Disease-associated CTNNBL1 mutation impairs somatic hypermutation by decreasing nuclear AID

Patients with common variable immunodeficiency associated with autoimmune cytopenia (CVID+AIC) generate few isotype-switched B cells with severely decreased frequencies of somatic hypermutations (SHMs), but their underlying molecular defects remain poorly characterized. We identified a CVID+AIC patient who displays a rare homozygous missense M466V mutation in β-catenin-like protein 1 (CTNNBL1). Because CTNNBL1 binds activation-induced cytidine deaminase (AID) that catalyzes SHM, we tested AID interactions with the CTNNBL1 M466V variant. We found that the M466V mutation interfered with the association of CTNNBL1 with AID, resulting in decreased AID in the nuclei of patient EBV-transformed B cell lines and of CTNNBL1 466V/V Ramos B cells engineered to express only CTNNBL1 M466V using CRISPR/Cas9 technology. As a consequence, the scarce IgG+ memory B cells from the CTNNBL1 466V/V patient showed a low SHM frequency that averaged 6.7 mutations compared with about 18 mutations per clone in healthy-donor counterparts. In addition, CTNNBL1 466V/V Ramos B cells displayed a decreased incidence of SHM that was reduced by half compared with parental WT Ramos B cells, demonstrating that the CTNNBL1 M466V mutation is responsible for defective SHM induction. We conclude that CTNNBL1 plays an important role in regulating AID-dependent antibody diversification in humans.

Case Report: Secondary Hemophagocytic Lymphohistiocytosis With Disseminated Infection in Chronic Granulomatous Disease-A Serious Cause of Mortality

Chronic granulomatous disease (CGD) is a primary immune deficiency due to defects in phagocyte respiratory burst leading to severe and life-threatening infections. Patients with CGD also suffer from disorders of inflammation and immune dysregulation including colitis and granulomatous lung disease, among others. Additionally, patients with CGD may be at increased risk of systemic inflammatory disorders such as hemophagocytic lymphohistiocytosis (HLH). The presentation of HLH often overlaps with symptoms of systemic inflammatory response syndrome (SIRS) or sepsis and therefore can be difficult to identify, especially in patients with a primary immune deficiency in which incidence of infection is increased. Thorough evaluation and empiric treatment for bacterial and fungal infections is necessary as HLH in CGD is almost always secondary to infection. Simultaneous treatment of infection with anti-microbials and inflammation with immunosuppression may be needed to blunt the hyperinflammatory response in secondary HLH. Herein, we present a series of X-linked CGD patients who developed HLH secondary to or with concurrent disseminated CGD-related infection. In two patients, CGD was a known diagnosis prior to development of HLH and in the other two CGD was diagnosed as part of the evaluation for HLH. Concurrent infection and HLH were fatal in three; one case was successfully treated, ultimately receiving hematopoietic stem cell transplantation. The current literature on presentation, diagnosis, and treatment of HLH in CGD is reviewed.

Lentiviral hematopoietic stem cell gene therapy for X-linked severe combined immunodeficiency

X-linked severe combined immunodeficiency (SCID-X1) is a profound deficiency of T, B, and natural killer (NK) cell immunity caused by mutations inIL2RGencoding the common chain (γc) of several interleukin receptors. Gamma-retroviral (γRV) gene therapy of SCID-X1 infants without conditioning restores T cell immunity without B or NK cell correction, but similar treatment fails in older SCID-X1 children. We used a lentiviral gene therapy approach to treat five SCID-X1 patients with persistent immune dysfunction despite haploidentical hematopoietic stem cell (HSC) transplant in infancy. Follow-up data from two older patients demonstrate that lentiviral vector γc transduced autologous HSC gene therapy after nonmyeloablative busulfan conditioning achieves selective expansion of gene-marked T, NK, and B cells, which is associated with sustained restoration of humoral responses to immunization and clinical improvement at 2 to 3 years after treatment. Similar gene marking levels have been achieved in three younger patients, albeit with only 6 to 9 months of follow-up. Lentiviral gene therapy with reduced-intensity conditioning appears safe and can restore humoral immune function to posthaploidentical transplant older patients with SCID-X1.

Outcomes after Allogeneic Transplant in Patients with Wiskott-Aldrich Syndrome

/kg (range, .3 to 7.9). The median times to neutrophil and platelet engraftment were 19 days (range, 13 to 27) and 18.5 days (range, 12 to 31), respectively. The rate of overall survival was 92% with median follow-up of 67 months (range, 3 to 146). Two patients developed grade IV acute graft-versus-host disease, and 1 died on day +99. Five of 12 patient's (42%) had mixed donor chimerism (range, 12% to 85%) at day +180. None of the pretransplant patient parameters was predictive of mixed chimerism. Nonetheless, of these 5 patients, 2 had normalization of the platelet count despite the mixed chimerism, 2 had full donor chimerism after receiving a second transplant with the same donor, and 1 remains transfusion dependent awaiting a second transplant. Hence, even with a significant rate of mixed chimerism, HSCT provides substantial benefit to WAS patients, with excellent overall survival.

Novel Combined Immune Deficiency and Radiation Sensitivity Blended Phenotype in an Adult with Biallelic Variations in ZAP70 and RNF168

With the advent of high-throughput genomic sequencing techniques, novel genetic etiologies are being uncovered for previously unexplained Mendelian phenotypes, and the underlying genetic architecture of disease is being unraveled. Although most of these “mendelizing” disease traits represent phenotypes caused by single-gene defects, a percentage of patients have blended phenotypes caused by pathogenic variants in multiple genes. We describe an adult patient with susceptibility to bacterial, herpesviral, and fungal infections. Immunologic defects included CD8⁺ T cell lymphopenia, decreased T cell proliferative responses to mitogens, hypogammaglobulinemia, and radiation sensitivity. Whole-exome sequencing revealed compound heterozygous variants in ZAP70. Biallelic mutations in ZAP70 are known to produce a spectrum of immune deficiency that includes the T cell abnormalities observed in this patient. Analyses for variants in genes associated with radiation sensitivity identified the presence of a homozygous RNF168 variant of unknown significance. RNF168 deficiency causes radiosensitivity, immunodeficiency, dysmorphic features, and learning difficulties syndrome and may account for the radiation sensitivity. Thus, the patient was found to have a novel blended phenotype associated with multilocus genomic variation: i.e., separate and distinct genetic defects. These findings further illustrate the clinical utility of applying genomic testing in patients with primary immunodeficiency diseases.

Primary immunodeficiency diseases: Genomic approaches delineate heterogeneous Mendelian disorders

BACKGROUND

Primary immunodeficiency diseases (PIDDs) are clinically and genetically heterogeneous disorders thus far associated with mutations in more than 300 genes. The clinical phenotypes derived from distinct genotypes can overlap. Genetic etiology can be a prognostic indicator of disease severity and can influence treatment decisions.

OBJECTIVE

We sought to investigate the ability of whole-exome screening methods to detect disease-causing variants in patients with PIDDs.

