Prognostic value of a CCR5 defective allele in pediatric HIV-1 infection

BACKGROUND

A deletion of 32 base pairs in the CCR5 gene (delta32 CCR5) has been linked to resistance to HIV-1 infection in exposed adults and to the delay of disease progression in infected adults.

MATERIALS AND METHODS

To determine the role of delta32 CCR5 in disease progression of HIV-1 infected children born to seropositive mothers, we studied a polymerase chain reaction in 301 HIV-1 infected, 262 HIV-1 exposed-uninfected and 47 HIV-1 unexposed-uninfected children of Spanish and Italian origin. Infected children were further divided into two groups according to their rate of HIV-1 disease progression: rapid progressors who developed severe clinical and/or immunological conditions within the second year of life, and delayed progressors with any other evolution of disease. Among the latter were the long-term, non-progressors (LTNP) who presented with mild or no symptoms of HIV-1 infection above 8 years of age. Viral phenotype was studied for 45 delayed progressors.

RESULTS

No correlation was found between delta32 CCR5 and mother-to-child transmission of HIV-1. However, the frequency of the deletion was substantially higher in LTNP, compared with delayed (p = 0.019) and rapid progressors (p = 0.0003). In children carrying the delta32 CCRS mutation, the presence of MT-2 tropic virus isolate was associated with a severe immune suppression (p = 0.028); whereas, the presence of MT-2 negative viruses correlated with LTNP (p = 0.010).

CONCLUSIONS

Given the rapidity and simplicity of the assay, the delta32 CCR5 mutation may be a useful predictive marker to identify children with delayed disease progression who, consequently, may not require immediate antiretroviral treatment.

High rate of maternal-infant transmission of hepatitis G virus in HIV-1 and hepatitis C virus-infected women

The prevalence of hepatitis G virus (HGV) infection was investigated in 56 mothers with both human immunodeficiency virus type 1 (HIV-1) and hepatitis C virus (HCV) infection. Thirty-three (58.8%) women had markers of HGV infection, including 7/15 (46.6%) with no history of parenteral exposure to blood. Sixteen (48%) had HGV RNA in serum by a polymerase chain reaction assay, and 17 (52%) had antibody to E2 viral protein. No woman was positive for both markers. Of 20 infants born to the 16 mothers with HGV viremia, 9 (45%, 95% CI 34-56%) acquired the infection. No infected child seroconverted to HGV during the first year of life. At the latest visit (mean: 37.1 mo, range: 9-89 mo) 7 children were still seronegative HGV RNA carriers, 1 was both RNA- and antibody-negative, while 1 RNA-negative child had developed the E2 antibody. Of the 20 HGV-exposed infants, 2 contracted HCV and 1 HIV-1 (all 3 with HGV coinfection). No abnormalities in clinical findings and ALT levels were observed throughout the follow-up period in the six children with HGV infection alone. Our findings show that HGV infection is widespread among HIV-1- and HCV-infected women. Maternal-infant transmission of HGV is common and occurs independently from that of HIV-1 and HCV in women with triple infection. Most perinatally HGV-infected children develop persistent infection with no clinical or biological signs of liver damage, at least in the first years of life.

Carbonaceous grain processing in space and in the laboratory

Laboratory simulations of carbonaceous grain processing which occurs in space are fundamental to outline an evolutionary pathway for these particles. We consider the UV spectral changes induced in hydrogenated carbon grains by thermal annealing, UV irradiation and ion bombardment. The results give the opportunity to interpret observations in different space environments. In particular, modelling of the optical properties, based on a description of the electronic structure of carbons, indicates small hydrogenated amorphous carbon grains, with different degrees of UV irradiation, as the carrier of the ubiquitous UV interstellar extinction bump.

Effects of the major Pasteurella multocida porin on bovine neutrophils

OBJECTIVE

To evaluate in vitro effect of the major fraction of outer membrane proteins of Pasteurella multocida with porin-like activities on some biological functions of bovine neutrophils.

ANIMALS

Neutrophils from 5 adult cattle.

PROCEDURE

Variations in such biological processes as actin polymerization and chemotaxis and evaluation of hydrogen peroxide attributable to variable concentrations of P multocida were recorded and compared. Data were obtained, using the porin and lipopolysaccharide (LPS) isolated from a strain of P multocida cultivated in brain-heart infusion (BHI) broth. Various concentrations of porin and LPS were analyzed to evaluate changes in functional activation and microbicidal activity of bovine neutrophils.

