The influence of paediatric HIV infection on circulating B cell subsets and CXCR5(+) T helper cells.

Antiretroviral therapy (ART) only partially restores HIV-induced alterations in lymphocyte populations. We assessed B and T cell phenotypes in a cohort of children from a single centre in the United Kingdom with perinatally acquired HIV compared to healthy controls. The majority of HIV infected children (44 of 56) were on fully suppressive combination ART. Children with perinatally acquired HIV had significantly lower memory B and CD4(+) CD45RO(+) CXCR5(+) [follicular T helper cell (Tfh)-like] T cell percentages. Detectable viraemia was associated with higher CD21(-) (activated and exhausted/tissue-like memory) B cells. A greater proportion of life spent on suppressive ART was associated with higher memory B cell percentages. These results suggest that early and sustained suppressive ART may preserve B and T cell phenotypes in perinatally acquired HIV and limit deficits in humoral immunity. A lower proportion of circulating Tfh-like cells in HIV infected children appears to be independent of HIV treatment history and ongoing HIV viraemia and warrants further investigation.

Tuberculosis in native Israeli Arabs and Jews: trends and treatment outcomes, 1999-2011.

The incidence of tuberculosis (TB) in native ethnic minorities remains high in developed countries. Arabs, the major ethnic minority in Israel, comprise 21% of its population. This retrospective study compared TB incidence, demographic, clinical, laboratory, genotyping characteristics and treatment outcomes in all Israeli-born citizens diagnosed with TB between 1999 and 2011 by ethnicity, i.e. Israeli-born Arabs (IA) and Jews (IJ). A total of 831 Israeli-born TB patients were reported. Of those, there were 530 (64%) IJ and 301 (36%) IA, with an average annual TB rate of 1·1 and 1·6 cases/100 000 population, respectively, lower than the national average (7·0 cases/100 000 population). TB rates in IA and IJ declined and converged to 1 case/100 000 residents. IA TB patients were more likely to be older, have more pulmonary TB and have lower treatment success rates than IJ. Older age and HIV co-infection, but not ethnicity, were predictive of non-success in TB treatment. Ten mixed IA-IJ clades were detected by spoligotyping and three mixed IA-IJ clusters were identified by MIRU-VNTR typing. Only one IA-IJ couple recalled mutual contact. In conclusion, TB rate in IA was higher than in IJ, but declined and converged in both to 1 case/100 000. Treatment success was high in both groups, and was unrelated to ethnicity.

Clinical manifestations of disease in X-linked carriers of chronic granulomatous disease.

Chronic Granulomatous Disease (CGD) is a rare primary immunodeficiency due to a defect in one of the NADPH oxidase complex subunits; 70 % of cases are X-linked, due to a CYBB mutation, resulting in defective production of gp91PHOX. Female carriers of X-linked CGD have previously been considered to be unaffected. It is increasingly recognized that they may suffer from similar problems to CGD patients. This review will examine the literature about clinical manifestations of disease in X-linked carriers of CGD.

Pneumococcal conjugate vaccine dose-ranging studies in humans: A systematic review.

BACKGROUND: Streptococcus pneumoniae is one of the most common bacterial pathogens of infants and young children. Antibody responses against the pneumococcal polysaccharide capsule are the basis of vaccine-mediated protection. We examined the relationship between the dose of polysaccharide in pneumococcal conjugate vaccines (PCVs) and immunogenicity. METHODS: A systematic search of English publications that evaluated the immunogenicity of varying doses of pneumococcal conjugate vaccines was performed in Medline and Embase (Ovid Sp) databases in August 2019. We included only articles that involved administration of pneumococcal conjugate vaccine in humans and assessed the immunogenicity of more than one serotype-specific saccharide dose. Results were synthesised descriptively due to the heterogeneity of product valency, product content and vaccine schedule. RESULTS: We identified 1691 articles after de-duplication; 9 studies met our inclusion criteria; 2 in adults, 6 in children and 1 in both. Doses of polysaccharide evaluated ranged from 0.44 mcg to 17.6 mcg. In infants, all doses tested elicited IgG geometric mean concentrations (GMCs) above the established correlate of protection (COP; 0.35 mcg/ml). A month after completion of the administered vaccine schedule, 95% confidence intervals of only three out of all the doses evaluated had GMCs that crossed below the COP. In the adult studies, all adults achieved GMCs that would be considered protective in children who have received 3 standard vaccine doses. CONCLUSION: For some products, the mean antibody concentrations induced against some pneumococcal serotypes increased with increasing doses of the polysaccharide conjugate, but for other serotypes, there were no clear dose-response relationships or the dose response curves were negative. Fractional doses of polysaccharide which contain less than is included in currently distributed formulations may be useful in the development of higher valency vaccines, or dose-sparing delivery for paediatric use.