METHODS

Patients with PIDDs from 278 families from 22 countries were investigated by using whole-exome sequencing. Computational copy number variant (CNV) prediction pipelines and an exome-tiling chromosomal microarray were also applied to identify intragenic CNVs. Analytic approaches initially focused on 475 known or candidate PIDD genes but were nonexclusive and further tailored based on clinical data, family history, and immunophenotyping.

RESULTS

A likely molecular diagnosis was achieved in 110 (40%) unrelated probands. Clinical diagnosis was revised in about half (60/110) and management was directly altered in nearly a quarter (26/110) of families based on molecular findings. Twelve PIDD-causing CNVs were detected, including 7 smaller than 30 Kb that would not have been detected with conventional diagnostic CNV arrays.

CONCLUSION

This high-throughput genomic approach enabled detection of disease-related variants in unexpected genes; permitted detection of low-grade constitutional, somatic, and revertant mosaicism; and provided evidence of a mutational burden in mixed PIDD immunophenotypes.

Adoptive immunotherapy for primary immunodeficiency disorders with virus-specific T lymphocytes

BACKGROUND

Viral infections are a leading fatal complication for patients with primary immunodeficiencies (PIDs) who require hematopoietic stem cell transplantation (HSCT). Use of virus-specific T lymphocytes (VSTs) has been successful for the treatment and prevention of viral infections after HSCT for malignant and nonmalignant conditions. Here we describe the clinical use of VSTs in patients with PIDs at 4 centers.

OBJECTIVE

We sought to evaluate the safety and efficacy of VSTs for treatment of viral infections in patients with PIDs.

METHODS

Patients with PIDs who have received VST therapy on previous or current protocols were reviewed in aggregate. Clinical information, including transplantation details, viral infections, and use of antiviral and immunosuppressive pharmacotherapy, were evaluated. Data regarding VST production, infusions, and adverse reactions were compared.

RESULTS

Thirty-six patients with 12 classes of PID diagnoses received 37 VST products before or after HSCT. Twenty-six (72%) patients had received a diagnosis of infection with cytomegalovirus, EBV, adenovirus, BK virus, and/or human herpesvirus 6. Two patients were treated before HSCT because of EBV-associated lymphoproliferative disease. Partial or complete responses against targeted viruses occurred in 81% of patients overall. Time to response varied from 2 weeks to 3 months (median, 28 days). Overall survival at 6 months after therapy was 80%. Four patients had graft-versus-host disease in the 45 days after VST infusion, which in most cases was therapy responsive.

CONCLUSION

VSTs derived from either stem cell donors or third-party donors are likely safe and effective for the treatment of viral infections in patients with PIDs.

Vaccine-associated varicella and rubella infections in severe combined immunodeficiency with isolated CD4 lymphocytopenia and mutations in IL7R detected by tandem whole exome sequencing and chromosomal microarray

In areas without newborn screening for severe combined immunodeficiency (SCID), disease-defining infections may lead to diagnosis, and in some cases, may not be identified prior to the first year of life. We describe a female infant who presented with disseminated vaccine-acquired varicella (VZV) and vaccine-acquired rubella infections at 13 months of age. Immunological evaluations demonstrated neutropenia, isolated CD4 lymphocytopenia, the presence of CD8(+) T cells, poor lymphocyte proliferation, hypergammaglobulinaemia and poor specific antibody production to VZV infection and routine immunizations. A combination of whole exome sequencing and custom-designed chromosomal microarray with exon coverage of primary immunodeficiency genes detected compound heterozygous mutations (one single nucleotide variant and one intragenic copy number variant involving one exon) within the IL7R gene. Mosaicism for wild-type allele (20-30%) was detected in pretransplant blood and buccal DNA and maternal engraftment (5-10%) demonstrated in pretransplant blood DNA. This may be responsible for the patient's unusual immunological phenotype compared to classical interleukin (IL)-7Rα deficiency. Disseminated VZV was controlled with anti-viral and immune-based therapy, and umbilical cord blood stem cell transplantation was successful. Retrospectively performed T cell receptor excision circle (TREC) analyses completed on neonatal Guthrie cards identified absent TREC. This case emphasizes the danger of live viral vaccination in severe combined immunodeficiency (SCID) patients and the importance of newborn screening to identify patients prior to high-risk exposures. It also illustrates the value of aggressive pathogen identification and treatment, the influence newborn screening can have on morbidity and mortality and the significant impact of newer genomic diagnostic tools in identifying the underlying genetic aetiology for SCID patients.

Newborn screening for severe combined immunodeficiency in 11 screening programs in the United States

IMPORTANCE

Newborn screening for severe combined immunodeficiency (SCID) using assays to detect T-cell receptor excision circles (TRECs) began in Wisconsin in 2008, and SCID was added to the national recommended uniform panel for newborn screened disorders in 2010. Currently 23 states, the District of Columbia, and the Navajo Nation conduct population-wide newborn screening for SCID. The incidence of SCID is estimated at 1 in 100,000 births.

OBJECTIVES

To present data from a spectrum of SCID newborn screening programs, establish population-based incidence for SCID and other conditions with T-cell lymphopenia, and document early institution of effective treatments.

DESIGN

Epidemiological and retrospective observational study.

SETTING

Representatives in states conducting SCID newborn screening were invited to submit their SCID screening algorithms, test performance data, and deidentified clinical and laboratory information regarding infants screened and cases with nonnormal results. Infants born from the start of each participating program from January 2008 through the most recent evaluable date prior to July 2013 were included. Representatives from 10 states plus the Navajo Area Indian Health Service contributed data from 3,030,083 newborns screened with a TREC test.

MAIN OUTCOMES AND MEASURES

Infants with SCID and other diagnoses of T-cell lymphopenia were classified. Incidence and, where possible, etiologies were determined. Interventions and survival were tracked.

RESULTS

Screening detected 52 cases of typical SCID, leaky SCID, and Omenn syndrome, affecting 1 in 58,000 infants (95% CI, 1/46,000-1/80,000). Survival of SCID-affected infants through their diagnosis and immune reconstitution was 87% (45/52), 92% (45/49) for infants who received transplantation, enzyme replacement, and/or gene therapy. Additional interventions for SCID and non-SCID T-cell lymphopenia included immunoglobulin infusions, preventive antibiotics, and avoidance of live vaccines. Variations in definitions and follow-up practices influenced the rates of detection of non-SCID T-cell lymphopenia.

CONCLUSIONS AND RELEVANCE

Newborn screening in 11 programs in the United States identified SCID in 1 in 58,000 infants, with high survival. The usefulness of detection of non-SCID T-cell lymphopenias by the same screening remains to be determined.

