Prophylaxis against respiratory syncytial virus in premature infants. IMpact-RSV Study Group.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to E M Connor.
Explore the source record for details and available documents.
This phase I clinical trial was designed to determine the feasibility of using rBCG as a live bacterial vaccine vector for the outer surface protein A (OspA) of Borrelia burgdorferi and as model for other vaccines based on a rBCG vector. To construct the vaccine, a signal peptide derived from a mycobacterial lipoprotein was used to direct the export, and membrane-associated surface expression, of OspA in a standard strain of BCG (Connaught). The rBCG OspA vaccine was safe and immunogenic in several animal species, and protective in a mouse model of Lyme borreliosis. An intradermal injection (0.1 ml) of rBCG OspA was administered to 24 healthy adult volunteers sequentially at one of four dose levels, ranging from 2.0 x 10(4) CFU to 2 x 10(7) CFU, using a dose-escalation design. All volunteers were initially PPD-skin test and OspA antibody negative, and they were monitored for 2 years after immunization. Three volunteers had mild flu-like reactions 1-2 days after vaccination. Local ulceration and drainage at the site of injection, which occurred in 50% and 83% of volunteers in the two highest dose groups, persisted for 1-70 days before the ulcers healed. Most of the drainage samples yielded rBCG colonies that contained the OspA plasmid. Thirteen of 24 vaccinees, principally in the two highest dose groups, converted their PPD skin tests from negative to positive. None of the 24 volunteers developed OspA antibody. In conclusion, the current rBCG vaccine construct, the first such construct tested in humans, had a safety profile comparable to that of licensed BCG, but it did not elicit primary humoral responses to the vectored antigen.
The objective of this study was to quantify, in vivo, constitutive and tumor necrosis factor alpha (TNF-alpha)-enhanced expression of mucosal addressin cell adhesion molecule-1 (MAdCAM-1) in different tissues from healthy wild-type mice (C57BL/6) as well as interleukin-10 (IL-10)-deficient mice with and without active colitis. Using the dual radiolabel monoclonal antibody technique, we found substantial constitutive expression of MAdCAM-1 in the intestine, colon, and mesenteric lymph nodes. MAdCAM-1 expression in these tissues was significantly enhanced, in a time-dependent manner, by systemic administration of TNF-alpha. Maximum surface expression was observed at 18 h after TNF-alpha administration and remained significantly elevated at 48 h post-TNF-alpha injection. No significant constitutive nor TNF-alpha-induced expression of MAdCAM-1 was detected in skeletal muscle, brain, or heart. In IL-10-deficient (IL-10 k/o) mice with no clinical or histological evidence of colitis, constitutive and TNF-alpha-induced expression of MAdCAM-1 in the intestine, cecum, and colon was not different from those values obtained with healthy wild-type controls. IL-10-deficient mice with active colitis exhibited a four- to fivefold greater expression of MAdCAM-1 in the cecum and colon compared with their healthy controls or to IL-10 k/o mice with no evidence of colitis. Taken together, these data demonstrate that TNF-alpha enhances surface expression of MAdCAM-1 in intestinal and colonic tissues to the same extent in both wild-type and IL-10 k/o mice with no colonic inflammation, whereas IL-10 k/o mice with active colitis exhibited a profound up-regulation of MAdCAM-1 in the colon.
Serial samples from human immunodeficiency virus-infected infants in the first year of life were analyzed by quantitative human immunodeficiency virus polymerase chain reaction assays. Very high, persistent levels of plasma RNA and proviral DNA were detected throughout the study period, suggesting the absence of an effective immune response. Most patients had normal CD4 lymphocyte counts and were symptom free for the first 3 to 6 months despite high levels of viral replication. These findings support the evaluation of early intervention (before symptoms develop) and efforts to establish the predictive value of these assays.
Explore the source record for details and available documents.