Cross-sectional prevalence of SARS-CoV-2 antibodies in healthcare workers in paediatric facilities in eight countries.

BACKGROUND: Healthcare workers (HCWs) have been disproportionately affected by coronavirus disease 2019 (COVID-19), which may be driven, in part, by nosocomial exposure. If HCW exposure is predominantly nosocomial, HCWs in paediatric facilities, where few patients are admitted with COVID-19, may lack antibodies to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and be at increased risk during the current resurgence. AIM: To compare the seroprevalence of SARS-CoV-2 amongst HCWs in paediatric facilities in seven European countries and South Africa (N=8). METHODS: All categories of paediatric HCWs were invited to participate in the study, irrespective of previous symptoms. A single blood sample was taken and data about previous symptoms were documented. Serum was shipped to a central laboratory in London where SARS-CoV-2 immunoglobulin G was measured. FINDINGS: In total, 4114 HCWs were recruited between 1st May and mid-July 2020. The range of seroprevalence was 0-16.93%. The highest seroprevalence was found in London (16.93%), followed by Cape Town, South Africa (10.36%). There were no positive HCWs in the Austrian, Estonian and Latvian cohorts; 2/300 [0.66%, 95% confidence interval (CI) 0.18-2.4] HCWs tested positive in Lithuania; 1/124 (0.81%, 95% CI 0.14-4.3) HCWs tested positive in Romania; and 1/76 (1.3%, 95% CI 0.23-7.0) HCWs tested positive in Greece. CONCLUSION: Overall seroprevalence amongst paediatric HCWs is similar to their national populations and linked to the national COVID-19 burden. Staff working in paediatric facilities in low-burden countries have very low seroprevalence rates and thus are likely to be susceptible to COVID-19. Their susceptibility to infection may affect their ability to provide care in the face of increasing cases of COVID-19, and this highlights the need for appropriate preventative strategies in paediatric healthcare settings.

Natural human antibodies to pneumococcus have distinctive molecular characteristics and protect against pneumococcal disease.

The molecular and functional characteristics of natural antibody from the preimmune repertoire have not been explored in detail in man. We describe seven human IgM monoclonal antibodies selected on the basis of pneumococcal polysaccharide binding that share both molecular and functional characteristics with natural antibody, suggesting a common B cell lineage origin. Unlike class-switched antibodies, which are serotype-specific, the antibodies were polyreactive and bound all pneumococcal polysaccharide capsular serotypes tested. Some bound endogenous antigens, including blood group antigens and intermediate filament proteins. All the antibodies used unmutated heavy chain V (IGHV) that are expressed at an increased frequency in the elderly and in the preimmune repertoire. The CDR3 was characterized by long length (mean aa 18.4 (+/-4.2) and selective use of IGHD6 (P < 0.001) and IGHJ6 (P < 0.01) family genes. The clones expressing IGHV1-69 and IGHV 3-21 provided significant passive protection against invasive pneumococcal disease in vivo.

Special article: chronic granulomatous disease in the United Kingdom and Ireland: a comprehensive national patient-based registry.

There are no epidemiological studies from the British Isles of chronic granulomatous disease, characterized by recurrent, life-threatening bacterial and fungal infections and inflammatory sequelae. Patients were enrolled in a national registry and medical records were analysed. Of 94 subjects, 69 had X-linked disease, 16 had autosomal recessive disease and nine were unknown. Prevalence was 7.5/million for 1990-99 and 8.5/million for 1980-89. Suppurative adenitis, abscesses and pneumonia presented commonly. Twenty-three of 30 patients who underwent high resolution computerized tomography had chronic respiratory disease. Inflammatory sequelae included bowel stricture and urogenital tract granulomata. Growth failure was common; 75% of those measured were below the population mean. All patients received prophylactic antibiotics and 93% anti-fungal prophylaxis. Interferon gamma was used to treat infection, but rarely as prophylaxis. Despite prophylaxis, estimated survival was 88% at 10 years but 55% at age 30 years. Morbidity remains significant, severe infectious complications common. Curative treatments including stem cell transplantation should be considered for patients with frequent or serious complications.