Next generation sequencing reveals skewing of the T and B cell receptor repertoires in patients with wiskott-Aldrich syndrome

The Wiskott–Aldrich syndrome (WAS) is due to mutations of the WAS gene encoding for the cytoskeletal WAS protein, leading to abnormal downstream signaling from the T cell and B cell antigen receptors (TCR and BCR). We hypothesized that the impaired signaling through the TCR and BCR in WAS would subsequently lead to aberrations in the immune repertoire of WAS patients. Using next generation sequencing (NGS), the T cell receptor β and B cell immunoglobulin heavy chain (IGH) repertoires of eight patients with WAS and six controls were sequenced. Clonal expansions were identified within memory CD4⁺ cells as well as in total, naïve and memory CD8⁺ cells from WAS patients. In the B cell compartment, WAS patient IGH repertoires were also clonally expanded and showed skewed usage of IGHV and IGHJ genes, and increased usage of IGHG constant genes, compared with controls. To our knowledge, this is the first study that demonstrates significant abnormalities of the immune repertoire in WAS patients using NGS.

Somatic reversion in dedicator of cytokinesis 8 immunodeficiency modulates disease phenotype

BACKGROUND

Autosomal recessive loss-of-function mutations in dedicator of cytokinesis 8 (DOCK8) cause a combined immunodeficiency characterized by atopy, recurrent infections, and cancer susceptibility. A genotype-phenotype explanation for the variable disease expression is lacking.

OBJECTIVE

We investigated whether reversions contributed to the variable disease expression.

METHODS

Patients followed at the National Institutes of Health's Clinical Center were studied. We performed detailed genetic analyses and intracellular flow cytometry to detect DOCK8 protein expression within lymphocyte subsets.

RESULTS

We identified 17 of 34 DOCK8-deficient patients who had germline mutations with variable degrees of reversion caused by somatic repair. Somatic repair of the DOCK8 mutations resulted from second-site mutation, original-site mutation, gene conversion, and intragenic crossover. Higher degrees of reversion were associated with recombination-mediated repair. DOCK8 expression was restored primarily within antigen-experienced T cells or natural killer cells but less so in naive T or B cells. Several patients exhibited multiple different repair events. Patients who had reversions were older and had less severe allergic disease, although infection susceptibility persisted. No patients were cured without hematopoietic cell transplantation.

CONCLUSIONS

In patients with DOCK8 deficiency, only certain combinations of germline mutations supported secondary somatic repair. Those patients had an ameliorated disease course with longer survival but still had fatal complications or required hematopoietic cell transplantation. These observations support the concept that some DOCK8-immunodeficient patients have mutable mosaic genomes that can modulate disease phenotype over time.

Robust T cell responses to aspergillosis in chronic granulomatous disease: implications for immunotherapy

Chronic granulomatous disease (CGD) patients are highly susceptible to invasive aspergillosis and might benefit from aspergillus-specific T cell immunotherapy, which has shown promise in treating those with known T cell defects such as haematopoietic stem cell transplant (HSCT) recipients. But whether such T cell defects contribute to increased risks for aspergillus infection in CGD is unclear. Hence, we set out to characterize the aspergillus-specific T cell response in CGD. In murine CGD models and in patients with CGD we showed that the CD4(+) T cell responses to aspergillus were unimpaired: aspergillus-specific T cell frequencies were even elevated in CGD mice (P < 0·01) and humans (P = 0·02), compared to their healthy counterparts. CD4-depleted murine models suggested that the role of T cells might be redundant because resistance to aspergillus infection was conserved in CD4(+) T cell-depleted mice, similar to wild-type animals. In contrast, mice depleted of neutrophils alone or neutrophils and CD4(+) T cells developed clinical and pathological evidence of pulmonary aspergillosis and increased mortality (P < 0·05 compared to non-depleted animals). Our findings that T cells in CGD have a robust aspergillus CD4(+) T cell response suggest that CD4(+) T cell-based immunotherapy for this disease is unlikely to be beneficial.

Rapid genetic analysis of x-linked chronic granulomatous disease by high-resolution melting

High-resolution melting analysis was applied to X-linked chronic granulomatous disease, a rare disorder resulting from mutations in CYBB. Melting curves of the 13 PCR products bracketing CYBB exons were predicted by Poland's algorithm and compared with observed curves from 96 normal individuals. Primer plates were prepared robotically in batches and dried, greatly simplifying the 3- to 6-hour workflow that included DNA isolation, PCR, melting, and cycle sequencing of any positive products. Small point mutations or insertions/deletions were detected by mixing the hemizygous male DNA with normal male DNA to produce artificial heterozygotes, whereas detection of gross deletions was performed on unmixed samples. Eighteen validation samples and 22 clinical kindreds were analyzed for CYBB mutations. All blinded validation samples were correctly identified. The clinical probands were identified after screening for neutrophil oxidase activity. Nineteen different mutations were found, including seven near intron-exon boundaries predicting splicing defects, five substitutions within exons, three small deletions predicting premature termination, and four gross deletions of multiple exons. Ten novel mutations were found, including (c.) two missense (730T>A, 134T>G), one nonsense (90C>A), four splice site defects (45 + 1G>T, 674 + 4A>G, 1461 + 2delT, and 1462-2A>C), two small deletions (636delT, 1661_1662delCT), and one gross deletion of exons 6 to 8. High-resolution melting can provide timely diagnosis at low cost for effective clinical management of rare, genetic primary immunodeficiency disorders.

Vaccine-acquired rotavirus in infants with severe combined immunodeficiency

Live pentavalent human-bovine reassortant rotavirus vaccine is recommended in the United States for routine immunization of infants. We describe three infants, two with failure to thrive, who had dehydration and diarrhea within 1 month after their first or second rotavirus immunization and subsequently received a diagnosis of severe combined immunodeficiency. Rotavirus was detected, by means of reverse-transcriptase-polymerase-chain-reaction (RT-PCR) assay, in stool specimens obtained from all three infants, and gene-sequence analysis revealed the presence of vaccine rotavirus. These infections raise concerns regarding the safety of rotavirus vaccine in severely immunocompromised patients.

Outcomes of patients with severe combined immunodeficiency treated with hematopoietic stem cell transplantation with and without preconditioning

BACKGROUND

The effect of pretransplantation conditioning on the long-term outcomes of patients receiving hematopoietic stem cell transplantation for severe combined immunodeficiency (SCID) has not been completely determined.

OBJECTIVE

We sought to assess the outcomes of 23 mostly conditioned patients with SCID and compare their outcomes with those of 25 previously reported nonconditioned patients with SCID who underwent transplantation.

METHODS

In the present study we reviewed the medical records of these 23 consecutive, mostly conditioned patients with SCID who underwent transplantation between 1998 and 2007.

