Immune response in HIV-1-infected children with thalassaemia given a primary course of DPT vaccine before acquiring HIV-1 infection

The effect of HIV infection on immune response to diphtheria and tetanus primary immunisation was investigated in 24 HIV-1-positive multi-transfused (MT) children with thalassaemia and compared with 48 HIV-1-negative MT thalassaemic children and 36 HIV-1-negative non-transfused (NT) children in the community. Diphtheria and tetanus antibody levels in the HIV-1-positive MT group were comparable with the two HIV-negative groups. The proportions of children with antibody titres below the protective level (i.e. <0.01 IU/ml) for antidiphtheria antibodies were 20.8, 16.6 and 16.6%, and 12.5, 12.5 and 13.9% for anti-tetanus antibodies in the three groups, respectively. On the other hand, delayed-type hypersensitivity (DTH) response to diphtheria and tetanus antigens was significantly depressed in the HIV-1-positive group compared with the HIV-negative controls. The mean percentages of both mature (CD20+) and immature (CD10+) B-cell counts were significantly higher in the HIV-1-positive group than in the HIV-negative MT and NT groups (p<0.05). Levels of serum immunoglobulins and spontaneously secreted immunoglobulins were significantly higher in the HIV-1-positive group compared with both HIV-negative groups. The HIV-1-positive group showed a mean (SD) IL-6 of 52.9 (28.8) pg/ml compared with 23.7 (12.1) pg/ml and a detection rate of 54.2% in the HIV-negative MT group, and 23.6 (8.2) pg/ml and a 50% detection rate in the HIV-negative NT group. The IL-2 level was significantly lower (p<0.05) in the HIV-1-positive group [41.7% detection rate and mean (SD) 28.8 (17.1) pg/ml] than in the HIV-negative MT and NT groups [75% and 83.3% detection rates and mean (SD) 57.2 (42.3) pg/ml and 99.3 (51.1) pg/ml, respectively]. During follow-up for 3 years, the frequency of major infections was significantly higher in the HIV-1-positive group than in the other two groups. Acute pneumonia and acute sinusitis were the predominant infections regardless of HIV status while primary bacteraemia, osteomyelitis, pyogenic meningitis and septic arthritis were common in the HIV-1-positive group. We conclude that, in HIV-1-infected children pre-immunised with DPT, DTH response to diphtheria and tetanus antigens might be more reliable than anti-diphtheria and anti-tetanus antibody levels in predicting susceptibility to major bacterial infections.     

Antibodies to human immunodeficiency virus in the breast milk of healthy, seropositive women

Reports of rare cases of suspected transmission of the human immunodeficiency virus (HIV) from mother to children by breast milk have been recently published. To study the factors that possibly limit HIV transmission through breast-feeding, milk samples obtained from 15 healthy, seropositive mothers and 4 seronegative control subjects were studied for the presence of anti-HIV antibodies. All samples from seropositive women contained IgG antibody against envelope glycoproteins gp160 and/or gp120, and 11 of 15 samples contained IgA antibodies against gp160. IgA antibodies against other viral antigens were more rarely recovered, except against the internal proteins of the virus, p18 and p25. The finding of IgA antibodies to HIV-1 in breast milk establishes that the virus elicits a local immune response in heterosexual, seropositive women. The role of local antibodies in the postnatal transmission of HIV remains to be determined.     

Immunologic and immunogenetic studies in rheumatic fever and rheumatic heart disease

