Cytofluorometric analysis of the neutrophil-specific BH2-Ag on cells from neonates to adults.

Monoclonal antibody (MAB) BH2C6 recognizes a plasma membrane antigen, the BH2-Ag, specifically expressed by human neutrophils. While studies with peripheral blood and bone marrow from healthy adults clearly demonstrate the absence of BH2-Ag from other cellular components except neutrophils, they also indicate that the BH2-Ag is expressed more strongly by mature than immature neutrophils. The purpose of this study was to determine the expression of the BH2-Ag by peripheral blood neutrophils from premature newborns to adults. Seventy-two donors were studied in six age groups: newborns <36 weeks of gestational age; newborns >36 weeks of gestational age; 0.5-2 years; 4-8 years; 12-17 years; >30 years. Expression of the BH2-Ag by peripheral blood neutrophils was examined by cytofluorography using MAB BH2-C6 directly labeled with fluorescein isothiocyanate (FITC). Neutrophils were reacted in parallel with FITC-MAB directed against CD11b, the alpha-chain of the CD11b/CD18 antigen (CR3). BH2-Ag is expressed by 98.3-99.6% of the neutrophils in all groups, and is absent on other blood cells, including those of very premature newborns. Statistical comparisons with respect to the mean fluorescence intensity of the FITC-MAB BH2C6 bound did not support a significant difference in the expression of BH2-Ag in any age group. CD11b expression was also detected in every individual studied and its mean fluorescence intensity correlated significantly with that of BH2Ag (p <0.001). The uniform presence of BH2Ag in every individual including a very premature infant suggests that BH2-Ag is likely to be an essential component of neutrophil development in humans. A highly significant correlation between the mean fluorescence intensity obtained with MAB BH2C6 and MAB CD11b suggests a possible interactive role of the two antigens in neutrophil development and/or function.

Tuberculosis in human immunodeficiency virus-infected and human immunodeficiency virus-exposed children in New York City. The New York City Pediatric Spectrum of HIV Disease Consortium.

BACKGROUND: Tuberculosis disease incidence increased sharply in New York City (NYC) in the late 1980s in children and adults. The relationship of tuberculosis disease in adults with the coincident epidemic of immunosuppression caused by HIV disease has been well-documented. This paper examines the relationship of tuberculosis and HIV in children in NYC. METHODS: Information on tuberculosis was collected by retrospective chart abstraction in a cohort of HIV-exposed and infected children enrolled in a longitudinal study of HIV. Tuberculosis cases were ascertained by chart review or by matching HIV-infected and -exposed children to NYC Tuberculosis Registry cases. NYC Tuberculosis Registry data on children reported from 1989 to 1995, and not reported as HIV-infected, were used for comparison. RESULTS: Tuberculosis disease was found in 45 (3%) of 1426 HIV-infected children (0.61 per 100 child years of observation) and in 5 (0.5%) of 1085 HIV-exposed uninfected children (0.2 per 100 child years). 30% of children were evaluated for HIV only after presenting with tuberculosis. Children with tuberculosis and HIV were more likely than other age-matched HIV-infected children to have decreased CD4+ T lymphocyte counts (66% vs. 37%, P = 0.02) and more likely than other NYC children with tuberculosis to have culture-confirmed and extrapulmonary tuberculosis. In this series 8 of 21 deaths in HIV-infected children with tuberculosis appeared to be related to tuberculosis. CONCLUSIONS: During a period of high tuberculosis incidence in NYC, 3% of HIV-infected children in our cohort had tuberculosis, higher than the rate in uninfected children born to HIV-positive mothers in the same cohort. Because of this association, HIV-infected children with pulmonary illness should be tested for tuberculosis; and all children with tuberculosis should be tested for HIV.

Expression of Fc(gamma)r1 (CD64) on polymorphonuclear leucocytes during progression to acquired immunodeficiency syndrome in perinatally human immunodeficiency virus-infected children.