RESULTS

Eighteen patients (median age at transplantation, 10 months; range, 0.8-108 months) received haploidentical mismatched related donor, matched unrelated donor, or mismatched unrelated donor transplants, 17 of whom received pretransplantation conditioning (with 1 not conditioned); 13 (72%) patients engrafted with donor cells and survive at a median of 3.8 years (range, 1.8-9.8 year); 5 (38%) of 13 patients require intravenous immunoglobulin; and 6 of 6 age-eligible children attend school. Of 5 recipients (median age at transplantation, 7 months; range, 2-23 months) of matched related donor transplants, all 5 engrafted and survive at a median of 7.5 years (range, 1.5-9.5 year), 1 recipient requires intravenous immunoglobulin, and 3 of 3 age-eligible children attend school. Gene mutations were known in 16 cases: mutation in the common gamma chain of the IL-2 receptor (IL2RG) in 7 patients, mutation in the alpha chain of the IL-7 receptor (IL7RA) in 4 patients, mutation in the recombinase-activating gene (RAG1) in 2 patients, adenosine deaminase deficiency (ADA) in 2 patients, and adenylate kinase 2 (AK2) in 1 patient. Early outcomes and quality of life of the previous nonconditioned versus the present conditioned cohorts were not statistically different, but longer-term follow-up is necessary for confirmation.

CONCLUSIONS

Hematopoietic stem cell transplantation in patients with SCID results in engraftment, long-term survival, and a good quality of life for the majority of patients with or without pretransplantation conditioning.

Mumps resurgence in the United States

The recent mumps epidemic in the central United States has generated a large amount of public concern. A total of 2597 mumps cases have been reported in the United States in 11 states since January 1, 2006, representing a marked resurgence of mumps in a single year. The majority of these recent cases have occurred in college students age 18 to 25 years. Most were vaccinated with 2 doses of measles, mumps, and rubella-containing vaccines. Such outbreaks provide an opportunity for clinicians to review the clinical presentation, diagnosis, and morbidity of vaccine-preventable infections and also to review immunologic mechanisms and practice guidelines that might contribute to poor vaccine responses. A review of mumps is provided with discussion of potential mechanisms for vaccine failure.

Mechanistic actions of the risks and adverse events associated with vaccine administration

Vaccine-preventable disease levels in the United States are at or near record lows. Most parents today have never seen a case of diphtheria, measles, or other once commonly encountered infectious diseases now preventable by vaccine administration. As a result, some parents wonder why their children must receive shots for diseases that do not seem to exist. Myths and misinformation about vaccine safety abound and can confuse parents who are trying to make sound decisions about their children's health care. However, we cannot take continued high immunization coverage levels for granted. A successful vaccination program, like a successful society, depends on the cooperation of every individual to ensure the good of all. This review outlines for clinical allergists-immunologists the molecular basis for the risks and adverse events associated with vaccine administration so that they can be better informed as experts on vaccine-associated adverse reactions.

29. Immunization

The medical dictionary defines immunization as the "protection of susceptible individuals from communicable diseases by the administration of a living modified agent, a suspension of killed organisms, or an inactivated toxin." This elegant description can be expanded to include twenty-first century approaches to immunization that include recombinant technology, reassortment virus techniques, live vectors, DNA vaccines, and the expansion of the field to encompass noncommunicable diseases such as Alzheimer's disease, autoimmunity, and tumor immunogenetics. Integral to the success of immunization is our knowledge of the immune system's memory of antigens, yet our understanding of this fundamental feature remains limited. On a global scale, communicable diseases remain the number-one cause of morbidity and mortality; hence Jenner's pioneering work with its birth in 1796 still has a challenging and exciting future.

Combination antiretroviral strategies for the treatment of pregnant HIV-1-infected women and prevention of perinatal HIV-1 transmission

CONTEXT

The Women and Infants Transmission Study is a prospective natural history study that has been enrolling HIV-1-infected pregnant women and their infants since 1989.

OBJECTIVE

To evaluate the impact of different antiretroviral regimens on perinatal HIV-1 transmission at the population level.

DESIGN

Prospective cohort study. Plasma HIV-1 RNA levels were serially measured in 1542 HIV-1-infected women with singleton live births between January 1990 and June 2000.

MAIN OUTCOME MEASURE

HIV-1 status of the infant.

RESULTS

HIV-1 transmission was 20.0% (95% confidence interval [CI], 16.1%-23.9%) for 396 women who not receiving prenatal antiretroviral therapy; 10.4% (95% CI, 8.2%-12.6%) for 710 receiving zidovudine monotherapy; 3.8% (95% CI, 1.1%-6.5%) for 186 receiving dual antiretroviral therapy with no or one highly active drug (Multi-ART); and 1.2% (95% CI, 0-2.5%) for 250 receiving highly active antiretroviral therapy (HAART). Transmission also varied by maternal delivery HIV RNA level: 1.0% for <400; 5.3% for 400 to 3499; 9.3% for 3500 to 9999; 14.7% for 10,000 to 29,999; and 23.4% for >30,000 copies/mL (p =.0001 for trend). The odds of transmission increased 2.4-fold (95% CI, 1.7-3.5) for every log10 increase in delivery viral load. In multivariate analyses adjusting for maternal viral load, duration of therapy, and other factors, the odds ratio for transmission for women receiving Multi-ART and HAART compared with those receiving ZDV monotherapy was 0.30 (95% CI, 0.09-1.02) and 0.27 (95% CI, 0.08-0.94), respectively.

CONCLUSION

Levels of HIV-1 RNA at delivery and prenatal antiretroviral therapy were independently associated with transmission. The protective effect of therapy increased with the complexity and duration of the regimen. HAART was associated with the lowest rates of transmission.

Mother-to-child transmission of the human immunodeficiency virus in Texas

BACKGROUND

The Pediatric Spectrum of HIV Diseases (PSD) project has been collecting data on HIV-exposed children in Texas since 1989. These data have now been analyzed to describe mother-to-child transmission in Texas and to provide much needed information on the magnitude of the pediatric HIV epidemic in the state.

METHODS

We examined trends in the numbers of perinatally exposed children and perinatally acquired cases of HIV in the Texas PSD cohort. We calculated transmission rates and relative risks for 656 children born from January, 1995, to July, 1998, that received all or part of the ACTG 076 regimen.

RESULTS

Only a small proportion (38%) of pairs of an HIV-infected mother and her HIV-exposed child received the full AIDS Clinical Trial Group 076 (ACTG 076) regimen; only 73% of the mothers received at least some prenatal care. In recent years, however, the numbers of perinatally exposed children and perinatally acquired cases of HIV have decreased in Texas. Univariate analyses showed that a reduction in the vertical transmission of HIV was associated with receipt of a full ACTG 076 regimen, receipt of a partial ACTG 076 regimen and residence in Dallas County.

CONCLUSIONS

Findings identify a gap in meeting the health care needs of pregnant HIV-infected women and suggest missed opportunities to prevent mother-to-child transmission of HIV. At the same time this study confirms progress in prevention efforts to reduce mother-to-child transmission of HIV in Texas.