In order to evaluate all the important limbs of the immune system in the same patient population with rheumatic fever (RF) and rheumatic heart disease (RHD) cellular and humoral immune parameters as well as the immunogenetic profile in 265 North Indian patients with RHD were evaluated. They were studied for class in HLA antigens and 165 of them were also evaluated for the class II (DR locus) antigen profile. Data obtained was compared with 400 and 134 healthy controls respectively of the same ethnicity. Humoral immune parameters (Serum immunoglobulins IgG, IgA; Serum complement fractions C3, C4, C3d; circulating immune complexes and B lymphocyte numbers) and cellular immune parameters (total leucocyte and lymphocyte counts; T lymphocyte sub-populations-CD4, CD8 counts; lymphocyte migration inhibition to an extracellular streptococcal antigen, streptolysin ’O’) were studied in 23 patients with RF, 21 patients with “inactive” RHD and 20 normal controls. Patients of RHD were noted to have an increased frequency of DR3 (P < 0.001; Relative risk = 2.3) and a decreased frequency of DR2 (P < 0.001; Relative risk = 0.3) as compared to the controls. Patients of RF had evidence of an altered regulatory T cell function (Increased CD4/CD8 ratio) and decreased cell mediated immunity to streptolysin ‘0’. An increased humoral immune response (increased B cell counts, elevated serum IgG, circulating immune complexes and C3d) was noted in patients of RF as well as “inactive” RHD. An integrated pathogenetic model with immune response associated antigens of the DR locus influencing selection of cardiac cross-reactive antigens by the antigen processing macrophages, an altered regulatory T cell function with decreased suppressor T cell activity leading to an abnormal immune response is proposed to explain the pathogenesis of RF.     

Quantification of human immunodeficiency virus type 1 p24 antigen and antibody rivals human immunodeficiency virus type 1 RNA and CD4+ enumeration for prognosis. National Institute of Child Health and Human Development Intravenous Immunoglobulin Clinical Trial Study Group

BACKGROUND: The sensitivity, specificity and positive predictive value of baseline serum concentrations of HIV-1 immune complex-dissociated (ICD) p24 antigen for predicting disease progression and mortality were assessed and compared with results obtained for HIV-1 ICD p24 antigen with HIV-1 p24 antibody and for HIV-1 RNA with CD4+ lymphocyte percent. METHODS: Data from HIV-infected children enrolled in a North American clinical trial (National Institute of Child Health and Human Development Intravenous Immunoglobulin Clinical Trial) were analyzed. Disease progression was defined as growth failure, CD4+ lymphocyte percent decline to <15% after study entry or development of an AIDS-defining opportunistic infection. RESULTS: Baseline samples were available for ICD p24 antigen testing (median concentration, 319 pg/ml; range, <50 to 15,640) in 240 children. The combination of detectable ICD p24 antigen and low p24 antibody was more sensitive but less specific than the combination of high HIV-1 RNA and low CD4+ lymphocyte percent in predicting disease progression and mortality. Using receiver operating characteristic curves, the specificity of ICD p24 antigen with p24 antibody for classifying children's disease progression or mortality was as great as, or greater than, HIV-1 RNA with CD4+ lymphocyte percent at points on the curve corresponding to higher sensitivity. CONCLUSIONS: The use of ICD p24 antigen with p24 antibody to identify children at high risk of disease progression or mortality could be a viable alternative to the more expensive and technically difficult HIV-1 RNA and CD4+ lymphocyte assays in resource-poor settings, including developing countries where the majority of children with HIV-1 infection reside.     

Human immunodeficiency virus type 1 antigenemia in children

Human immunodeficiency virus type 1 (HIV-1) core antigen was assayed in the plasma of children at risk for infection with HIV to determine its usefulness in the diagnosis of infection and to correlate it with the clinical stage of disease. Antigen was detected in the plasma of all children less than 15 months of age with acquired immunodeficiency syndrome (AIDS). Two thirds of children with AIDS-related illnesses and half of children with asymptomatic infection had antigen. Although 53% of plasma specimens originating from HIV-infected children younger than 6 months of age contained antigen, only 25% of plasma specimens from children younger than 6 months who had no symptoms and none of the 10 specimens from HIV-infected newborn infants contained antigen. Half of the specimens containing core antigen also contained anticore antibody. Quantitative mean antigen levels were more likely to be elevated in children with AIDS (516 pg/ml) than in children with AIDS-related illnesses (295 pg/ml) or in those who had no symptoms (70 pg/ml). Antigen levels tended to increase over time in children with advancing clinical illness, but they tended to decrease over time after a diagnosis of AIDS was made. Antigen was detected in the plasma of 4 of 14 children without symptoms who subsequently reverted to an HIV seronegative state. We conclude that the detection of core antigen occurs with high frequency in children, even young infants, with symptomatic HIV infection. Plasma core antigen was less frequent in children without symptoms and was not detected in 10 infected children when they were tested at birth.     