CD64, the high-affinity receptor in the family of FCgamma receptors, is not expressed constitutively in polymorphonuclear leucocytes (PMN). CD64 is expressed by PMNs in the late stages of human immunodeficiency virus (HIV) infection in adults. We followed the expression of CD64 on PMNs in perinatally HIV-infected children during disease progression. Peripheral blood leucocytes (PBL) from 45 perinatally HIV-infected paediatric patients and 13 healthy age-matched controls were analysed using cytofluorimetry after reaction with a fluorophore-labelled monoclonal antibody (MoAb) to CD64. In parallel, we examined the expression of CD32, CD16, CD11b and the human neutrophil-specific BH2-Ag using fluorophore-labelled MoAbs. We found that up to 79.5% of the PMNs in children in class C3 express CD64. Most importantly, we observed a continuous and significant increase in the appearance of CD64+ PMNs as a function of CDC classification (P < 0.001) but no changes in the expression of CD32, CD16, CD11b and BH2-Ag. This suggests that following the expression of CD64 on PMNs can be useful in evaluating the progression of HIV infection in perinatally HIV-infected children.

Selective binding of a monoclonal antibody to Aspergillus niger glucose oxidase by formaldehyde fixed human polymorphonuclear leukocytes.

BACKGROUND: Many of the procedures used in handling neutrophils may affect the expression of surface antigens, and hence their quantitation by flow cytometry. METHODS: Because the enzyme glucose oxidase of Aspergillus niger is absent in human tissues, an IgM against it (mAb GO) was used as negative control in a study involving the normal expression of neutrophil specific BH2-Ag in different age groups. RESULTS: When peripheral blood leukocytes (PBL) were freshly prepared, processed and stained with FITC-mAb GO without fixation or when the cells were stained with FITC-mAb GO prior to fixation with 2% formaldehyde, both median fluorescent intensity (MFI) and per cent of positively stained polymorphonuclear leukocytes (PMN) were similar to that obtained with a background sample without any antibody. However, when PBL were fixed after isolation with different concentrations of formaldehyde and for varying durations, MFI and per cent of positively stained PMN but not of monocytes or lymphocytes with FITC-mAb GO increased in a time and concentration dependent manner. Saturation was achieved at a finite concentration of the antibody. In a competition assay unlabelled mAb GO reduced binding of FITC-mAb GO to PMN by 79% and 95% at concentrations 100 and 200 times that of FITC labelled antibody, respectively. CONCLUSIONS: These observations strongly suggest that formaldehyde fixation causes the expression or accessibility of an epitope on PMN that is specifically recognized by the mAb GO.

Impaired IgG antibody production to pneumococcal polysaccharides in patients with ataxia-telangiectasia.

Various factors seem to be etiologic in the susceptibility to sinopulmonary infections in ataxia-telangiectasia (A-T) patients, i.e., low serum and salivary IgA, low serum IgG2, and even aspiration of saliva. S. pneumoniae is a common pathogen responsible from pulmonary infections and impaired antibody response to polysaccharide antigens is seen in patients with IgG2 and IgA deficiency as well as patients with CVID and WAS. We studied IgG-type antibody production to six pneumococcal serotypes in 29 A-T patients by ELISA before and 3-4 weeks after pneumococcal vaccine. The response was considered positive when the antibody titer was >10 U/ml but weak when the titer was 10-20 U/ml. Twenty-two of 29 (76%) patients did not respond to any of the serotypes, 5 (17%) showed a positive response to one serotype, 1 (3.4%) to two serotypes, and 1 (3.4%) to four serotypes. With conversion to gravimetric units (ng IgG/ml) and >1800 ng/ml (300 ng Ab N/ml) considered a positive response, 5 of 29 (17.2%) patients showed a positive response (300 ng ab N/ml) to two or fewer serotypes. All patients tested produced IgG antibody to tetanus toxoid. Sixteen of 27 (59.3%) patients had low IgG2 and four (14.8%) had low IgG3 levels, while 18 (62.1%) of 29 patients had low serum IgA. No correlation was found either between serum Ig isotype levels and antipolysaccharide antibody response or between susceptibility to infection and antibody production. The mechanism responsible for disturbed antipolysaccharide (TI-2 antigen) antibody production in patients with A-T needs to be investigated. It may provide additional information on the function of the ATM gene product and be helpful in clarifying the role of B cells and contribution of T cells in TI-2 responses.

Ceftriaxone-related fatal hemolysis in an adolescent with perinatally acquired human immunodeficiency virus infection.