Organ-specific manifestations of HIV disease in children

The clinical manifestations of HIV disease in children affect multiple organ systems. The severity of each manifestation varies by organ system and can be related in many cases to multifactorial causes, namely HIV replication in affected tissue, concomitant opportunistic infection of the organ, effect of concurrent immunodeficiency or autoimmune mechanisms on the organ, or adverse end-organ drug effect (primary HIV therapy or prophylaxis regimens). More information is needed to understand the pathogenesis of the systemic effect of HIV on different organ systems, especially the CNS. Most clinicians hope that advances in therapeutic interventions for primary HIV will halt the progression of the organ-specific manifestations that have been outlined in this article, but such potent therapies will probably have their own unique and new effects on HIV-infected organ systems. Vigilance for organ-specific manifestations in the era of HAART is imperative to provide the best clinical outcome for HIV-infected children.

Maternal and infant factors predicting disease progression in human immunodeficiency virus type 1-infected infants. Women and Infants Transmission Study Group

BACKGROUND

Infants with perinatally acquired human immunodeficiency virus type 1 (HIV-1) infection have widely variable courses. Previous studies showed that a number of maternal and infant factors, when analyzed separately, are associated with infant HIV-1 disease progression. In this study, clincal, virologic, and immunologic characteristics in the mothers and infants were examined together to determine the predictors of disease progression by 18 months of age and the associations with rapid progression during the first 6 months of life.

METHODS

One hundred twenty-two HIV-1-infected women whose infants were HIV-1 infected were identified from the Women and Infants Transmission Study (WITS) cohort. WITS is a longitudinal natural history study of perinatal HIV-1 infection carried out in 6 sites in the continental United States and in Puerto Rico. The women were enrolled during pregnancy and their infants were enrolled at the time of delivery and followed prospectively by a standardized protocol. Virologic and immunologic studies were performed in laboratories certified by National Institutes of Health-sponsored quality assurance programs. Maternal factors in pregnancy were used as potential predictors of infant disease progression (progression to Centers for Disease Control and Prevention [CDC] Clinical Class C disease or death by 18 months of age) or as correlates of progression at <6 months of age. Infant factors defined during the first 6 months of life were used as potential predictors of progression during 6 to 18 months of age and as correlates of progression at <6 months of age.

RESULTS

Progression by 18 months of age occurred in 32% of infants and by 6 months of age in 15%. Maternal characteristics that, by univariate analysis, were significant predictors of infant disease progression by 18 months of age were elevated viral load, depressed CD4(+)%, and depressed vitamin A. CD8(+)%, CD8(+) activation markers, zidovudine (ZDV) use, hard drug use, and gestational age at delivery were not. When examined in a combined multivariate analysis of maternal characteristics, only vitamin A concentration independently predicted infant progression. Infant characteristics during the first 6 months of life that, by univariate analysis, were associated with disease progression included elevated mean viral load at 1 to 6 months of age, depressed CD4(+)%, CDC Clinical Disease Category B, and growth delay. Early HIV-1 culture positivity (<48 hours), CD8(+)%, CD8(+) activation markers, and ZDV use during the first month of life did not predict progression. Multivariate analysis of infant characteristics showed that the only independent predictors were progression to CDC Category B by 6 months of age (odds ratio [OR], 5.80) and mean viral load from 1 to 6 months of age (OR, 1.99). The final combined maternal and infant analysis included the significant maternal and infant characteristics in a multivariate analysis. It showed that factors independently predicting infant progression by 18 months of age were progression to CDC Category B by 6 months of age (OR, 5.80) and elevated mean HIV-1 RNA copy number at 1 to 6 months of age (OR, 1.99). The characteristics associated with rapid progression to CDC Category C disease or death by 6 months of age were also examined. The only maternal characteristic associated with progression by 6 months in multivariate analysis was low maternal CD4(+)%. The infant characteristics associated with progression by 6 months of age in multivariate analysis were depressed mean CD4(+)% from birth through 2 months and the presence of lymphadenopathy, hepatomegaly, or splenomegaly by 3 months. Infant ZDV use was not assocciated with rapid progression.

CONCLUSION

The strongest predictors of progression by 18 months are the presence of moderate clinical symptoms and elevated RNA copy number in the infants in the first 6 months of life. In contrast, progression by 6 months is associated with maternal and infant immun

Frequent detection of escape from cytotoxic T-lymphocyte recognition in perinatal human immunodeficiency virus (HIV) type 1 transmission: the ariel project for the prevention of transmission of HIV from mother to infant

Host immunologic factors, including human immunodeficiency virus (HIV)-specific cytotoxic T lymphocytes (CTL), are thought to contribute to the control of HIV type 1 (HIV-1) replication and thus delay disease progression in infected individuals. Host immunologic factors are also likely to influence perinatal transmission of HIV-1 from infected mother to infant. In this study, the potential role of CTL in modulating HIV-1 transmission from mother to infant was examined in 11 HIV-1-infected mothers, 3 of whom transmitted virus to their offspring. Frequencies of HIV-1-specific human leukocyte antigen class I-restricted CTL responses and viral epitope amino acid sequence variation were determined in the mothers and their infected infants. Maternal HIV-1-specific CTL clones were derived from each of the HIV-1-infected pregnant women. Amino acid substitutions within the targeted CTL epitopes were more frequently identified in transmitting mothers than in nontransmitting mothers, and immune escape from CTL recognition was detected in all three transmitting mothers but in only one of eight nontransmitting mothers. The majority of viral sequences obtained from the HIV-1-infected infant blood samples were susceptible to maternal CTL. These findings demonstrate that epitope amino acid sequence variation and escape from CTL recognition occur more frequently in mothers that transmit HIV-1 to their infants than in those who do not. However, the transmitted virus can be a CTL susceptible form, suggesting inadequate in vivo immune control.

Lack of tumors in infants with perinatal HIV-1 exposure and fetal/neonatal exposure to zidovudine

Zidovudine (ZDV) therapy during pregnancy and to the neonate reduced perinatal HIV transmission by nearly 70% in Pediatric AIDS Clinical Trials Group (PACTG) protocol 076. ZDV has been reported as positive in several in vitro carcinogenicity screening tests. We evaluated the short-term risk for tumors in 727 children with known ZDV exposure enrolled into the PACTG 076/219 and the Women and Infants Transmission Study (WITS). ZDV exposure in utero (antepartum) occurred in 97% and 99% of infants in PACTG 076/219 or WITS, respectively. Mean follow-up was 38.3 months with 366.9 person years follow-up for PACTG 076/219 and 14.5 months with 743.7 person years follow-up for WITS. No tumors of any nature were observed; relative risk was 0 (95% confidence interval [CI], 0-17.6). These data are reassuring regarding the short-term lack of tumors for ZDV-exposed infants observed to date. Longitudinal, standardized follow-up for infants with in utero antiretroviral exposure is necessary to assess long-term carcinogenicity.

