Arye Rubinstein

MOTHER-TO-INFANT TRANSMISSION OF HUMAN IMMUNODEFICIENCY VIRUS TYPE 1: ASSOCIATION WITH PREMATURITY OR LOW ANTI-gp120

In a prospective study of pregnant women infected with human immunodeficiency virus type 1 (HIV-1) in Brooklyn, New York, USA, 16 (29%) of 55 evaluable infants were infected with HIV-1. 9 infants had paediatric acquired immunodeficiency syndrome, 6 had less severe clinical manifestations of HIV-1 infection, and 1 was symptom-free but was seropositive for HIV-1 beyond 15 months of age. The 10 infants born at 37 weeks of gestation or earlier were at higher risk of HIV-1 infection than infants born at 38 weeks of gestation or later (60% vs 22%) but the median age at appearance of disease was approximately 5 months in both groups. The HIV-1 transmission rate was not associated with predelivery levels of maternal T cells, anti-p24, or neutralising antibodies but it was higher, among full-term infants, for those with mothers in the lowest third of the distribution of anti-gp120 levels (53%). On immunoblot, transmitting mothers lacked a gp120 band but not other bands. Protection was not associated with antibody to recombinant peptides from the hypervariable region of the major neutralising gp120 epitope, and the anti-gp120 endpoint dilution titre was similar in transmitting and non-transmitting mothers. Mothers of uninfected full-term infants appear to confer immunological protection against HIV-1 infection of their offspring by way of a high-affinity antibody to a gp120 epitope, whose specificity has importance for vaccine development and possibly perinatal immunotherapy.

Defective humoral immunity in pediatric acquired immune deficiency syndrome

Specific antibody production was assessed in six young children with the acquired immune deficiency syndrome (AIDS). All patients were immunized with bacteriophage phi X 174, a T cell-dependent neoantigen. In addition, antibody responses to pneumococcal vaccine and tetanus toxoid, lymphocyte responses to mitogens, and serum immunoglobulin levels were determined. Polyclonal hypergammaglobulinemia was documented in three patients. Responses to bacteriophage phi X 174 were abnormal in all patients: primary responses were blunted, secondary responses were markedly decreased, and the class switch (IgM-IgG) was absent in five of six patients. Antibody formation to pneumococcal vaccine and tetanus toxoid was also diminished. Lymphocyte mitogenic responses to phytohemagglutinin, concanavalin A, pokeweed mitogen, and staphylococcal Cowan A were generally decreased. These findings confirm that pediatric patients with AIDS have significant abnormalities in humoral immunity. Dysfunction of both T cells and B cells plays a role in the resultant poor specific antibody production.

Pulmonary disease in children with acquired immune deficiency syndrome and AIDS-related complex

Two major pulmonary diseases were defined on the basis of lung biopsies in 15 children with acquired immune deficiency syndrome (AIDS) or AIDS-related complex. Pneumocystis carinii pneumonia was observed in eight children, and pulmonary lymphoid hyperplasia in six. One child had nonspecific interstitial pneumonitis. Children with P. carinii pneumonia had more severe hypoxemia, with higher alveolar-arterial oxygen gradients, and higher isomorphic elevations of serum lactate dehydrogenase. Clinically, children with pulmonary lymphoid hyperplasia were older, and had digital clubbing, parotid gland enlargement, and elevated serum IgG levels. Results of serologic assays and lung tissue analysis were suggestive of persistent Epstein-Barr virus infection exclusively in patients with pulmonary lymphoid hyperplasia. Recognition of the clinical and laboratory findings characteristic of each entity may assist in the differential diagnosis without the need of surgical biopsy.

AIDS Calcification of the basal ganglia in infants and children

CT or postmortem examination demonstrated calcification of the basal ganglia in eight infants and children with acquired immune deficiency syndrome. Serial CT studies documented progression of both bilateral symmetric calcium densities and cerebral atrophy. Clinical features included progressive encephalopathy with dementia, and pyramidal tract signs. Postmortem examination of four children revealed variable degrees of calcific vasopathy of the basal ganglia, involving predominantly the putamen and globus pallidus.

Bacterial infection in the acquired immunodeficiency syndrome of children

We have followed 46 children with acquired immunodeficiency syndrome and acquired immunodeficiency syndrome-related complex. Twenty-six patients had at least one episode of serious bacterial infection. Twenty-seven episodes of sepsis were documented in 21 patients. Soft tissue infection was common in both the presence and the absence of documented bacteremia. Urinary tract infection commonly presented as worsening diarrhea in the absence of sepsis. Organisms commonly isolated included Streptococcus pneumoniae, Haemophilus influenzae and Salmonella sp. Staphylococcal infection accompanied episodes of cellulitis/abscess. Escherichia coli commonly caused urinary tract infection in the absence of sepsis. Enteric and nosocomial sepsis was limited to hospitalized, instrumented patients or to individuals who had received prior antibiotic therapy as outpatients. We conclude that bacterial infection causes serious morbidity in acquired immunodeficiency syndrome and acquired immunodeficiency syndrome-related complex and may be further evidence for altered humoral immunity in the disorder.