Response to influenza virus vaccination in vertical HIV infection

OBJECTIVE: To assess the antibody response to influenza vaccine of children vertically infected with HIV. DESIGN: Prospective study in HIV infected children vaccinated during the winter of 1994-5. SETTING: Family HIV clinic at St Mary's Hospital, Paddington. SUBJECTS: 25 children, aged 1-11 years, vertically infected with HIV. MAIN OUTCOME MEASURES: Responses to influenza antigens (H1N1-A/Taiwan/1/86, H3N2-A/Shandong/9/93, B/Panama/45/ 90) were tested by haemagglutination inhibition. Antibody responses were assessed according to clinical symptoms and immune function, stratified according to the 1994 revised classification for HIV infection in children. RESULTS: 23 children (92%) had either very low or no detectable antibody before vaccination. New protective antibody responses were made by 10 children (40%): in seven to a single antigen, in two to two antigens, and in one to all three antigens. For each antigen there was an overall small increase in the mean geometric titre of antibody produced, but this only reached a protective level for antigen H1N1 and for children with minimal symptoms. Less symptomatic children were significantly more likely to produce a protective antibody response to influenza vaccination. No association was found between immune function, as measured by CD4 count, and vaccine response. CONCLUSIONS: Only vaccination of the least symptomatic HIV infected children against influenza is likely to be effective. This will not only protect them against influenza, but will also protect other more immunosuppressed and vulnerable members of their families.     

Glomerular alterations in children with biliary atresia.

To investigate the association of glomerular involvement with biliary atresia, we carried out the following studies: (1) review of the clinical records of 120 patients, (2) histologic study of the kidneys obtained at autopsy from 28 patients, and (3) measurements of circulating immune complexes. Of 90 patients with adequate follow-up information, 40 (44.4%) had hematuria, proteinuria, or both. All the kidney specimens showed a wide variety of mesangial proliferation, and immunoglobulins were present in 23 of 26 cases. There was a good correlation between the glomerular alterations and the period of reduced hepatic function. When IgA was present in the mesangium, IgA2 and secretory components were detected. Elevated serum IgA and circulating IgA-containing immune complex levels were found in patients with prolonged obstructive jaundice. These findings indicate that glomerular alterations may occur subsequently in patients with biliary atresia, and that IgA of intestinal mucosal origin plays some role in the development of these lesions.     

Immunoglobulin G subclasses in serum and circulating immune complexes in patients with Kawasaki syndrome

IgG subclass concentrations in sera of 17 patients with Kawasaki syndrome were determined. Significantly increased IgG1 (P less than 0.001) and IgG3 (P less than 0.001) were found in the patients compared with 22 age-matched healthy children, whereas IgG2 and IgG4 were normal or slightly decreased. IgG immune complexes were measured by protein A-enzyme-linked immunosorbent assay (ELISA) combined polyethylene glycol precipitations. Eight of 17 patients (47.1%) were found to have circulating immune complexes (CIC) values above the normal control range (geometric mean +2 SD). IgG subclass composition in CIC was analyzed. The subclasses in CIC were predominantly IgG1 and IgG3. Because the antibody responses to different antigens exhibit IgG subclass restriction, it would suggest that the change of serum and CIC IgG subclasses in Kawasaki syndrome may have relevance to the pathogenesis of the disease.     

Immune-complex-mediated glomerulonephritis and pulmonary hemorrhage simulating Goodpasture syndrome.

Two female children whose clinical presentations and renal light-microscopic findings were consistent with Goodpasture syndrome are described. Immunopathologic studies demonstrated granular deposition of immunoglobulins and complement, suggesting that the renal disease was mediated by circulating immune complexes and not by anti-glomerular basement membrane antibody. Anti-GBM antibody was absent in both patients. These patients represent the first report in children of idiopathic nephritis due to immune complexes with associated pulmonary hemorrhage. The findings raise some doubt as to the accuracy of previous reports of Goodpasture syndrome in children, and also demonstrate the diagnostic and therapeutic importance of evaluation the renal immunopathology in the child with nephritis and pulmonary hemorrhage.     