The Ariel Project: A prospective cohort study of maternal-child transmission of human immunodeficiency virus type 1 in the era of maternal antiretroviral therapy

In a prospective cohort study, clinical and biologic factors that contribute to maternal-child transmission of human immunodeficiency virus type 1 (HIV-1) were studied. HIV-infected pregnant women and their infants were evaluated prospectively according to a standardized protocol. Of 204 evaluable women, 81% received zidovudine during their pregnancy. The infection rate among the 209 evaluable infants was 9.1%. By univariate analysis, histologic chorioamnionitis, prolonged rupture of membranes, and a history of genital warts were significantly associated with transmission. Additional factors associated with transmission that approached significance included a higher maternal virus load at delivery and the presence of cocaine in the urine. In a logistic regression model, histologic chorioamnionitis was the only independent predictor of transmission. Despite a significantly higher transmission rate at one site, no unique viral genotype was found at any site. Thus, chorioamnionitis was found to be the major risk factor for transmission among women receiving zidovudine.

Sexual abuse of children: intersection with the HIV epidemic

OBJECTIVE

Sexual transmission of human immunodeficiency virus (HIV) is the predominant risk exposure among adolescents and adults reported with HIV infection and acquired immunodeficiency syndrome (AIDS). Although perinatal transmission accounts for the majority of HIV infection in children, there have been reports of HIV transmission through sexual abuse of children. We characterized children <13 years of age who may have acquired HIV infection through sexual abuse.

METHODS

All reports by state and local health departments to the national HIV/AIDS surveillance system of children with HIV infection not AIDS (n = 1507) and AIDS (n = 7629) through December 1996 were reviewed for history of sexual abuse. Information was ascertained from data recorded on the case report form as well as investigations of children with no risk for HIV infection reported or identified on initial investigation. For children with a possible history of sexual abuse, additional data were collected, including how sexual abuse was diagnosed; characteristics of the perpetrator(s) (ie, HIV status and HIV risks); and other possible risk factors for the child's HIV infection.

RESULTS

Of 9136 children reported with HIV or AIDS, 26 were sexually abused with confirmed (n = 17) or suspected (n = 9) exposure to HIV infection; mean age of these children at diagnosis of HIV infection was 8.8 years (range, 3 to 12 years). There were 14 females and 3 males who had confirmed sexual exposure to an adult male perpetrator at risk for or infected with HIV; of these, 14 had no other risk for HIV infection, and 3 had multiple risks for HIV infection (ie, through sexual abuse, perinatal exposure, and physical abuse through drug injection). The other 9 children (8 females, 1 male) had no other risk factors for HIV infection and were suspected to have been infected through sexual abuse, but the identity, HIV risk, or HIV status of all the perpetrator(s) was not known. All cases of sexual abuse had been reported to local children's protective agencies. Sexual abuse was established on the basis of physician diagnosis or physical examination (n = 20), child disclosure (n = 15), previous or concurrent noncongenital sexually transmitted disease (n = 9), and for confirmed cases, criminal prosecution of the HIV-infected or at-risk perpetrator (n = 8). For the 17 children with confirmed sexual exposure to HIV infection, 19 male perpetrators were identified who were either known to be HIV infected (n = 18) or had risk factors for HIV infection (n = 17), most of whom were a parent or relative.

CONCLUSIONS

These 26 cases highlight the tragic intersection of child sexual abuse and the HIV epidemic. Although the number of reported cases of sexual transmission of HIV infection among children is small, it is a minimum estimate based on population-based surveillance and is an important and likely underrecognized public health problem. Health care providers should consider sexual abuse as a possible means of HIV transmission, particularly among children whose mothers are HIV-antibody negative and also among older HIV-infected children. The intersection of child abuse with the HIV epidemic highlights the critical need for clinicians and public health professionals to be aware of the risk for HIV transmission among children who have been sexually abused, and of guidelines for HIV testing among sexually abused children, and to evaluate and report such cases.

The immunogenicity of Haemophilus influenzae type b conjugate vaccines in children born to human immunodeficiency virus-infected women. Women and Infants Transmission Study Group

BACKGROUND

Immunocompromise caused by HIV-1 infection increases the importance of receipt of routine childhood vaccines to prevent infections such as invasive Haemophilus influenzae type B (Hib) disease. The objectives of the study were to evaluate the immunogenicity of Hib conjugate vaccines among HIV-infected children according to clinical and immunologic disease progression as well as viral load.

METHODS

The concentration of antibody to polyribosylribitol phosphate (PRP) was measured at approximately 9 and 24 months of age in plasma specimens from children of HIV-infected women enrolled in the Women and Infants Transmission Study.

RESULTS

Among 227 children (35 HIV-infected, 192 uninfected) at the 9-month study visit who were known to have received age-appropriate immunization with CRM197 mutant Corynebacterium diphtheriae protein-conjugated Hib vaccine, geometric mean antibody concentrations were lower among HIV-infected children (1.64 microg/ml) than among uninfected children (2.70 microg/ml), although the difference was not statistically significant. Anti-PRP antibody concentrations did not vary significantly among these HIV-infected children with predominantly mild-moderate disease progression according to clinical category, immunologic stage or viral load (P > or = 0.48). The proportion of children with antibody concentrations > or = 1.0 microg/ml did not vary significantly according to HIV infection status (73% uninfected, 74% infected) or, if infected, clinical or immunologic disease progression or viral load. Similar results were obtained among 127 children (17 HIV-infected, 110 uninfected) eligible for analysis at the 24-month study visit. Changes in antibody concentrations over time (between 9 and 24 months of age) did not differ significantly among 10 HIV-infected as compared with 72 uninfected children (P=0.81).

CONCLUSIONS

These results suggest that HIV-infected children with predominantly mild-moderate disease progression respond reasonably well in terms of a quantitative antibody response to Hib conjugate vaccines during the first 2 years of life. Research to further characterize the immune response to Hib conjugate vaccines and to further delineate the "durability" of anti-PRP antibody concentrations beyond 2 years of life should be pursued.

Objective measures of allergic disease in children with human immunodeficiency virus infection

BACKGROUND

Available information suggests that IgE levels are elevated in adults infected with human immunodeficiency virus (HIV), and that increased IgE levels correlate with allergic disease, with decreased CD4 counts, and with a poor prognosis. Data with respect to these factors in children are scant.

OBJECTIVE

We investigated whether serum IgE levels are elevated in children with HIV and, if so, whether the serum IgE level correlates with the degree of immunodeficiency and/or objective indicators of allergic disease.

METHODS

Serum IgE levels, CD4 counts, absolute eosinophil counts, and immediate hypersensitivity skin test (IHST) results were collected from 43 children with symptomatic HIV infection (mean age 7.2 years). Associations between serum IgE levels, CD4 counts, and eosinophil counts were investigated by multiple stepwise linear regression analysis. Data were stratified according to IHST positivity, and analysis of variance was used to compare mean values for age, CD4 counts, IgE levels, and eosinophil counts between the two groups.