BACKGROUND AND METHODS: Maternal-infant transmission is the primary means by which young children become infected with human immunodeficiency virus type 1 (HIV). We conducted a randomized, double-blind, placebo-controlled trial of the efficacy and safety of zidovudine in reducing the risk of maternal-infant HIV transmission. HIV-infected pregnant women (14 to 34 weeks' gestation) with CD4+ T-lymphocyte counts above 200 cells per cubic millimeter who had not received antiretroviral therapy during the current pregnancy were enrolled. The zidovudine regimen included antepartum zidovudine (100 mg orally five times daily), intrapartum zidovudine (2 mg per kilogram of body weight given intravenously over one hour, then 1 mg per kilogram per hour until delivery), and zidovudine for the newborn (2 mg per kilogram orally every six hours for six weeks). Infants with at least one positive HIV culture of peripheral-blood mononuclear cells were classified as HIV-infected. RESULTS: From April 1991 through December 20, 1993, the cutoff date for the first interim analysis of efficacy, 477 pregnant women were enrolled; during the study period, 409 gave birth to 415 live-born infants. HIV-infection status was known for 363 births (180 in the zidovudine group and 183 in the placebo group). Thirteen infants in the zidovudine group and 40 in the placebo group were HIV-infected. The proportions infected at 18 months, as estimated by the Kaplan-Meier method, were 8.3 percent (95 percent confidence interval, 3.9 to 12.8 percent) in the zidovudine group and 25.5 percent (95 percent confidence interval, 18.4 to 32.5 percent) in the placebo group. This corresponds to a 67.5 percent (95 percent confidence interval, 40.7 to 82.1 percent) relative reduction in the risk of HIV transmission (Z = 4.03, P = 0.00006). Minimal short-term toxic effects were observed. The level of hemoglobin at birth in the infants in the zidovudine group was significantly lower than that in the infants in the placebo group. By 12 weeks of age, hemoglobin values in the two groups were similar. CONCLUSIONS: In pregnant women with mildly symptomatic HIV disease and no prior treatment with antiretroviral drugs during the pregnancy, a regimen consisting of zidovudine given ante partum and intra partum to the mother and to the newborn for six weeks reduced the risk of maternal-infant HIV transmission by approximately two thirds.
BACKGROUND: Serious bacterial infections are common in children infected with the human immunodeficiency virus (HIV). Studies performed before zidovudine became standard therapy found that intravenous immune globulin decreases the number of serious bacterial infections in these children. We designed a multicenter study to evaluate the efficacy of intravenous immune globulin in children with advanced HIV infection who were receiving zidovudine. METHODS: In a double-blind trial 255 children between 3 months and 12 years of age who had the acquired immunodeficiency syndrome (AIDS) or AIDS-related complex were randomly assigned to receive either intravenous immune globulin (400 mg per kilogram of body weight) (n = 129) or placebo (0.1 percent albumin) (n = 126) every 28 days. All children received 180 mg of zidovudine per square meter of body-surface area orally four times daily. Treatment assignment was stratified according to whether the patients had a history of one or more serious bacterial infections, had previously been treated with zidovudine, or were currently receiving prophylaxis with trimethoprim-sulfamethoxazole. The median length of follow-up was 30.6 months. RESULTS: The estimated two-year rates of serious bacterial infections with confirmed pathogens were 16.9 percent for the immune globulin group and 24.3 percent for the placebo group (relative risk, 0.60; 95 percent confidence interval, 0.35 to 1.04; P = 0.07). The treatment effect was seen primarily among the 174 children who were not receiving trimethoprim-sulfamethoxazole prophylaxis at entry; the estimated two-year rates of infection were 11.3 percent for the immune globulin group and 26.8 percent for the placebo group (relative risk, 0.45; 95 percent confidence interval, 0.22 to 0.91; P = 0.03). For the 81 children who were receiving trimethoprim-sulfamethoxazole prophylaxis initially, the rates were 27.7 percent in the immune globulin group and 17.7 percent in the placebo group (relative risk, 1.26; 95 percent confidence interval, 0.44 to 3.66; P = 0.67). The two-year survival was similar in the two groups: 79.2 percent among immune globulin recipients and 75.4 percent among placebo recipients (P = 0.41). CONCLUSIONS: In children with advanced HIV disease who are receiving zidovudine, intravenous immune globulin decreases the risk of serious bacterial infections. However, this benefit is apparent only in children who are not receiving trimethoprim-sulfamethoxazole as prophylaxis.
Essentially all new cases of human immunodeficiency virus (HIV) infection in infants and young children occur as a consequence of exposure to HIV either in utero, intrapartum or postpartum during breast feeding. Currently it is estimated that the majority of vertical transmission of HIV occurs at or near the time of birth. Based on what is known about the biology of perinatal HIV transmission, the HIV burden of the mother, effectiveness of her immune response and that of her fetus/infant and the integrity of the placental "barrier" are likely to play important roles in this process. The role of impaired immunologic control of HIV is gaining recognition as a potential key element in the pathophysiology of perinatal HIV transmission. In most studies to date, advanced maternal disease and low CD4 lymphocyte count have been associated with increased risk of vertical HIV transmission. In addition some studies have indicated that low maternal titers of antibodies to certain V3 loop epitopes may have a similar effect on vertical transmission. Cellular immune responses, which are known to play an important role in host defense against HIV, appear to be impaired in infants after exposure to HIV, especially those responses involving the development of cytotoxic lymphocytes. Mounting evidence suggests that enhancement of humoral and/or cellular immune responses in pregnant women and exposed infants is a logical and potentially feasible approach to interruption of perinatal transmission (an approach similar to that utilized for perinatally acquired hepatitis B virus infection). Studies are now in progress to assess HIV hyperimmune globulin and envelope HIV vaccines in pregnant woman and HIV-exposed infants.