Immunogenicity of Haemophilus influenzae type b polysaccharide-outer membrane protein conjugate vaccine in patients who acquired Haemophilus disease despite previous vaccination with type b polysaccharide vaccine

To investigate the basis of the immune defect in children who acquire invasive Haemophilus disease despite previous vaccination with Haemophilus influenzae type b (Hib) polysaccharide vaccine, we determined the ability of vaccine failure patients with low levels of serum anticapsular antibody (less than 1 microgram/ml) to respond to reimmunization. Thirty-four patients, ranging in age from 27 to 61 months, were vaccinated with either Hib polysaccharide (n = 20) or Hib polysaccharide-outer membrane protein conjugate vaccine (n = 14). All but three of the children had normal serum concentrations of immunoglobulins, including IgG2. The geometric mean serum anticapsular antibody concentration of the group given polysaccharide vaccine increased from 0.27 microgram/ml before vaccination to 0.65 microgram/ml 1 month later (p less than 0.05), but the magnitude of the response was nearly 10-fold less than that of 31 age-matched control children given polysaccharide vaccine (6.3 micrograms/ml, p less than 0.001). In contrast, all 14 patients with vaccine failure who were given conjugate vaccine showed increases of fivefold or more in serum anticapsular antibody (geometric means 0.35 and 12.8 micrograms/ml, respectively; p less than 0.001). All patients with vaccine failure who did not respond to polysaccharide vaccine were subsequently given conjugate vaccine, and all had high antibody responses. Most patients tested showed increases in complement-mediated serum bactericidal activity. These data suggest that immunization with conjugate vaccine confers protection against Hib disease to children who, because of genetic or other reasons, cannot respond to the unconjugated form of the polysaccharide vaccine.     

Serum tumor necrosis factor alpha, interleukin 1-beta, p24 antigen concentrations and CD4+ cells at various stages of human immunodeficiency virus 1 infection in children.

We measured the serum concentrations of tumor necrosis factor (TNF-alpha), interleukin 1-beta (IL-1-beta), p24 antigen, CD4+/CD8+ cells and immunoglobulins in 35 children at various stages of human immunodeficiency virus infection. Serum TNF-alpha concentrations were significantly higher in children with lymphocytic interstitial pneumonitis and in children with mildly symptomatic illness than in asymptomatic children or children with acquired immunodeficiency syndrome. In addition serum IL-1 concentrations were significantly higher in patients with lymphocytic interstitial pneumonitis than in asymptomatic, mildly symptomatic, or acquired immunodeficiency syndrome patients. Children with lymphocytic interstitial pneumonitis had the highest serum TNF-alpha and IL-1 concentrations. Among symptomatic children serum TNF-alpha concentrations correlated positively with those of IL-1, and both were inversely related to the amount of p24 antigen. TNF-alpha values in excess of 50 pg/ml were observed more frequently among patients with CD4+ cell count greater than 400/mm3 than in those with CD4+ cell count less than 400/mm3. We did not find any association between elevated TNF-alpha concentrations and cachexia, opportunistic infections or progressive encephalopathy.     

Participation of immune complexes in adenovirus infection

To determine the participation of immune complexes during adenovirus infection, we evaluated serum and necropsy specimens of patients with confirmed adenovirus infection of the lower respiratory tract. In lung and kidney from seven dead patients, immunofluorescence revealed the presence of hexon, immunoglobulins and complement. These patients had clinical manifestations of kidney dysfunction. In dead patients (3/3 in whom serum was available) neither anti-adenovirus antibodies nor adenovirus-specific immune complexes could be found in the final stage of the infection. However, two of these patients had anti-adenovirus antibodies and immune complexes in samples obtained early in the infection. Most patients (16/19) who survived the infection had circulating anti-adenovirus antibodies. Half also had immune complexes specific for adenovirus in some moment of the illness. This suggests that immune complexes arise during respiratory infection by adenovirus, probably contributing to its clinical picture.     