DEVELOPMENTAL ABNORMALITIES IN INFANTS AND CHILDREN WITH ACQUIRED IMMUNE DEFICIENCY SYNDROME (AIDS) AND AIDS‐RELATED COMPLEX

Children with acquired immune deficiency syndrome (AIDS) display two types of clinical picture: (1) a fullblown AIDS characterized by the presence of opportunistic infections and/or Kaposis sarcoma and (2) a prodromal stage now identified as AIDS‐related complex (ARC). Neurological complications have been identified in infants and children with the disease. This paper discusses the developmental abnormalities in 16 pediatric patients, seven with AIDS and nine with ARC, ranging in age from six months to six years. In all cases, the mothers of these children either had ARC, AIDS and/or used intravenous drugs. Developmental histories showed delayed acquisition of milestones in most children following the diagnosis of AIDS or ARC, with delayed motor milestones consistently noted in both groups. Several children with AIDS actually lost milestones as their illness progressed; this has not occurred in the ARC group. Psychometric testing revealed more severe cognitive dysfunction in the group with AIDS. Involvement of the central nervous system was documented clinically, radiologically, and/or electrophysiologically in all patients with AIDS. In the ARC group the course of the illness has shown greater variability. Medical and social factors that may contribute to the developmental abnormalities are discussed.

Enhancement of HIV-1 infection by the capsular polysaccharide of Cryptococcus neoformans

Patients with AIDS who become infected with Cryptococcus neoformans have a poor prognosis. We speculated that the presence of cryptococcal capsular polysaccharide may enhance HIV-1 infection. In an in-vitro study, the presence of cryptococcal polysaccharide significantly increased (p less than 0.05) production of p24 antigen after infection of H9 cells with HIV-1-infected H9 cells. We also found similar results when lymphocytes from an HIV-1-infected patient were co-cultured with mononuclear cells from an uninfected individual. Our findings suggest a new pathogenic role for the capsular polysaccharide--namely, the capacity to enhance HIV-1 infectivity.

Vertical transmission of human immunodeficiency virus (HIV) infection. Reactivity of maternal sera with glycoprotein 120 and 41 peptides from HIV type 1.

The observation that approximately 70% of HIV-infected pregnant women do not transmit infection vertically suggests that antibody therapy may be effective in the prevention of transmission of HIV infection from mother to child. Currently, there is an incomplete understanding of the processes involved in vertical transmission of HIV infection. The elucidation of the serological basis of maternal immunity as it relates to protection from vertical transmission is the goal of this study. We have screened 20 maternal sera from HIV+ individuals of known vertical transmission status for reactivity with 31 peptides spanning the entire envelope glycoprotein of HIV-1. Of interest was reactivity to regions outside of the V3 loop of gp120. The findings have been examined in relationship to transmission status, as well as to in vitro anti-HIV-1 biological activity. Our results indicate that lack of vertical transmission is correlated with high viral neutralization activity, but not with antisyncytial activity nor with binding to the V3 peptides examined in this study. Also, the transmission group bound to fewer gp41 peptides when compared with the nontransmission group, suggesting that immune responses to gp41 may be important in preventing transmission. These findings may provide insights into the design of passive immunotherapies.

Plasma deoxyadenosine, adenosine, and erythrocyte deoxyATP are elevated at birth in an adenosine deaminase-deficient child.

We have determined concentrations of adenosine, deoxyadenosine, and deoxyATP (dATP) in cord blood from an infant prenatally diagnosed as ADA deficient. Plasma deoxyadenosine and adenosine were already elevated in cord blood (0.7 and 0.5 microM vs. normal of less than 0.07 microM). Elevation of plasma deoxyadenosine has not previously been documented in these children. Erythrocyte dATP content was also elevated at birth (215 nmol/ml packed erythrocytes vs. normal of 2.9). These elevated concentrations of adenosine, deoxyadenosine, and dATP are similar to those we observed in another older adenosine deaminase-deficient patient and may explain the impaired immune function and lymphopenia seen at birth.

Obesity-Associated Asthma in Children: A Distinct Entity

BACKGROUND Obesity-associated asthma has been proposed to be a distinct entity, differing in immune pathogenesis from atopic asthma. Both obesity-mediated inflammation and increase in adiposity are potential mechanistic factors that are poorly defined among children. We hypothesized that pediatric obesity-associated asthma would be characterized by T helper (Th) 1, rather than the Th2 polarization associated with atopic asthma. Moreover, we speculated that Th1 biomarkers and anthropometric measures would correlate with pulmonary function tests (PFTs) in obese asthmatic children. METHODS We recruited 120 children, with 30 in each of the four study groups: obese asthmatic children, nonobese asthmatic children, obese nonasthmatic children, and nonobese nonasthmatic children. All children underwent pulmonary function testing. Blood was collected for measurement of serum cytokines. T-cell responses to mitogen, phorbol 12-myristate 13-acetate (PMA), or antigens tetanus toxoid or Dermatophagoides farinae were obtained by flow cytometric analysis of intracellular cytokine staining for interferon-γ (IFN-γ) (Th1) or IL-4 (Th2) within the CD4 population. RESULTS Obese asthmatic children had significantly higher Th1 responses to PMA (P < .01) and tetanus toxoid (P < .05) and lower Th2 responses to PMA (P < .05) and D farinae (P < .01) compared with nonobese asthmatic children. Th-cell patterns did not differ between obese asthmatic children and obese nonasthmatic children. Obese asthmatic children had lower FEV(1)/FVC (P < .01) and residual volume/total lung capacity ratios (P < .005) compared with the other study groups, which negatively correlated with serum interferon-inducible protein 10 and IFN-γ levels, respectively. PFTs, however, did not correlate with BMI z score or waist to hip ratio. CONCLUSIONS We found that pediatric obesity-associated asthma differed from atopic asthma and was characterized by Th1 polarization. The altered immune environment inversely correlated with PFTs in obese asthmatic children.