally, EC CM promoted PDAC tumor growth was also observed in BxPC-3 derived xenograft mouse model. Conclusions: Our results demonstrated that liver EC-secreted factors promoted PDAC growth either in vitro or in vivo, and HER3 was expressed in a subset of PDAC cells and mediated EC-induced proliferation. Moreover, EGFR pathway may also play a role in EC induced cell growth and needs to be addressed in the future study. Our findings suggest a potential of using the combination of HER antibodies/inhibitors for treating patients with HER3+ve mPDACs.

Citation Format: Wei Zhang, Michel’le Wright, Moeez Rathore, Ali Vaziri-Gohar, Jordan Winter, Rui Wang. The role of liver endothelium on pancreatic cancer growth [abstract]. In: Proceedings of the AACR Virtual Special Conference on Pancreatic Cancer; 2021 Sep 29-30. Philadelphia (PA): AACR; Cancer Res 2021;81(22 Suppl):Abstract nr PO-131.

Cancer cell-derived long pentraxin 3 (PTX3) promotes melanoma migration through a toll-like receptor 4 (TLR4)/NF-κB signaling pathway

Cutaneous melanoma is one of the most aggressive cancers characterized by a high plasticity, a propensity for metastasis, and drug resistance. Melanomas are composed of phenotypically diverse subpopulations of tumor cells with heterogeneous molecular profiles that reflect intrinsic invasive abilities. In an attempt to identify novel factors of the melanoma invasive cell state, we previously investigated the nature of the invasive secretome by using a comparative proteomic approach. Here, we have extended this analysis to show that PTX3, an acute phase inflammatory glycoprotein, is one such factor secreted by invasive melanoma to promote tumor cell invasiveness. Elevated PTX3 production was observed in the population of MITFlow invasive cells but not in the population of MITFhigh differentiated melanoma cells. Consistently, MITF knockdown increased PTX3 expression in MITFhigh proliferative and poorly invasive cells. High levels of PTX3 were found in tissues and blood of metastatic melanoma patients, and in BRAF inhibitor-resistant melanoma cells displaying a mesenchymal invasive MITFlow phenotype. Genetic silencing of PTX3 in invasive melanoma cells dramatically impaired migration and invasion in vitro and in experimental lung extravasation assay in xenografted mice. In contrast, addition of melanoma-derived or recombinant PTX3, or expression of PTX3 enhanced motility of low migratory cells. Mechanistically, autocrine production of PTX3 by melanoma cells triggered an IKK/NFκB signaling pathway that promotes migration, invasion, and expression of the EMT factor TWIST1. Finally, we found that TLR4 and MYD88 knockdown inhibited PTX3-induced melanoma cell migration, suggesting that PTX3 functions through a TLR4-dependent pathway. Our work reveals that tumor-derived PTX3 contributes to melanoma cell invasion via targetable inflammation-related pathways. In addition to providing new insights into the biology of melanoma invasive behavior, this study underscores the notion that secreted PTX3 represents a potential biomarker and therapeutic target in a subpopulation of MITFlow invasive and/or refractory melanoma.

Characterization of functional trait diversity among Indian cultivated and weedy rice populations

Weedy rice, a menace in rice growing areas globally, is biosimilar having attributes similar to cultivated and wild rice, and therefore is difficult to manage. A study was initiated to characterize the functional traits of 76 weedy rice populations and commonly grown rice cultivars from different agro-climatic zones for nine morphological, five physiological, and three phenological parameters in a field experiment under an augmented block design. Comparison between weedy and cultivated rice revealed a difference in duration (days) from panicle emergence to heading as the most variable trait and awn length as the least variable one, as evidenced from their coefficients of variation. The results of principal component analysis revealed the first three principal components to represent 47.3% of the total variation, which indicates an important role of transpiration, conductance, leaf-air temperature difference, days to panicle emergence, days to heading, flag leaf length, SPAD (soil-plant analysis development), grain weight, plant height, and panicle length to the diversity in weedy rice populations. The variations existing in weedy rice population are a major reason for its wider adaptability to varied environmental conditions and also a problem while trying to manage it.