Autoantibodies in minimal change nephrotic syndrome

The presence of low level antibody (AAb) activity and circulating immune complexes (CIC) were studied in 17 patients with minimal change nephrotic syndrome (MCNS). Study groups include 12 MCNS without mesangial deposits (Group I) and 5 MCNS with mesangial deposits (Group II). In Group I reactivity against normal tissue antigens was demonstrated (kidney tubular microsomal antigen - 8, smooth muscle - 5, gastric cell - 5). In Group II reactivity against kidney basement membrane was demonstrated in all five patients. CIC were detected in eight (Group I - 6, Group II - 2). Dissociation of the CIC showed that they all contained antibodies with a corresponding autoantibody activity which could be removed by prior incubation with their complexed antigen. The presence of these AAb's and their formation of CIC may indicate their role in initiating a primary immunological insult to the kidney.     

Immune complexes and Pseudomonas aeruginosa antibodies in cystic fibrosis.

Serum samples from 57 patients with cystic fibrosis were tested for the presence of IgG, IgA, IgM, IgE, and circulating immune complexes containing IgG, IgA, and IgM. Titres of class specific antibodies to Pseudomonas aeruginosa, and class specific antibodies to Ps aeruginosa in circulating immune complexes, were also measured. According to the Shwachman score the patients were divided into three clinical groups: group 1-moderate and severe disease, group 2-mild disease, and group 3-well. The results of the immunological investigations were correlated with the clinical state of the patients as assessed by the Shwachman score. Serum concentrations of IgG, IgA, and IgM were inversely correlated with the Shwachman score, but the differences between the groups were only significant for IgG and IgA. The same correlations were found for circulating immune complexes containing IgG and IgA. Antibodies to Ps aeruginosa could be detected in most of the patients'' serum samples. IgA antibody specific to Ps aeruginosa was the most often raised, even in patients in group 3. It is therefore suggested that IgA antibody specific to Ps aeruginosa could be an early marker of colonisation by Ps aeruginosa and a sensitive measurement of infection with Ps aeruginosa in young children with cystic fibrosis. Moreover, in the circulating immune complexes, class specific antibodies to Ps aeruginosa were found in nearly half the patients. The highest titres of IgG and IgA antibodies specific to Ps aeruginosa in the circulating immune complexes were detected in the patients with the worst clinical state (group 1).     

Agenesis of the Corpus Callosum and Neural Crest Tumors

Hematologic abnormalities, including thrombocytopenia, are seen in HIV infection. Mi have previously reported elevated platelet-associated IgG (PAIgG) in thrombocytopenia in children associated with human immunodeficiency virus (HIV). In this study we prospectively monitored 40 HIV-infected infants and children to determine the significance of elevated PAIgG levels as they relate to thrombocytopenia. We also examined platelet eluatesfor the presence of HIV antibody and antigen. Of 16 patients with thrombocytopenia, 15 (93.7%) had elevated PAIgG. Of 24 patients with normal platelet counts, 21 (87.5%) had elevated PAIgG. On follow-up, none of the children with normal platelet counts and elevated PAIgG levels developed thrombocytopenia. Examination of the platelet eluates was negative for HIV antibody or P24 antigen. Although the sensitivity of an elevated PAIgG level in predicting thrombocytopenia is 93%, its specificity is only 13%. Elevated PAIgG levels are therefore not causally related to the development of thrombocytopenia in children.     

Platelet-Associated IgG in Pediatric HIV Infection

Hematologic abnormalities, including thrombocytopenia, are seen in HIV infection. Mi have previously reported elevated platelet-associated IgG (PAIgG) in thrombocytopenia in children associated with human immunodeficiency virus (HIV). In this study we prospectively monitored 40 HIV-infected infants and children to determine the significance of elevated PAIgG levels as they relate to thrombocytopenia. We also examined platelet eluatesfor the presence of HIV antibody and antigen. Of 16 patients with thrombocytopenia, 15 (93.7%) had elevated PAIgG. Of 24 patients with normal platelet counts, 21 (87.5%) had elevated PAIgG. On follow-up, none of the children with normal platelet counts and elevated PAIgG levels developed thrombocytopenia. Examination of the platelet eluates was negative for HIV antibody or P24 antigen. Although the sensitivity of an elevated PAIgG level in predicting thrombocytopenia is 93%, its specificity is only 13%. Elevated PAIgG levels are therefore not causally related to the development of thrombocytopenia in children.     