A 14-year-old girl with perinatally acquired human immunodeficiency virus infection had fatal intravascular hemolysis after intravenous administration of ceftriaxone. Laboratory studies confirmed the presence of an antibody against ceftriaxone in the serum and on the patient's red blood cells. No evidence of sepsis, glucose-6-phosphate dehydrogenase deficiency or anaphylaxis was found.

New onset diabetes mellitus in an HIV-positive adolescent.

The authors report an 18-year-old girl with HIV infection who developed new-onset insulin-dependent diabetes mellitus (IDDM) in association with anemia. IDDM among patients with HIV infection has been infrequently reported and suggested to be caused by different etiologies. Susceptibility to autoimmune diseases, such as IDDM, has been associated functionally with two members of a newly described multigene family called PERB11. In this patient, the progression of hyperglycemia associated with a rapid increase in insulin requirement is suggestive of insulin resistance.

Varicella-zoster virus infection in children with underlying human immunodeficiency virus infection.

This article describes a prospective longitudinal study of varicella-zoster virus (VZV) infections in human immunodeficiency virus (HIV)-infected children, designed to determine their natural history of VZV infection and possible effects of VZV on the progression of HIV infection. Varicella was usually not a serious acute problem, and it did not seem to precede clinical deterioration. The rate of zoster was high: 70% in children with low levels of CD4+ lymphocytes at the time of development of varicella. It is predicted that immunization with live attenuated varicella vaccine is unlikely to be deleterious to HIV-infected children. Moreover, if they are immunized when they still have relatively normal levels of CD4+ lymphocytes, they may have a lower rate of reactivation of VZV than if they were allowed to develop natural varicella when their CD4+ cell counts have fallen to low levels as a result of progressive HIV infection.

IgE against HIV proteins in clinically healthy children with HIV disease.

Elevated serum Ige was detected in 26% (7 of 30) of children with HIV infection. The majority of children with elevated IgE were of one ethnic group (Puerto Rican) (4 of 7), compared with only 9% (2 of 23) in the normal to low IgE group (p = 0.02). Most of the children with elevated IgE had decreased circulating CD4+ T cells (5 of 7 or 71%); but none had opportunistic infections, and none failed to thrive. Although similar numbers of children with normal to low IgE had decreased circulating CD4+ T cells (19 of 23 or 83%), this group had opportunistic infections (6 of 23 or 26%) and failure to thrive (7 of 30 or 30%). There was no difference in incidence of allergic symptoms between groups. IgE antibody against HIV protein was detected by Western blot technique in the sera of three children with elevated serum IgE. Thus we have identified a group of children with HIV infection and elevated serum IgE of predominantly one ethnic group, who are without opportunistic infections or failure to thrive, some of whom produce HIV-specific IgE. This suggests that IgE may play a protective (perhaps late compensatory) role in HIV disease in genetically predisposed individuals.

Childhood AIDS nephropathy: a 10-year experience.

The objective of this study was to define the demographic, immunologic, and clinical characteristics of children with acquired immunodeficiency syndrome (AIDS) and AIDS nephropathy, and contrast this with the existing adult data. Data from 62 pediatric patients with AIDS who were treated at SUNY Health Science Center, Brooklyn, New York, between 1983 and 1993 were analyzed. Human immunodeficiency virus (HIV) infection was acquired during the neonatal period by vertical transmission (n = 60) or blood transfusion (n = 2). All children with AIDS who exhibited clinical nephropathy died (n = 16), with mean survival of 55.3 months. In contrast, 32 of 56 AIDS patients (70%) who did not manifest nephropathy were alive at the end of the study period. Patients with nephropathy were noted to have significantly lower CD4+ lymphocyte counts than those without nephropathy. These observations suggest that the predominant renal lesion in pediatric patients who acquired HIV infection during the perinatal period is focal segmental glomerulosclerosis, although a variety of other histological lesions were present. As in adults, the survival in children is dismal following the onset of clinical renal disease. In contrast to the adult population in whom multiple risk factors can potentially contribute to AIDS-associated nephropathy, occurrence of nephropathy in children with vertical HIV transmission provides convincing evidence for the pathogenetic role of HIV infection.

Randomized study of the tolerance and efficacy of high- versus low-dose zidovudine in human immunodeficiency virus-infected children with mild to moderate symptoms (AIDS Clinical Trials Group 128). Pediatric AIDS Clinical Trials Group.