RESULTS

The 37.5-kd major polypeptide of the outer membrane of P multocida was isolated. Presence of this porin was significantly correlated with variations of some biological functions of bovine neutrophils. These immunocompetent cells had a concentration-dependent increase in actin polymerization and chemotactic activity. A concentration-dependent variation in the oxidative burst also was observed.

CONCLUSIONS

The porins of gram-negative bacteria affect several biological functions of cells involved in the immune response as well as in inflammation. Significant correlation of results of in vitro experiments also was identified between porin and LPS effect. Pretreatment of bovine neutrophils with various concentrations of porin always caused a concentration-dependent increase in examined biological activities.

Long-term resistance to HIV infection in vertical HIV infection: cytokine production, HIV isolation, and HIV phenotype define long-term resistant hosts

We analyzed immunologic (CD4 and CD8 slopes; interferon-gamma, interleukin-2, interleukin-10, and chemokines production; concentration of IgE; beta 2-microglobulin) and virologic (p24; HIV isolability and phenotype; plasma viremia) parameters in HIV vertically infected children > or = 8 years of age without disease progression or mild symptoms and an absolute CD4+ count > or = 500/microliter with CD4+ percentage > or = 25%. The results were compared to those of two control groups: (1) slow progressors, children > or = 8 years of age with moderate symptomatology and/or moderate CD4 depletion, and (2) progressors, children > or = 8 years of age with severe clinical disease and/or severe CD4 depletion. Pediatric long-term resistant hosts were characterized by higher production of interleukin-2 and interferon-gamma and lower production of interleukin-10, normal concentration of IgE, HIV isolates with a non-syncytium-inducing phenotype, and lower plasma viremia. This condition was not associated with the concentration of beta 2-microglobulin, p24, and chemokines, or with HIV isolability. The IL-10/IL-2 ratio best correlated with both CD4 counts and disease progression. Thus, vertically infected children showing resistance to disease progression are immunologically and virologically distinct from those in whom progressive HIV infection is observed.

Increased risk of maternal-infant hepatitis C virus transmission for women coinfected with human immunodeficiency virus type 1. Italian Study Group for HCV Infection in Children

To estimate the risk of mother-to-child transmission of hepatitis C virus (HCV) and identify correlates of transmission, 245 perinatally exposed singleton children followed prospectively beyond 18 months of age were studied. Overall, 28 (11.4%) of the 245 children acquired HCV infection. Transmission occurred in 3 of 80 children (3.7%) whose mothers had HCV infection alone and in 25 of 165 (15.1%; P < .01) whose mothers had concurrent infection with human immunodeficiency virus type 1 (HIV-1). The percentage of HIV-1-infected children was similar (22 of 165, 13.3%), but each virus was transmitted independently; only six infants (3.6%) were coinfected with HCV and HIV-1. The risk of HCV transmission was not associated with maternal HIV-1-related symptoms, intravenous drug use, prematurity, low birth weight, or breast-feeding, whereas it was lower with cesarean section than with vaginal delivery (5.6% vs. 13.9%, P = .06). This suggests that transmission occurs mainly around the time of delivery.

ACTH and cortisol secretions in children with perinatal HIV-1 infection

Serum cortisol and adrenocorticotropic hormone (ACTH) values and CD4 cell count were evaluated in 25 perinatally HIV-1-infected children. The children were divided into three groups: group 1 included eight asymptomatic or paucisymptomatic children, group 2 nine moderately symptomatic children, and group 3 eight children with severe clinical manifestations. Group 1 children were without antiretroviral therapy; the remaining children received zidovudine (AZT) treatment. Only one group 3 patient had primary adrenal insufficiency. No significant differences in cortisol and ACTH secretion were found either between all HIV-1-infected and 126 age- and sex-matched normal children or among the three groups of patients. Mean CD4 cell count of each group declined in parallel to disease progression. No correlations were found between cortisol or ACTH values and CD4 cell count. Adrenal failure may be a late complication of HIV-1 infection and should be searched for in severely ill patients. Our data argue against the hypothesis of a cortisol-induced shift from T-helper-1 (Th1) to Th2 cytokine production profile as the pathogenetic mechanism of progression to AIDS.