Quantitation of renal antigen excretion in the urine of normal children and of children with various renal diseases. I. Quantitation of renal antigens in random urine samples.

This study reports a serologic method for the measurement of kidney-derived antigens in the urine of healthy children and of children with renal diseases. Two hundred twenty patients were studied. Four groups were recognized: group A, patients with no evidence of renal disease; group B, patients with past history of active urinary tract infection; group C, patients with active urinary tract infection; group D, patients with other renal diseases. Urinary renal antigen concentration was tested by the complement fixation method, in which titers of antigens in the urine were compared with a standard human renal antigen extract. The distribution of renal antigen concentrations in group C differed significantly (P(X2Y less than 0.001) from the other three groups. About 85% of patients in groups A, B, and D had levels below 0.6 mg/ml, whereas in group C only 53% of patients had similar concentrations. After factoring the results by the urinary concentration of creatinine, 85% of patients in group C had antigen levels above 0.6 mg/ml as opposed to 24%, 44%, and 27% in groups A, B, and D, respectively. The results of the study are consistent with the assumption that the rate of discharge of renal antigenic material in the urine is accelerated in certain renal diseases.     

Shunt nephritis: the nature of the serum cryoglobulins and their relation to the complement profile.

The serum complement profiles of four patients with shunt nephritis indicated classical pathway activation of the complement system. The presence of mixed cryoglobulins was correlated with disease activity and the cryoglobulins were shown to be complement reactive. Antisera to two of the cryoglobulins recognized antigens of the infecting organism, and a specific bacterial antibody was identified in one cryoglobulin, giveing evidence that the cryoglobulins contained immune complexes. Bacterial antibody without detectable antigen was demonstrable in the sera indicating antibody excess. Renal morphology demonstrated mesangial proliferation and interposition with subendothelial and mesangial deposits. Parallels are drawn with active lupus nephritis.     

Immunological findings in patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) and their family members: are heterozygotes subclinically affected?

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED; APS-1) is an autosomal recessive autoimmune disease, caused by mutations in the AIRE (autoimmune regulator) gene. Due to the proposed role of AIRE in central immune tolerance, the immune investigation of four females diagnosed with APECED, their siblings, parents and 14 age-matched controls was performed. The parameters analyzed included immunoglobulins, autoantibodies, cellular immunity and production of cytokines IFNgamma, IL-4 and IL-10, reflecting Th1xTh2 balance. Low IFNgamma levels (455 +/- 191 pg/ml) were detected in all affected girls compared to controls (910 +/- 406 pg/ml). Two girls with homozygous R257X mutations showed similarly marked elevation of IgM and increase of CD3+CD4+ lymphocytes. Positive autoantibodies against smooth muscle were found in one affected girl; another girl and her mother had antibodies against gastric parietal cells. Interestingly, all fathers had dramatically elevated levels of IgA and activated T lymphocytes. High frequency of abnormal immune results among parents is a novel finding which might suggest a subclinical immune deficit in heterozygotes with AIRE mutations.     

Nephrotic syndrome associated with varicella infection

A 4-year-old boy developed nephrotic syndrome following varicella infection. Serologic studies during the early phase of the disease demonstrated a decrease in serum C3, C4, and properdin factor B. Renal biopsy revealed an acute proliferative glomerulonephritis with deposition of immunoglobulins A (IgA) and M, C3, C1q, and varicella virus antigen in the glomerulus, suggesting an immune complex deposition. Ultrastructurally, this suggested a postinfectious immune complex glomerulonephritis. These phenomena suggested that varicella virus antigen antibody complexes were deposited in the glomerulus and activated the classic and alternative pathway of complements, leading to an immune complex glomerulonephritis. During the nephrotic phase, an increase in OKT8 cells and decrease of the OKT4 cells were demonstrated. Two months later, this alteration returned to normal as the renal disease was in remission. This change of lymphocyte subsets during varicella infection may play a role in the pathogenesis of nephrotic syndrome.