The current dosage of zidovudine for children is 180 mg/m2 every 6 h. To investigate whether a lower dosage was equally effective, human immunodeficiency virus (HIV)-infected children (3 months to 12 years) with mild to moderate symptoms were randomly assigned to receive either high-dose (180 mg/m2/dose) or low-dose (90 mg/m2/dose) zidovudine (double-blind). Treatments were compared with respect to neuropsychologic function, survival, clinical and laboratory evidence of disease progression, and safety and tolerance. Four hundred twenty-six HIV-infected children were enrolled; median time for receipt of study drug was 35 months. Zidovudine in either dose was well tolerated, with no difference in efficacy or tolerance by treatment group using any clinical or laboratory parameter. In children with mild to moderate disease, a reduction of zidovudine to 90 mg/m2/dose will result in substantial cost savings and should be the recommended dose.

Effect of naftifine on neutrophil adhesion.

Effective methods of fungal treatment involve reduction in fungal infections and host inflammatory responses. Naftifine (NF), a topical antifungal agent, is highly active in vitro and in vivo against a wide range of pathogenic fungi. Additionally NF has been shown to inhibit polymorphonuclear leukocyte (PMN) chemotaxis and respiratory burst activity in an irreversible dose-dependent and time-dependent manner. Since leukocyte adherence to endothelia is believed to be one of the initial crucial events in the recruitment of circulating leukocytes to the site of inflammation, we have investigated the in vitro effect of NF on PMN adherence to nylon fiber, BSA-coated glass chamber or polystyrene, and endothelial monolayers via three adherence assays. All three assays demonstrated a statistically significant reduction (p < 0.01-0.001) in PMN adherence to the respective media. In particular, NF (at 30-60 micrograms/ml) significantly inhibited PMN adherence to endothelial monolayers (p < 0.01) as measured spectrophotometrically by the uptake of rose bengal stain. Therefore, NF inhibits PMN adherence to endothelia in our in vitro model system. This inhibition may constitute part of the anti-inflammatory effect of NF.

Cerebral infarction in pediatric acquired immunodeficiency syndrome.

Cerebral infarction is an uncommon complication of AIDS in pediatric patients. We have seen three HIV-infected children who developed acute neurological deficits due to stroke. Cerebral infarction must be considered in the work-up of a child with AIDS who presents with focal neurological deficit, seizure or mental status change. Stroke is a complication of HIV infection that occurs in approximately 1% of affected children [1]. At autopsy, evidence of cerebral infarction was documented in 10-30% of children with HIV infection [2]. We have seen three children with focal infarction who are HIV positive.

Modification of neutrophil functions by naftifine.

Naftifine (NF), a topical antimycotic agent, is highly active in vitro and in vivo against a wide range of pathogenic fungi. NF inhibits human polymorphonuclear leucocyte (PMN) chemotaxis. Following stimulation with zymosan-activated serum, 85-97% of the PMNs exhibited detectable membrane ruffling and polarity. In contrast, NF-treated PMNs did not exhibit such chemotactic factor-induced shape changes. We also analysed the effect of NF on PMN superoxide anion (O2-) and chemiluminescence (CL) production, as a measure of respiratory burst activity. Stimulation of PMNs pre-incubated with NF (37 degrees C for 30 min at 1-150 micrograms/ml) by FMLP, PMA and zymosan resulted in a dose-dependent inhibition in PMN CL. Doses of NF which depressed chemotaxis, inhibited CL and diminished O2- production in a statistically significant manner (P < 0.05-0.001). In conclusion, NF alters membrane-related responses in PMNs, and this alteration may be associated with a change in PMN morphology. Binding of NF to PMN membrane sterol, with a subsequent alteration in membrane configuration, is the most likely cause of the inhibition of PMN function. The data collectively document biochemical and morphological differences between control and NF-treated PMNs as determined by stimulus-specific CL and O2- generation and membrane shape change. Such differences may account, in part, for its efficacy in inflammatory fungal skin diseases.

Aspergillosis in children with acquired immune deficiency.

Two children are presented with AIDS and aspergillosis. One child had pulmonary involvement while the other had invasion of the skull and brain. The rarity of aspergillosis in AIDS patients is discussed as well.