RESULTS

Serum IgE values were elevated more than 2 SDs above control age-matched mean values in 17 of 43 patients (40%). IHST results were positive in 12 of 43 patients (28%). CD4 counts were less than 200/mm3 in 17 of 43 patients (40%). Stepwise linear regression failed to demonstrate any correlation between serum IgE levels and either CD4 or eosinophil counts. With data divided into two groups according to IHST results (positive vs negative), analysis of variance failed to reveal significant differences between means for patient age, CD4 counts, IgE levels, or eosinophil counts.

CONCLUSIONS

Our findings confirm that serum IgE levels are increased in children infected with HIV, just as in adults. However, an elevated serum IgE level did not correlate with allergic disease as measured by IHST results and eosinophil counts, nor with the degree of immune dysfunction as approximated by CD4 counts. The mechanism and significance of elevated serum IgE levels remain unclear in children with HIV, and warrant further investigation.

Parental perceptions of barriers to childhood immunization: results of focus groups conducted in an urban population

The current US immunization rates for 2 year olds are approximately half of the goal set for the year 2000. Research studies have focused primarily on the perception of health care providers in the identification of barriers and benefits to childhood immunization. While health care providers are an important part of the immunization delivery process, the perceptions of parents are also important. In this study, qualitative methods were used to explore perceived parental barriers to childhood immunization delivery. Twelve focus groups comprising White, African-American, Hispanic, urban and non-urban people were conducted at a variety of sites, including clinics, churches, schools and work sites. The results indicated that time off from work, access to well-child care and difficulty understanding the complexity of the immunization schedule were seen as barriers to adhering to an immunization schedule. Participants emphasized problems in taking time off from work to get immunizations, sometimes without pay, and expressed fears that doing so would jeopardize promotions and raises. While some of the parental perceptions were similar to those identified in studies of health care providers in the literature, many were not. This study emphasizes the importance of gathering information from parents as well as from health care providers.

Increased vertical transmission of human immunodeficiency virus from hepatitis C virus-coinfected mothers. Women and Infants Transmission Study

To determine if hepatitis C virus (HCV) infection affects vertical transmission of human immunodeficiency virus (HIV), 487 HIV-infected pregnant women in the prospective, multicenter, Women and Infants Transmission Study had HCV antibody (anti-HCV by second-generation ELISA) and HCV RNA (by quantitative polymerase chain reaction) measured in peripartum maternal plasma; 161 (33%) were anti-HCV-positive. HIV vertical transmission occurred from 42 HCV-infected mothers (26.1%) versus 53 HCV-uninfected mothers (16.3%; odds radio [OR], 1.82; P = .01). In a logistic regression model that included maternal drug use, a potential confounder, HCV infection was marginally associated with perinatal HIV transmission (OR, 1.64; P = .05), whereas drug use was not. Women who transmitted HIV had higher levels of HCV RNA (median, 721,254 copies/mL) than those who did not (337,561 copies/mL; P = .01). Maternal HCV infection is associated with increased HIV vertical transmission. Further studies are needed to ascertain if HCV directly affects perinatal HIV transmission or is a marker for another factor, such as maternal drug use.

Early spontaneous abortions and fetal thymic abnormalities in maternal-to-fetal HIV infection

The thymus is thought to play a major role in the immunopathogenesis of human immunodeficiency virus (HIV) infection, particularly in maternal-to-fetal HIV transmission. Characteristic lesions of the HIV-infected thymus include a prominent CD4+ CD8+ T lymphocyte depletion at the corticomedullary junction, the region of the thymus where immune selection occurs. At least threefold excess early spontaneous abortions were noted in a cohort of 124 HIV-infected pregnant women. In these 13 abortuses a very high rate (54%) of HIV vertical transmission was documented, with the thymus gland particularly affected. It is possible that the thymic insult in HIV-infected fetuses contributes to immune rejection of the fetus, possibly by an imbalance of maternal and fetal T1- and T2-type cytokines, known to be important in HIV disease progression. We propose, therefore, that the early spontaneous abortions occurring in HIV-infected pregnant women are due, at least in part, to abnormal immune forces created by HIV infection of the thymus.

Role of placental cytokines and inflammation in vertical transmission of HIV infection

In light of new evidence suggesting that maternal human immunodeficiency virus (HIV) infection produces at least a three-fold increase in the number of early spontaneous abortions, it is important to search for factors that may predispose to fetal wastage. Immunological factors are thought to play an important role in permitting the HLA-disparate fetus to continue to term, despite powerful maternal immune forces capable of rejection. In the context of a heightened incidence of spontaneous abortion in HIV infection, evidence is now accumulating that implicates an imbalance in immune factors in contributing to this fetal loss. Soluble immune factors, such as cytokines, have been suggested as contributing agents to recurrent spontaneous abortions. Inflammatory cytokines-interleukin 1beta, interleukin 6 and tumor necrosis factor alpha-have been measured in isolated placental trophoblastic cells in HIV-infected and non-infected pregnant women in an attempt to explore this hypothesis. These inflammatory cytokines and their messenger RNAs were significantly elevated before and after stimulation in HIV-infected women, supporting the belief that HIV-infected women present their fetuses a milieu of imbalanced immune factors capable of contributing to immunological rejection. In addition, these elevated inflammatory cytokine levels may contribute to HIV disease progression in fetuses by virtue of activation of HIV gene transcription factors similar to what has been demonstrated in in vitro systems. We therefore propose that HIV infection in pregnant women produces an altered state of certain soluble immune factors, which in concert with other immune factor abnormalities, such as loss of immune selection in the fetal thymus, predisposes the fetus to advanced HIV infection and possible spontaneous abortion.

Overlapping epitopes in human immunodeficiency virus type 1 gp120 presented by HLA A, B, and C molecules: effects of viral variation on cytotoxic T-lymphocyte recognition

Human immunodeficiency virus (HIV)-specific cytotoxic T lymphocytes (CTL) are thought to exert immunologic selection pressure in infected persons, yet few data regarding the effects of this constraint on viral sequence variation in vivo, particularly in the highly variable Env protein, are available. In this study, CD8+ HIV type 1 (HIV-1) envelope-specific CTL clones specific for gp120 were isolated from peripheral blood mononuclear cells of four HIV-infected individuals, all of which recognized the same 25-amino-acid (aa) peptide (aa 371 to 395), which is partially contained in the CD4-binding domain of HIV-1 gp120. Fine mapping studies revealed that two of the clones optimally recognized the 9-aa sequence 375 to 383 (SFNCGGEFF), while the two other clones optimally recognized the epitope contained in the overlapping 9-aa sequence 376 to 384 (FNCGGEFFY). Lysis of target cells by the two clones recognizing aa 375 to 383 was restricted by HLA B15 and Cw4, respectively, whereas both clones recognizing aa 376 to 384 were restricted by HLA A29. Sequence variation, relative to the IIIB strain sequence used to identify CTL clones, was observed in autologous viruses in the epitope-containing region in all four subjects. However, poorly recognized autologous sequence variants were predominantly seen for the A29-restricted clones, whereas the clones specific for SFNCGGEFF continued to recognize the predominant autologous sequences. These results suggest that the HLA profile of an individual may not only be important in determining the specificity of CTL recognition but may also affect the ability to recognize virus variants and suppress escape from CTL recognition. These results also identify overlapping viral CTL epitopes which can be presented by HLA A, B, and C molecules.