Interlaboratory Comparison of the Pneumococcal Multiplex Opsonophagocytic Assays and Their Level of Agreement for Determination of Antibody Function in Pediatric Sera.

Opsonophagocytic assays are used to measure functional antibodies important in protection against pneumococcal capsular antigens. There have been efforts to standardize these methods, as the assays are commonly used to measure vaccine immunogenicity. We report here the results from three international laboratories using their own methods, based on the recommended WHO standard method. We tested 30 pediatric sera, before and after administration of a 13-valent conjugate pneumococcal vaccine, against all 13 serotypes. The three laboratories demonstrated good agreement using their own standardized multiplex opsonophagocytosis assay protocols, particularly postimmunization for those serotypes in the vaccine. While serotype-specific IgG methods have already been internationally standardized and are currently used as a measure of vaccine immunogenicity, this report demonstrates that despite minor differences in methods and a minor variation in response to nonvaccine serotypes, the results from opsonophagocytic assays across the three laboratories may be compared with confidence.IMPORTANCE When measuring a functional antibody response to pneumococcal immunization, it is imperative that a specific, reproducible, accurate, and standardized assay with acceptable inter- and intra-assay variation be advocated internationally to allow for meaningful comparison of results between laboratories. We report here the results of a collaboration between 3 international laboratories testing 30 pediatric samples against the 13 serotypes in Prevenar13.

Decreased insulin sensitivity of forearm muscle in myotonic dystrophy.

Previous studies of patients with myotonic dystrophy have demonstrated hyperinsulinism after glucose loading. This hyperinsulinism has been attributed by some investigators to tissue insulin resistance. We have directly studied insulin sensitivity of forearm muscle in patients having such hyperinsulinism. The effect of an intrabrachial arterial insulin infusion (100 mu U/kg per min) on glucose uptake was determined in six cases of myotonic dystrophy, six normal subjects, and in seven disease control subjects with myotonia or wasting from other disorders. There was no significant difference in insulin tolerance comparing myotonic dystrophy patients to the normal and disease control groups. Glucose tolerance and basal insulin levels were normal in the myotonic dystrophy patients, but hyperinsulinism occurred after glucose ingestion. After 25 min of intra-arterial insulin, the mean peak muscle glucose uptake in myotonic dystrophy was 2.54 +/- 0.54 mu mol/min per 100 ml forearm compared to 5.24 +/- 0.86 mu mol/min per 100 ml for disease controls (P is less than 0.05). Myotonic dystrophy patients showed a peak glucose uptake increment of only 2.6 +/- 0.2-fold over basal contrasted with the disease control value of 6.5 +/- 1.0-fold (P is less than 0.02) and the normal control value of 8.8 +/- 1.1-fold (P is less than 0.01). Thus, there was an absolute as well as a relative decrease in muscle insulin sensitivity in myotonic dystrophy patients compared to both control groups. The peak increments in arterio-superficial venous glucose concentration differences after insulin infusion were not significantly different comparing myotonic dystrophy and control groups. These data suggest that in myotonic dystrophy, there is insulin insensitivity of skeletal muscle.

Assignment of Weight-Based Antibody Units for Four Additional Serotypes to a Human Antipneumococcal Standard Reference Serum, 007sp.

The pneumococcal enzyme-linked immunosorbent assay (ELISA) reference standard serum, lot 89SF, had been in use since 1990 and was replaced with a new reference standard serum, 007sp, in 2013. This serum was generated under an FDA-approved clinical protocol where 278 adult volunteers were immunized with the 23-valent unconjugated polysaccharide vaccine Pneumovax II and a unit of blood was obtained twice within 120 days following immunization. Pooled serum was prepared from the plasma, filled at 6 ml per vial, and lyophilized. Five independent laboratories participated in bridging the serotype-specific IgG assignments of 89SF to 007sp to establish equivalent reference values for 13 pneumococcal capsular serotypes (1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, 23F) using the WHO reference ELISA. A subsequent follow-up study established equivalent reference values for an additional seven serotypes (8, 10A, 11A, 12F, 15B, 22F, 33F). In this study, three laboratories assigned weight-based IgG concentrations in micrograms per milliliter of serum to 007sp for four additional serotypes: 2, 9N, 17F, and 20A. This study completes the assignment of serotypes for 89SF to 007sp. In addition, the IgG antibody assignments for a 12-member WHO quality control (QC) serum panel were extended to cover the four additional serotypes. Agreement was excellent, with a concordance correlation coefficient (rc ) of >0.996 when values from each laboratory were compared to the assigned values for the 12 WHO QC sera. The 007sp preparation has replaced 89SF as the pneumococcal reference standard. Sufficient quantities of 007sp are projected to be available for the next 25 years.