Mitomycin-C: 'a ray of hope' in refractory corrosive esophageal strictures

Increasingly frequent dilation may become a self-defeating cycle in refractory stricture as recurrent trauma enhance, scar formation, and ultimately recurrence and potential worsening of the stricture. In 12 patients of caustic induced esophageal stricture, who failed to respond despite rigorous dilatation regimen for more than one year, a trial of topical mitomycin-C application to improve dilatation results was undertaken, considering the recently reported efficacy and safety of this agent. Mitomycin-C was applied for 2-3 minutes at the strictured esophageal segment after dilation with wire-guided Savary-Gilliard dilator. Patient was kept nil by mouth for 2-3 hours. After 4-6 sessions of mitomycin-C treatment, resolution of symptoms and significant improvement in dysphagia score and periodic dilatation index was seen in all 12 patients. Mitomycin-C topical application may be a useful strategy in refractory corrosive esophageal strictures and salvage patients from surgery.

Conservative management of a case of traumatic pancreatitis in childhood: a case report

Acute pancreatitis (AP) is relatively uncommon in pediatric age group. Traumatic injury is an important cause of AP in children. Ductal disruption resulting from pancreatic trauma usually needs surgical intervention. A three-and-a-half year old child presented with complaints of abdominal pain and distension following blunt trauma abdomen. Computed tomography of abdomen revealed presence of grade III pancreatic injury with fluid collection in lesser sac. The patient was managed with antibiotics and pigtail drainage and he improved. Therapy for traumatic pancreatitis in paediatric patients must be individualised. Even high grade injuries can be managed non-operatively.

Isolated right pulmonary artery agenesis with agenesis of right upper lobe and bronchiectasis of right lower lobe with anomalous arterial supply from celiac axis with normal venous drainage

Isolated unilateral absence of pulmonary artery (UAPA) is a rare congenital anomaly. When detected in infancy, the condition is commonly associated with cardiovascular defects which are more frequently associated with left pulmonary artery agenesis. Patients with isolated right pulmonary artery agenesis survive into adulthood with minimal or no symptoms and are diagnosed incidentally on the chest radiographs. We report a case of a 19-year-old female patient who presented to us with recurrent haemoptysis. She was symptomatic since the age of four years. We report the rare occurrence of UAPA on right side, agenesis of right upper lobe and bronchiectasis of right lower lobe with anomalous arterial supply of right lung from coeliac axis in this patient.

Influence of 4- and 6-color flow cytometers and acquisition/analysis softwares on the determination of lymphocyte subsets in HIV infection

BACKGROUND AND OBJECTIVES

Lymphocyte immunophenotyping provides valuable information for the diagnosis and monitoring of patients with cellular immunodeficiencies, such as HIV/AIDS. In this study, we have assessed the influence of 4-color and 6-color flow cytometers, and respective analytical softwares on the enumeration of lymphocytes in HIV infected individuals.

METHODS

The expression of various cell surface markers on lymphocytes was measured from the EDTA blood of 66 HIV infected patients on the FACSCalibur (4-color) and FACSCanto (6-color) flow cytometers. Percentage of lymphocytes expressing a particular cell surface marker was analyzed on FACSCalibur using the Cell Quest Pro software (v 5.2), while the analysis on FACSCanto was done using FACSCanto (v 1.0.3) and FACSDiva (v 4.1) softwares respectively.

RESULTS

The data shows significantly higher mean CD3 T-cell counts on FACSCalibur, Cell Quest Pro (1,864 +/- 1,044 cells/microl) as compared to FACSCanto (1,840 +/- 1,040 cells/microl) (P < 0.05). The CD4 T-cell counts were also higher on FACSCalibur, Cell Quest Pro (885 +/- 770 cells/microl), and FACSDiva (892 +/- 773 cells/microl) versus FACSCanto (867 +/- 767 cells/microl) (P < 0.05). FACSCalibur, Cell Quest Pro, and FACSDiva showed similar values except for CD8 T-lymphocytes where FACSDiva had significantly lower values (P < 0.05). The B-cell counts were unaffected when either of the instruments or softwares were used, while the natural killer (NK) cells (CD16 + 56 positive cells) showed similar trend like CD3 and CD4 counts with significant differences in the mean cell counts between FACSCalibur, Cell Quest Pro (240 +/- 165 cells/microl), and FACSDiva (238 +/- 163 cells/microl) versus FACSCanto with higher NK cell counts (260 +/- 176 cells/microl).