Natural history of perinatal hepatitis C virus infection

In order to outline the natural course of perinatal hepatitis C virus (HCV) infection, we prospectively followed seven HCV-positive children for a mean period of 65.1 months (range, 26-90 months). Physical examination findings, growth, and bilirubin and immunoglobulin levels were constantly normal. All children were still viremic at last analysis. HCV-RNA was almost constantly detected throughout follow-up, with the exception of the first days of life. All children had initial increases (of variable duration) in alanine aminotransferase values: four children subsequently had normal or borderline values for years, with exacerbation of inflammatory activity in two cases. IgM antibodies to HCV were found in three of the seven patients. Autoantibodies developed in two children. Liver biopsy, performed on five patients, documented different degrees of chronic persistent hepatitis. Thus, recovery from perinatal HCV infection seems unlikely, and chronic hepatitis develops in most infected children, including those with prolonged intervals of remission of inflammatory activity.

Iron deficiency and intestinal malabsorption in HIV disease

Children with human immunodeficiency virus (HIV) infection have a higher prevalence of intestinal malabsorption. Anemia is also a common feature in these children. The aims of this work were (a) to establish the prevalence of iron deficiency in HIV-infected children, (b) to test the hypothesis that iron deficiency is related to intestinal malabsorption, (c) to see whether it may contribute to anemia, and (d) to evaluate the sensitivity of oral iron load in the investigation of intestinal function. To accomplish these goals, 71 HIV-infected symptomatic children were enrolled. Iron serum values were determined before and after oral load with ferrous sulfate. The correlation between basal and post-load iron levels was evaluated by linear regression. Xylose level after oral load, fecal fat, and fecal alpha 1-antitrypsin concentration were also determined. Iron deficiency was detected in 48% of patients, and it was significantly associated with intestinal iron malabsorption. Sugar malabsorption, steatorrhea, and fecal protein loss were detected in 26, 36, and 17% of patients, respectively. Low hemoglobin levels were detected in 66% of patients. The majority of children with iron deficiency also had anemia. Preliminary data showed that oral iron administration was sufficient for raising hemoglobin in children with normal iron absorption, whereas parenteral administration was required in those with iron malabsorption. We conclude that (a) iron deficiency is a major feature of pediatric HIV infection, (b) it is related to intestinal malabsorption, and (c) it contributes to anemia. Finally, oral iron load is a sensitive test for investigating intestinal function.

Anti-HIV-1 antibody avidity is correlated with clinical status in infected children

Avidity of antibodies to gp41 and p24, CD4 cell count, and free and dissociated p24 antigen were assessed in 37 HIV-1-infected children, in order to evaluate whether the avidity of anti-HIV-1 antibodies is related to the disease status in perinatally infected children. The HIV-infected children were divided into two groups. Group 1 included 25 children: 2 not symptomatic (CDC category N), 12 mildly (A) and 11 moderately (B) symptomatic; group 2 included 12 children with severe clinical manifestations (C). The same parameters were assayed longitudinally in four children: two with long-term nonprogressive disease and two with fatal outcome. Antibody avidity was significantly higher in group 1 than in group 2 children (7272 +/- 4788 vs. 2624 +/- 1344 D50, p < 0.01), as was the CD4 cell count (1295 +/- 1122 vs. 348 +/- 488 cells/mm3, p < 0.01). No differences between the two groups were observed in either free or dissociated p24 antigen. Combined measures of antibody avidity and CD4 cell count showed the best correlation with the clinical status (r = 0.57, p = 0.001). In the two children with nonprogressive disease the antibody avidity remained high throughout the follow-up, whereas in those with clinical deterioration its decline preceded, by at least 8 months, the drop in CD4 cells and, by at least 23 months, the appearance of AIDS. In conclusion the avidity of anti-HIV-1 antibodies is reduced in HIV-infected children with advanced disease state and seems an earlier predictor of disease progression than CD4 cell count.

Human immunodeficiency virus infection as risk factor for mother-to-child hepatitis C virus transmission; persistence of anti-hepatitis C virus in children is associated with the mother's anti-hepatitis C virus immunoblotting pattern

To determine the rate of vertical transmission of hepatitis C virus (HCV), we prospectively studied 45 babies born to anti-HCV-positive women with or without concomitant infection with the human immunodeficiency virus (HIV). We performed a second-generation recombinant immunoblotting assay, alanine transaminase (ALT) evaluation, and HCV-RNA testing on sera from 27 infants of HCV+, HIV- mothers and 18 babies of HCV+, HIV+ women, at birth and thereafter. After birth, HCV antibodies progressively disappeared within 12 months in all children but one, whose mother was HCV+, HIV+; this child was the only one who showed detectable levels of HCV-RNA and abnormal ALT values throughout the follow-up (range, 12 to 27 months). Viremia was persistently negative, and ALT levels were continuously normal in the remaining infants, showing that "seronegative" infection with HCV was absent in both groups. Clearance of passively acquired anti-HCV antibodies was found to be slower among babies born to HIV+ mothers (22.3% vs. 3.8% at 12 months, P = .03) and children whose mothers showed three or four anti-HCV reactivities by immunoblotting maintained anti-HCV for longer periods compared with babies born to mothers with one or two anti-HCV reactivities (P = .0001). Seventeen of 27 babies born to HCV+, HIV- mothers were breast-fed, and none of them was infected, confirming the apparent safety for HCV of breast milk. In summary, according to our study, vertical transmission of HCV is an infrequent event, and the presence of HIV in the mother is not an important co-factor for transmission of HCV infection.