Assignment of Opsonic Values to Pneumococcal Reference Serum 007sp for Use in Opsonophagocytic Assays for 13 Serotypes.

Opsonophagocytic assays (OPAs) are routinely used for assessing the immunogenicity of pneumococcal vaccines, with OPA data often being utilized for licensure of new vaccine formulations. However, no reference serum for pneumococcal OPAs is available, making evaluation of data among different laboratories difficult. This international collaboration was initiated to (i) assign consensus opsonic indexes (OIs) to FDA pneumococcal reference serum lot 007sp (here referred to as 007sp) and a panel of serum samples used for calibration of the OPA and (ii) determine if the normalization of the OPA results obtained with test samples to those obtained with 007sp decreases the variability in OPA results among laboratories. To meet these goals, six participating laboratories tested a panel of serum samples in five runs for 13 serotypes. For each serum sample, consensus OIs were obtained using a mixed-effects analysis of variance model. For the calibration serum samples, normalized consensus values were also determined on the basis of the results obtained with 007sp. For each serotype, the overall reduction in interlaboratory variability was calculated by comparing the coefficients of variation of the unadjusted and the normalized values. Normalization of the results substantially reduced the interlaboratory variability, ranging from a 15% reduction in variability for serotype 9V to a 64% reduction for serotype 7F. Normalization also increased the proportion of data within 2-fold of the consensus value from approximately 70% (average for all serotypes) to >90%. On the basis of the data obtained in this study, pneumococcal reference standard lot 007sp will likely be a useful reagent for the normalization of pneumococcal OPA results from different laboratories. The data also support the use of the 16 FDA serum samples used for calibration of the OPA as part of the initial evaluation of new assays or periodic assessment of established assays.

Isolation and partial characterization of plasma membranes bearing human fetal-associated antigens.

A rabbit antiserum to first-trimester human fetal tissue had greater reactivity in complement fixation and saturation binding assays with fetal tissues than with both a pool of normal adult lung, liver, and kidney and pools of the individual organs. This anti-fetal membrane reactivity was only partially inhibited by carcinoembryonic antigen. The serum still reacted strongly with human fetal and tumor cells after rendering it specific for plasma membrane components by adsorption to and elution from intact human fetal tissue culture cells. This plasma membrane-specific serum was then used to monitor the purification of the fetal membrane-associated antigens. The fetal antigens copurified with the putative plasma membrane enzymatic markers 5'-nucleotidase and Mg2+-adenosinetriphosphatase through differential and density gradient centrifugation. Insulin-binding activity only partially copurified with the antigenic activity. Little antigenic activity was found in nuclear and mitochondrial fractions. The isolation protocol gives fetal plasma membrane-associated antigens in approximately 50% yield with moderate purification. The sera and isolation procedures described should have general utility for the detection of human oncofetal antigens.

Antigenicity of histones in various chromatins.

Antisera specific to purified histone fractions are used to assess the antigenicity of the histones present in chromatin derived from various sources. The results indicate that the antigenicity of the histones present in chromatin is markedly diminished as compared to the antigenicity of the histones free in solution. The antigenicity of histones in chromatins derived from three different tissues of the rat is very similar. The antigenicity of the histones present in chromatin derived from calf thymus is higher than that of the histones present in rat thymus. It is concluded that the major reason for diminished antigenicity of histones in chromatin is that the histones are complexed in the nucleosome conformation and that the antigenic determinants residing in histones in various chromatins are exposed to similar degrees.

Risk of relapse after meningococcal C conjugate vaccine in nephrotic syndrome.

In November, 1999, all children under age 18 years in the UK were offered immunisation with the newly introduced meningococcal C conjugate vaccine (MCCV). In a cohort of 106 patients with nephrotic syndrome, there were 63 relapses during the 12 months before vaccination, and 96 during the equivalent period postvaccination (p=0.009). The relapse rate of nephrotic syndrome increased significantly after administration of MCCV. Whether to vaccinate such children needs to be carefully considered.

Streptococcus pneumoniae serotype 1 burden in the African meningitis belt: exploration of functionality in specific antibodies.