CONCLUSIONS

The enumeration of lymphocyte subsets was comparable between FACSCalibur, Cell Quest Pro, and FACSDiva, based analysis and it was significantly different than FACSCanto software based analysis. Our observations suggest that FACSDiva software should be preferred over the FACSCanto software for immunophenotyping on FACSCanto flow cytometer and the laboratories should report the instrument and software used for the specimen analysis while reporting immunophenotyping results.

Safety and efficacy of high-dose intravenous acyclovir in the management of neonatal herpes simplex virus infections

OBJECTIVE

The objective of this investigation was to establish the safety of high-dose (HD) acyclovir for the treatment of neonatal herpes simplex virus (HSV) disease. In addition, an estimate of therapeutic efficacy was sought, both with respect to mortality and to morbidity. Virologic efficacy of HD acyclovir was also assessed.

PARTICIPANTS

Infants who were </=28 days old and whose disease was considered to be caused by HSV were enrolled in this study. Patients with central nervous system (CNS; N = 28) or disseminated (N = 41) HSV infection were offered participation in the trial. A small number of patients with HSV disease limited to the skin, eyes, or mouth (SEM; N = 10) or whose disease was clinically consistent with HSV but who did not have virologic confirmation of infection (N = 9) also were enrolled on a compassionate basis. Only patients with virologically confirmed HSV disease were included in efficacy analyses. All enrolled patients were included in safety analyses.

METHODS

The study was an open-label evaluation of intravenous acyclovir at dosages higher than the 30 mg/kg/d standard dosage approved by the US Food and Drug Administration. The first 16 patients enrolled received intermediate-dose (ID) acyclovir (45 mg/kg/d), and the next 72 patients received HD acyclovir (60 mg/kg/d). Acyclovir was administered in 3 divided daily doses for 21 days. Neonates were assessed prospectively throughout treatment and at scheduled follow-up visits for the first 4 years of life. Data were compared with those of a previous National Institute of Allergy and Infectious Diseases Collaborative Antiviral Study Group trial in which patients received standard-dose (SD) acyclovir for 10 days and in which identical methods (with the exception of acyclovir dosage and duration of therapy) were used.

RESULTS

Six (21%) of 29 HD acyclovir recipients whose HSV disease remained localized to the SEM or CNS experienced neutropenia. One of the 6 had an absolute neutrophil count <500/mm(3), and 5 patients had an absolute neutrophil count (ANC) between 500/mm(3) and 1000/mm(3). In all 6 cases, the ANC recovered during continuation of acyclovir at the same dosage or after completion of acyclovir therapy, and there were no apparent adverse sequelae of the transient neutropenia. No other drug-related adverse events were reported among ID or HD recipients, and no other laboratory aberrations could be correlated specifically with antiviral therapy. The survival rate for the patients with disseminated HSV disease treated with HD acyclovir was significantly higher than for those in the previous study treated with SD acyclovir, with an odds ratio (OR) of 3.3 (95% confidence interval [CI]: 1.4-7.9). For patients with CNS disease, however, survival rates were similar for the HD and SD groups. To assess the effect of HD acyclovir on survival for the entire population with neonatal HSV disease, the Cox proportional hazards regression analysis was performed with stratification for disease category (CNS versus disseminated). In performing this analysis, differences in mortality for each disease category were weighted to allow statistical comparison of the treatment dosage groups (HD, ID, and SD). This analysis indicated that the survival rate for patients treated with HD acyclovir was statistically significantly higher than for patients treated with SD acyclovir (OR: 3.3; 95% CI: 1.5-7.3). Recipients of HD acyclovir had a borderline significant decrease in morbidity compared with SD recipients, after stratification for the extent of disease (SEM vs CNS vs disseminated) and controlling for the potential confounding factors of HSV type (HSV-1 vs. HSV-2), prematurity, and disease severity (seizures). Patients treated with HD acyclovir were 6.6 times (adjusted OR; 95% CI: 0.8-113.6) as likely to be developmentally normal at 12 months of age as patients treated with SD therapy.