Reduced immunoglobulin kappa/lambda light chain ratio in perinatally HIV-1-infected children

In 27 perinatally human immunodeficiency virus type 1 (HIV-1)-infected children, we measured, by immunonephelometry, the kappa/lambda light chain ratio (KLR) of serum immunoglobulins. The latter is a recently available laboratory index reflecting the balance between the synthesis of K isotypes and L isotypes. KLR was consistent over time in each subject, and was significantly lower than that of an age-matched normal population, independently of disease status and therapy. These data indicate a bias, in these subjects, to produce preferentially lambda rather than kappa light chains, contributing to the multiple B-cell abnormalities in HIV-1-infected children.

Growth impairment, IGF I hyposecretion and thyroid dysfunction in children with perinatal HIV-1 infection

We evaluated the growth pattern, bone age, insulin-like growth factor I (IGF I) secretion and thyroid function in 24 perinatally infected children: 9 asymptomatic or paucisymptomatic (group 1) and 15 with a more advanced disease state and treated with zidovudine (group 2). Statural and ponderal growth were compared with those of 37 at-risk children who seroreverted. During the two-year follow-up, 22% of children in group 1 had impaired growth, 33% bone age delay, 45% reduced IGF I levels but none had thyroid dysfunction. In group 2, 53% had growth failure, 53% bone age delay, 86% reduced IGF I levels and 40% thyroid dysfunction. Among seroreverters, none showed growth impairment; statistically significant differences were found for height, weight and height velocity between perinatally infected children and seroreverters. Since auxological and hormonal evaluations run parallel to the clinical course of infection, these indices may be useful in monitoring disease progression.

Asymptomatic women at high risk of vertical HIV-1 transmission to their fetuses

OBJECTIVE

To identify how reliably CD4+ (helper) lymphocyte count and p24 antigenaemia can predict mother-to-infant transmission of human immunodeficiency virus type 1 (HIV-1).

DESIGN

Prospective study.

SETTING

University of Turin Center for Intravenous Drug Users (IVDU) and/or HIV-1 seropositive pregnant women.

SUBJECTS

Twenty-nine infants born to asymptomatic seropositive women from November 1985 to June 1991.

RESULTS

Seven children (24%) developed symptomatic infection, while 22 healthy seronegative children at the age of 18 months were considered uninfected. A CD4+ lymphocyte count persistently < 500/mm3 during pregnancy was associated significantly with the child's infection status with a relative risk (RR) of 11.4. (CI 1.58-82.05). A marked association (RR 13.6) (CI 1.93-95.72) was similarly detected between maternal antigenaemia and the risk of the child being infected. In a multivariate logistic analysis, crude and adjusted odds ratios (OR) of transmission were 27.0 (95% CI 2.5-291.2) and 35.6 (1.1-1159) for low CD4+ counts; 64 (3.2-1261) and 51.6 (2.5-1058) for p24 antigenaemia.

CONCLUSIONS

Asymptomatic HIV positive women with a CD4+ count below 500/mm3 or p24 antigenaemia are about ten times as likely to transmit the virus to their children. CD4+ lymphocytes decrease during pregnancy and a low CD4+ cell count early in pregnancy remains low up to delivery. Therefore knowledge that they have a low CD4+ lymphocyte count early in pregnancy may help women to decide whether or not to continue their pregnancy.

Oral lesions in children born to HIV-1 positive women

A cohort of 69 children born to HIV-1 positive women was studied to evaluate types, prevalences and relationships to clinical stages of HIV-1-related oral lesions. In addition, relationships among C. albicans biotypes, clinical features of oral candidiasis and HIV-1 disease were investigated. C. albicans biotypes did not correlate with clinical features of oral lesions, disease stages and CD4+ lymphocyte count. Of 8 patients with recurrent oral candidiasis, 4 changed clinical features and 5 changed biotype. Our study pointed out the high frequency (28.9%) of oral lesions, especially caused by fungi and the importance of the examination of the oral cavity in children born to HIV-1 positive women.