BACKGROUND AND METHODS: Zidovudine has been shown to be an effective antiretroviral treatment in adults with human immunodeficiency virus (HIV) infection. We examined the safety of zidovudine and the tolerance of and therapeutic response to the drug in 88 children with advanced HIV disease. During a 24-week outpatient trial, zidovudine (180 mg per square meter of body-surface area per dose) was given by mouth every six hours and serial measurements were made of clinical, immunologic, and virologic indexes. Children who completed 24 weeks of treatment were permitted to continue receiving zidovudine. RESULTS: Of the 88 children (mean age, 3.9 years; range, 4 months to 11 years), 61 completed the initial 24-week trial, and 49 continued to receive zidovudine for up to 90 weeks (median follow-up, 56 weeks). The patients generally tolerated zidovudine well. One or more episodes of hematologic toxicity occurred in 54 children (61 percent)--anemia (hemoglobin level, less than 75 g per liter) in 23 children (26 percent) and neutropenia (neutrophil count, less than 0.75 x 10(9) per liter) in 42 (48 percent). Many of these abnormalities resolved spontaneously, but 30 children required transfusions or a modification of the dose of zidovudine. Only three children had to stop receiving the drug because of hematologic toxicity. Kaplan-Meier analysis demonstrated that the probability of survival was 0.89 after 24 weeks and 0.79 after 52 weeks. There was marked improvement in weight gain, cognitive function (mainly in children less than 3 years old), serum and cerebrospinal fluid concentrations of p24 antigen, and the proportion of cerebrospinal fluid cultures negative for HIV. CD4+ lymphocyte counts (mean at base line, 0.263 x 10(9) per liter) improved during the first 12 weeks, although the improvement was not sustained through the 24th week. CONCLUSIONS: Zidovudine in a dose of 180 mg per square meter every six hours can be safely administered to children with advanced HIV disease. The resultant clinical, immunologic, and virologic improvements in children are similar to those reported with zidovudine in adults.
The lesions observed in biopsy and autopsy material from children with the acquired immunodeficiency syndrome (AIDS) can be divided into three pathogenetic categories: primary lesions related to infection by human immunodeficiency virus (HIV) (e.g., lymphoreticular system and brain); lesions due to the sequelae of HIV infection (e.g., opportunistic infections, pulmonary lymphoid lesions, etc.); and lesions of undetermined pathogenesis (e.g., renal lesions, cardiomyopathy, etc.). The role of morphologic studies in AIDS in understanding the pathogenesis of the various lesions and their clinical implications are discussed by describing the following examples among others. Study of the thymus enabled us to distinguish AIDS from some congenital immune deficiency syndromes. Thymic injury contributes to immunodeficiency in AIDS. Its apparent irreversibility will have to be considered in the long-term management of children with AIDS when specific effective therapy for HIV becomes available. Demonstration of HIV--like particles in the characteristic giant cells in the brain has been instrumental in the recognition of HIV encephalopathy. Biopsy is helpful in the rapid diagnosis of opportunistic infections (OIs). Autopsy study of OIs has shown involvement of clinically unsuspected organs, such as the adrenals. Characterization of the pulmonary lymphoid lesions led to their inclusion as a diagnostic criterion for AIDS in children. Progression of pulmonary lymphoid lesions to a lymphoproliferative disorder was demonstrated at autopsy. Recognition of lesions such as cardiomyopathy and arteriopathy at autopsy should alert clinicians to suspect these disorders during life.
Explore the source record for details and available documents.
The cytokine tumor necrosis factor (TNF) was assayed in the sera (n = 31) and cerebrospinal fluid (n = 26) of children with acquired immunodeficiency syndrome, using a competitive radioimmunoassay. Elevated serum levels of TNF were found in 15 (79%) of 19 patients with progressive encephalopathy (PE), compared with 1 (8%) of 12 patients without neurologic involvement. There was a significant association of PE with elevated serum TNF levels. Conversely, of 16 patients with elevated serum TNF levels, 15 (94%) were found to have PE, and of 8 patients with serum TNF levels greater than 100 pg/ml, all 8 (100%) had PE. No association was found between cerebrospinal fluid levels of TNF and PE. Neither serum nor cerebrospinal fluid TNF levels correlated with the degree of cachexia. These data suggest that circulating TNF may be responsible for the myelin damage that occurs in human immunodeficiency virus type 1-associated PE.