CONCLUSION

These data support the use of a 21-day course of HD (60 mg/kg/d) intravenous acyclovir to treat neonatal CNS and disseminated HSV disease. Throughout the course of HD acyclovir therapy, serial ANC determination should be made at least twice weekly. Decreasing the acyclovir dosage or administering granulocyte colony-stimulating factor should be considered if the ANC remains below 500/mm(3) for a prolonged period.

Natural history of neonatal herpes simplex virus infections in the acyclovir era

OBJECTIVE

During the 2 decades in which effective antiviral therapies have been available for neonatal herpes simplex virus (HSV) disease, changes have been documented not only in the outcomes of infected infants, but also in the natural history of the disease itself. Numerous studies previously have reported that early institution of antiviral therapy is beneficial to the outcome of the disease. The objective of this study was to provide an update of neonatal HSV disease to identify means by which future improvements in the management of HSV-infected neonates can be made.

DESIGN/METHODS

Neonates enrolled in 2 studies of parenteral acyclovir for the treatment of neonatal HSV disease provided the data source. The National Institute of Allergy and Infectious Diseases Collaborative Antiviral Study Group conducted the studies between 1981 and 1997. A total of 186 patients are summarized, all of whom were treated with acyclovir. Demographic and clinical characteristics of these patients are reported.

RESULTS

Comparisons between patients treated in the periods between 1981-1988 and 1989-1997 according to extent of disease revealed that the mean time between the onset of disease symptoms and initiation of therapy has not changed significantly from the early 1980s to the late 1990s. Of all patients evaluated, 40% had fetal scalp monitors during the delivery process. A significant minority of patients did not have skin vesicles at the time of their presentation and did not develop them during the acute HSV disease (39% of patients with disseminated disease; 32% of patients with central nervous system [CNS] disease; and 17% of patients with skin, eye, and/or mouth disease). Among patients with CNS disease, mortality was associated with prematurity. Among patients with disseminated HSV disease treated with acyclovir at 30 mg/kg/d, mortality was associated with aspartate transaminase elevations of >/=10 times the upper limit of normal at the time of initiation of acyclovir therapy. Mortality was also associated with lethargy at initiation of antiviral therapy for patients with disseminated disease. Patients' morbidity status was associated with the extent of disease (skin, eye, and/or mouth disease vs CNS vs disseminated). For those patients with CNS disease, morbidity was also associated with seizures at initiation of antiviral therapy.

CONCLUSION

Data presented in the current comparison of neonatal HSV disease over the 2 periods (1981-1988 vs 1989-1997) demonstrate that no progress has been made in decreasing the interval between onset of HSV symptoms and initiation of antiviral therapy. Additional strides in the improvement of disease outcome may occur only if the interval between onset of symptoms and initiation of therapy is shortened. The means by which this will be accomplished lie in increased consideration of neonatal HSV infections in acutely ill infants. Specific data and recommendations to facilitate this goal are contained within.

Infection control programs at children's hospitals: a description of structures and processes

BACKGROUND

Infection control (IC) structures and processes determine the effectiveness of surveillance efforts to prevent infections in health care settings.

METHODS

A survey was sent to 56 children's hospitals collaborating in the Pediatric Prevention Network (PPN).

RESULTS

Completed surveys were returned from 48 hospitals. Responsibility for the IC program resided with the medical director (21%); vice president for patient care (18%); quality improvement director (17%); other senior hospital administrator (15%); or other hospital personnel (18%). Forty-two hospitals had an IC committee; 32 had antimicrobial restriction/control policies; and 21 had an antimicrobial restriction/control task force or committee. Components of antimicrobial restriction programs included infectious disease specialist approval, restricted formularies, selective susceptibility test reporting, and staff education programs. Many methods were used to detect infections, including microbiology laboratory reports (100%); record reviews (98%); informal reports from providers (90%); and readmission reviews (77%).