Immunization prevalence rates for infants in a large urban center: Houston/Harris County, 1993

Immunization prevalence rates in Houston/Harris County for children 18 to 24 months were determined by a prospective immunization survey conducted from January through May 1993. Rates for immunization series were very low for 2-year old children regardless of infant gender, maternal age, maternal education, or immunization provider (public verus private). African-American infants had the lowest likelihood of completing their immunization series. Infants who had received their first immunization within the scheduled time frame were most likely to complete the series. More than 57% of caregivers could not state accurately the immunization status of their children. Barriers to immunizations perceived by caregivers were identified as medical barriers, vaccine cost, and transportation. New goals for infant immunization delivery have been established by the national Comprehensive Children's Immunization Initiative. To meet these goals, large urban centers like Houston/Harris County must use resources through both public and private sectors, ie, networked, confidential immunization tracking system; enhanced and sustained educational efforts; and expansion of vaccine availability.

Association of maternal drug use during pregnancy with maternal HIV culture positivity and perinatal HIV transmission

OBJECTIVE

To evaluate the relationship of drug use with maternal HIV culture positivity at delivery and perinatal HIV transmission.

DESIGN

Multicenter prospective cohort study.

SETTING

Obstetric and pediatric clinics in five cities in the United States.

PARTICIPANTS

Five hundred and thirty HIV-infected pregnant women and their infants.

MAIN OUTCOME MEASURES

Multivariate logistic regression was used to evaluate the association of 'hard drug' use (one or more of the following: cocaine, heroin/opiates, methadone, injecting drug use) assessed by self-report and urine toxicology with positive maternal HIV culture at delivery and perinatal HIV transmission.

RESULTS

Forty-two per cent of women used hard drugs during pregnancy. Increased probability of a positive maternal delivery HIV culture was significantly associated with prenatal hard drug use [odds ratio (OR), 3.08] and maternal cocaine use (OR, 2.98) among HIV-infected women with > 29% CD4+ lymphocytes. After adjusting for maternal culture positivity at delivery, CD4+ lymphocyte percentage and gestational age, significantly greater transmission risk was observed with hard drug use among women with membrane rupture > 4 h.

CONCLUSIONS

On the basis of self-report and urine toxicology, overall maternal hard drug use and cocaine use in the WITS cohort were associated with maternal HIV culture positivity at delivery, and maternal hard drug use was associated with perinatal transmission.

Excess intrauterine fetal demise associated with maternal human immunodeficiency virus infection

A prospective study of transplacental transmission of human immunodeficiency virus (HIV) showed an increased rate of spontaneous fetal demise in HIV-seropositive mothers: 14 losses in 124 pregnancies. HIV was detected in placental and fetal tissues in 7 of 14 by in situ hybridization. The proportion of fetal infection far exceeded the transmission rate of 13% in liveborn babies. No association was seen between fetal transmission and a maternal history of drug abuse or coinfections; mothers with AIDS more often had fetal loss associated with HIV transmission than did asymptomatic mothers. In affected fetuses, HIV was detected in many tissues and was associated with thymic pathology. This suggests that maternal HIV infection increases the risk for pregnancy loss associated with HIV transmission. The possibility that HIV may be fetotoxic, that thymic dysfunction may interfere with pregnancy progression, or that the intrauterine milieu in HIV-seropositive pregnancies may be unfavorable (or a combination of factors) should be considered.

Early detection of HIV in infants: aspects of design and analysis for diagnostic test studies

OBJECTIVE

To review investigations on the early detection of HIV infection in infants to determine adherence to traditional methods of study design and analysis for evaluating new laboratory tests.

DATA SOURCES

A National Library of Medicine (MEDLINE) search was conducted to identify such investigations through 1993. Cited references in identified manuscripts were also considered. The search was restricted to investigations of human subjects and those published in the English language.

STUDY SELECTION

Final inclusion criteria included (1) report of the age and human immunodeficiency virus (HIV) infection status of the subjects at the time of the diagnostic testing, and (2) presentation of data allowing confirmation of presented analyses and additional analyses.

DATA EXTRACTION

Criteria for judging the investigations included (1) whether the criteria used to determine the positive and negative test results were defined; (2) whether the necessary sample size for the study was calculated; (3) whether the patients studied were representative of the patients to whom the test would be applied; (4) whether a gold standard evaluation was performed; (5) whether the outcomes included in the analyses were independent; (6) whether the test characteristics were properly analyzed; and, (7) whether confidence intervals were presented.

DATA SYNTHESIS

An informative presentation of a diagnostic test should include as a minimum the seven criteria listed above. Only 21 of 36 (58%) of the studies incorporated at least three of the criteria.

CONCLUSIONS

There is a wide variation in the manner in which investigations of diagnostic tests are conducted and the results reported. Increased awareness and use of standard study designs and analyses will allow the application of metanalyses. Such analyses will help guide the direction taken for finding and establishing early diagnostic procedures for HIV infection at birth or during infancy.

Sensitivity of immune complex-dissociated p24 antigen testing for early detection of human immunodeficiency virus in infants

Several investigators have suggested that early diagnosis of human immunodeficiency virus (HIV) infection in infants could be accomplished with a modified, more-sensitive, acid-dissociated p24 antigen enzyme-linked immunosorbent assay (ELISA) technique (p24 antigen immune complex dissociation [ICD]). We compared detection of HIV infection by HIV culture, PCR, and p24 antigen ICD assays in 46 infants by using samples collected independently. The detection sensitivity of the p24 antigen ICD assay was 0% with cord blood samples (2 HIV-positive infants), 38% with plasma samples from infants under 3 months of age (8 HIV-positive infants), and 58% overall (12 HIV-positive infants). By contrast, the sensitivities of HIV culture and PCR were 50% for cord blood samples, 75% for plasma samples from infants under 3 months of age, and 83% overall. These results indicate that the p24 antigen ICD does not offer the sensitivity necessary for this assay to be used as an indicator of HIV infection in infants.

Case management of HIV-infected children in Missouri

The early referral of HIV-exposed children and their mothers to coordinated medical and social services has become increasingly important. In July 1989, the Missouri Department of Health initiated the Service Coordination Program to provide individualized referral (case management) for Missouri residents who were reported to have acquired immunodeficiency syndrome (AIDS) or HIV infection. The purpose of the Service Coordination Program is to assist persons in accessing medical and social services. The authors describe the characteristics of the 36 children (18 enrolled in the Service Coordination Program, and 18 not enrolled) reported to the Missouri Department of Health through September 1992. Although more detailed evaluations are necessary, preliminary data suggest that opportunities for early intervention may be facilitated by the Service Coordination Program if the child's HIV status is recognized early.