Six children died of acquired immunodeficiency syndrome (AIDS), four of them females, ages 7 months, 13 months, 2 years 8 months, and 4 years; and two of them males, aged 2 1/2 and 7 years. They were born to IV drug-addicted parents. The conduction system (CS) and the entire heart were studied by serial section. In all cases the heart was hypertrophied and enlarged; one had total thrombotic occlusion of the right coronary artery with extensive infarction of the ventricular septum. Vascular changes also were found in all hearts, involving small arteries, arterioles, and venules. In the arteries, they involved the intima, media, and adventitia, and perivascular areas in a degenerative and inflammatory process. The elastic tissue was especially affected. A nonspecific myocarditis was present in four cases and epicarditis in all. Changes in the summit of the ventricular septum were present in four cases, consisting of increased fibrosis and arteriolosclerosis. The CS changes varied in location, showing either vasculitis, myocarditis, or fragmentation of the bundle with lobulation and fibrosis. The changes in the conduction system were not as severe as the changes in the surrounding myocardium. In one case the ECG was abnormal, showing left hemiblock. This corresponded to the finding of fibrosis, vacuolization of cells, and space formation in the left bundle branch.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
In a longitudinal study, human immunodeficiency virus type 1 (HIV-1) antigen (HIV-Ag) was measured in serum specimens from 54 children with HIV-1 infection followed for a median duration of 17 months. The persistent detection of free HIV-Ag in a group of 25 children was associated with clinical deterioration in 22 (88%) and a mortality of 52%, whereas the persistent nondetection of free HIV-Ag in a group of 18 children was associated with clinical deterioration in five (28%) and a mortality of 11% during the period of observation. Nine children had transient HIV-1 antigenemia and two children converted from HIV-Ag negative to positive during the study. Free HIV-Ag levels varied inversely with antibody reactivity to viral core proteins p24 and p17 determined by Western immunoblot, suggesting either the formation of immune complexes or a balance between viral expression and the host immune response. Five mother-infant pairs were studied for HIV-Ag expression in the perinatal period. In three of these pairs, both mother and infant were HIV-Ag negative, in one pair the mother had high levels of HIV-Ag and the infant was HIV-Ag negative. In the remaining mother-infant pair, the neonate became HIV-Ag positive but the mother was HIV-Ag negative prepartum and postpartum. These data suggest that HIV-Ag probably does not cross the placenta and that the detection of free HIV-Ag in the offspring of a HIV-1 infected mother most likely indicates viral infection.(ABSTRACT TRUNCATED AT 250 WORDS)
Three children with acquired immunodeficiency syndrome and primary lymphoma of the CNS are described. All three children had clinical signs of focal mass lesions and progressive neurologic deficits. In one child the deterioration was extremely rapid. New lesions appeared on serial CT scans every few days, simulating an infectious process and leading to death within 3 weeks. Results of neuroradiologic studies in these patients demonstrated multicentric lesions that were often periventricular. On CT scans, the lesions were hyperdense before contrast and were enhanced with contrast medium. Double-dose delayed contrast CT scans and magnetic resonance imaging studies were more sensitive in indicating additional lesions. Histologically, all three tumors were B cell neoplasms; two lymphomas were large cell type, whereas one was small cell, noncleaved (Burkitt-like). Primary CNS lymphoma occurred with an incidence of 1/26 (4%) in our autopsy series and 3/100 (3%) of all pediatric cases of human immunodeficiency virus-type 1 infection, living and dead, that have been seen at the Children's Hospital of New Jersey. By comparison, opportunistic and reactivated latent CNS infections were less common in this same population and never appeared clinically as mass lesions. Therefore, in our experience, primary lymphoma is the most common cause of focal or multifocal mass lesions in the brains of children with acquired immunodeficiency syndrome. This tumor may be radiosensitive. In most cases, early biopsy is probably necessary to establish the diagnosis.
The retrovirus that causes acquired immune deficiency syndrome (AIDS) is now designated the human immunodeficiency virus (HIV). The cerebrospinal fluid (CSF) of 27 children with HIV infection was assayed for intra-blood-brain barrier (IBBB) synthesis of HIV-specific antibodies and for the presence of HIV antigen. In this cohort, 11 children had a progressive encephalopathy (PE), 9 had a static encephalopathy (SE), and 7 had normal neurological findings (N). IBBB synthesis of HIV-specific antibodies was identified (using matched serum and CSF specimens) in 7 of 11 children with PE, 4 of 9 children with SE, and 2 of 7 children with N. HIV antigen was found (using a highly sensitive solid-phase enzyme immunoassay) in the CSF of 8 of 11 children with PE, none of the children with SE, and none of the 7 children with N. On the basis of these data, we conclude that: IBBB synthesis of HIV antibodies indicates invasion of the central nervous system but may reflect prior or current infection; and HIV antigen in CSF indicates viral expression and correlates with the occurrence of PE. These findings strongly implicate HIV as the causative agent of PE in these children. The assay for HIV antigen in the CSF may be of value in determining the prognosis of children with HIV infection and for evaluating the efficacy of therapeutic agents against this retrovirus.