CONCLUSIONS

Children's hospitals vary widely in how they design and implement their IC functions. These variations influence adverse event detection and nosocomial infection rate calculations. If medical errors, including nosocomial infections, are to be detected and hospital rates compared, standardized methods to collect, analyze, and report data are needed. The PPN has initiated activities to standardize surveillance and IC practices in participating hospitals.

Pediatric Prevention Network: a multicenter collaboration to improve health care outcomes

Nosocomial infections and antimicrobial resistance are major causes of mortality and morbidity and have become a major public health focus. To date, most national and international nosocomial infection surveillance and prevention activities have been focused on adults, despite the fact that pediatric patients are at high risk for nosocomial infections because of their immature immune systems and prevalent device usage. In 1997 the Hospital Infections Program at the Centers for Disease Control and Prevention and the National Association of Children's Hospitals and Related Institutions partnered to establish a Pediatric Prevention Network. Infection control professionals and their hospital administrators at all children's hospitals were invited to participate. The objectives of the network are to establish baseline infection rates; design, implement, and evaluate prevention interventions; establish benchmark rates and best practices; and serve as a site for multicenter studies to improve outcomes for hospitalized children. This network serves as a model for quality improvement systems in health care.

Complications of outpatient parenteral antibiotic therapy in childhood

Complications in children receiving outpatient parenteral antibiotic therapy were reviewed. Catheter-associated complications and/or adverse drug reactions occurred in 50% of courses. Most complications were minor, and almost all infections were successfully treated. Even with early discontinuation of parenteral antibiotics because of adverse drug reactions in 24% of the courses, the outcome was excellent.

Recombinant CD4-IgG2 in human immunodeficiency virus type 1-infected children: phase 1/2 study. The Pediatric AIDS Clinical Trials Group Protocol 351 Study Team

The use of recombinant CD4-IgG2 in pediatric human immunodeficiency virus type 1 (HIV-1) infection was evaluated by single and multidose intravenous infusions in 18 children in a phase 1/2 study. The study drug was well tolerated, and dose proportionality was observed in terms of area under time-concentration curve and peak serum concentration. Acute decreases of >0.7 log(10) copies/mL in serum HIV-1 RNA concentration were seen in 4 of the 6 children treated with 4 weekly 10 mg/kg doses. At 14 days after treatment, 3 children had sustained reductions in serum HIV-1 RNA; the other children had rebounded to baseline levels or above. By 28 days after therapy, the peak HIV-1 cellular infectious units was reduced in all 6 children, including the 2 who had experienced an earlier transient increase in values. Thus, recombinant CD4-IgG2 treatment of HIV-1-infected children appears to be well tolerated and capable of reducing HIV-1 burden.

Nucleoside analogs plus ritonavir in stable antiretroviral therapy-experienced HIV-infected children: a randomized controlled trial. Pediatric AIDS Clinical Trials Group 338 Study Team

CONTEXT

Although protease inhibitors are used routinely in adults with human immunodeficiency virus (HIV) infection, the role of these drugs in the treatment of clinically stable HIV-infected children is not clear.

OBJECTIVE

To evaluate the safety, tolerance, and virologic response produced by a change in antiretroviral therapy in HIV-infected children who were clinically and immunologically stable while receiving previous therapy.

DESIGN

The Pediatric AIDS Clinical Trials Group 338, a multicenter, phase 2, randomized, open-label controlled trial conducted from February 6 to April 30, 1997 (patient entry period); patients were followed up for 48 weeks.

SETTING

Pediatric HIV research clinics in the United States and Puerto Rico.

PATIENTS

Two hundred ninety-seven antiretroviral-experienced, protease inhibitor-naive, clinically stable HIV-infected children aged 2 to 17 years.

INTERVENTIONS

Children were randomized to receive zidovudine, 160 mg/m2 3 times per day, plus lamivudine, 4 mg/kg 2 times per day (n = 100); the same regimen plus ritonavir, 350 mg/m2 2 times per day (n = 100); or ritonavir, 350 mg/m2 2 times per day, and stavudine, 4 mg/kg 2 times per day (n = 97).

MAIN OUTCOME MEASURE

Plasma HIV-1 RNA levels at study weeks 12 and 48, compared among the 3 treatment groups.

RESULTS

At study week 12, 12% of patients in the zidovudine-lamivudine group had undetectable plasma HIV RNA levels (<400 copies/mL) compared with 52% and 54% of patients in the 2- and 3-drug ritonavir-containing groups, respectively (P<.001). Through study week 48, 70% of children continued receiving their ritonavir-containing regimen. At study week 48, 42% of children receiving ritonavir plus 2 nucleosides compared with 27% of those receiving ritonavir and a single nucleoside had undetectable HIV RNA levels (P = .04); however, similar proportions in each group continuing initial therapy had HIV RNA levels of less than 10000 copies/mL (58% vs 48%, respectively; P = .19).

CONCLUSIONS

In our study, change in antiretroviral therapy to a ritonavir-containing regimen was associated with superior virologic response at study week 12 compared with change to a dual nucleoside analog regimen. More children receiving ritonavir in combination with 2 compared with 1 nucleoside analog had undetectable HIV RNA levels at study week 48.

Antibiotic prophylaxis after basilar skull fractures: a meta-analysis

Antibiotic prophylaxis after basilar skull fractures remains controversial. Previous studies have not clearly delineated the utility of prophylactic antibiotics in this setting. We undertook this study to determine if antibiotic prophylaxis after basilar skull fractures prevented meningitis. We performed a formal systematic review of previously published studies after a computerized search with use of the MEDLINE data base (1970-1996). Fourteen studies were identified, and 12 studies met the criteria for inclusion. Study design and quality were assessed by two independent investigators with use of a predetermined protocol. A total of 1,241 patients with basilar skull fractures were included; 719 patients received antibiotics, and 522 patients did not receive antibiotics. Overall results suggest that antibiotic prophylaxis did not prevent meningitis among patients with basilar skull fractures (odds ratio [OR] = 1.15; 95% confidence interval [CI] = 0.68-1.94; P = .678). Patients with basilar skull fractures and cerebrospinal fluid leakage were analyzed separately (OR = 1.34; 95% CI = 0.75-2.41; P = .358), as were children (OR = 1.04; 95% CI = 0.07-14.90; P = 1.000). Antibiotic prophylaxis after basilar skull fractures does not appear to decrease the risk of meningitis.

Chromobacterium violaceum infection

Chromobacterium violaceum infection is confined to the tropical and subtropical areas, with almost all reported cases occurring in the Southeast. The most common feature of this infection is sepsis, followed by cutaneous involvement and liver abscesses. Treatment consists of surgical drainage of purulent collections and appropriate antimicrobial therapy, such as chloramphenicol, gentamicin, imipenem, trimethoprim-sulfamethoxazole, or ciprofloxacin. Although C violaceum infection is rare, it is potentially fatal and remains an important entity for clinicians to suspect and treat appropriately.

The role of ethylene oxide allergy in sterile shunt malfunctions

Failure of an intact ventriculoperitoneal shunt, in the absence of an overt infection, is often due to its occlusion by cellular debris and/or an abdominal pseudocyst. This failure is thought to be caused by an infection by an organism which is difficult to culture or by some poorly defined allergic response to the shunt materials. Little attention has been directed to the treatment that the shunts receive prior to implantation: specifically, their exposure to ethylene oxide as a means of sterilization. We have found ethylene oxide metabolites in the spinal fluid of children with shunt malfunction months after their systems were implanted. Many of these patients had coincident CSF eosinophilia. In addition, two of the children had detectable serum IgE antibody directed against an albumin-ethylene oxide conjugated protein. Both of these children had several shunt malfunctions within a short period, yet neither child could be shown to have a shunt infection despite multiple cultures. We therefore suggest that in some patients proteins altered by ethylene oxide incite an IgE mediated response which may lead to shunt malfunction.