Streptococcus pneumoniae serotype 1 (Sp1) constitutes an important cause of seasonal endemic meningitis in all age groups in the African meningitis belt. Despite a higher meningitis incidence, the Burkinabé population has an Sp1-specific antibody seroprevalence similar to that reported in the United Kingdom (UK). We aimed to establish whether the opsonophagocytic activity (OPA) of pneumococcal IgG naturally present in Burkina Faso differs from that seen in individuals in the UK and to compare the OPAs generated by natural and vaccine-induced immunity. Samples collected from pneumococcal vaccine-naive Burkinabé and UK subjects were matched for age (1 to 39 years) and anti-Sp1 IgG level, analyzed for OPA to 3 S. pneumoniae serotypes (1, 5, and 19A), and compared to postvaccine samples. Furthermore, the Burkinabé samples were assessed for IgG avidity and serotype-specific IgM concentrations. One hundred sixty-nine matched serum samples from both populations were selected. A greater proportion of Burkinabé subjects aged 1 to 19 years had functional Sp1 activity (OPA ≥ 8) compared to UK subjects (12% versus 2%, P < 0.001); however, the proportions were similar among adults (9%). The correlation between Sp1 IgG concentration and OPA was good (P < 0.001), but many individuals had nonfunctional IgG, which was not related to avidity. While the Sp1 IgM concentrations correlated with OPA, not all of the function in serum samples with low IgG could be attributed to IgM. Finally, vaccine-induced Sp1-specific IgG was more functional than equivalent amounts of naturally occurring IgG. In conclusion, despite a substantially higher pneumococcal meningitis incidence, no decreased functional immunity to Sp1 could be evidenced in the Burkinabé population compared to that in the population from the UK. Furthermore, the naturally induced antibodies were less functional than vaccine-induced antibodies.

Assignment of Weight-Based Antibody Units for Seven Additional Serotypes to a Human Pneumococcal Standard Reference Serum, 007sp.

The pneumococcal enzyme-linked immunosorbent assay (ELISA) reference standard serum, lot 89SF, has been in use since 1990 and was replaced in 2013 with a new reference standard, 007sp, that is projected to be available for the next 25 years. 007sp was generated under an FDA-approved clinical protocol; 278 adult volunteers were immunized with the 23-valent unconjugated polysaccharide vaccine Pneumovax II, and a unit of blood was obtained twice from each immunized subject within 120 days following immunization. Pooled serum was prepared from the plasma of 262 subjects, filled at 6 ml per vial, and lyophilized. Five independent laboratories participated in bridging the serotype-specific IgG assignments for 89SF to the new reference standard, 007sp, to establish equivalent reference values for 13 pneumococcal capsular serotypes (1,3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, and 23F) by using the WHO reference ELISA. In a second study involving three laboratories, a similar protocol was used to assign weight-based IgG concentrations in micrograms per ml to 007sp of seven serotypes (8, 10A, 11A, 12F, 15B, 22F, and 33F) also present in the 23-valent pneumococcal unconjugated polysaccharide vaccine. In addition, the IgG assignments for a 12-member WHO quality control (QC) serum panel were also extended to cover these seven serotypes. Agreement was excellent, with a concordance correlation coefficient (r(c)) of >0.996 when each laboratory was compared to the assigned values for the 12 WHO QC serum samples. There are four remaining pneumococcal serotypes (2, 9N, 17F, and 20) found in Pneumovax II for which IgG assignments exist for 89SF and remain to be bridged.

Slow eye movements, with absent saccades, in a patient with hereditary ataxia.

Saccadic and smooth eye movements are controlled by separate mechanisms within the nervous system. We describe a patient with familial ataxia, considered to be a form of olivopontocerebellar degeneration, who is incapable of generating reflex or voluntary saccades. She can, however, move her eyes smoothly to the normal limits of lateral gaze, even when her head is prevented from moving. Latency before onset of movement is prolonged, and the velocity of movement is abnormally slow. We postulate that the degenerative process may have affected selectively those cells of the ventral paramedian pontine tegmentum responsible for the generation of saccades; and the the prolonged latency from presentation of a visual stimulus to the onset of movement is related to an inability to generate burst discharges needed to overcome the viscoelastic properties of the orbital tissues.

Managed care and the survival of neurology referral centers. A commitment to centers of excellence.

Since the collapse of federal health system reform legislation in 1994, there has been a growing concern with the quality of care provided within managed care systems. Just as physicians practicing under a traditional fee-for-service payment base have financial incentives to do as much as possible for each patient (doing well by doing good), physicians working for managed care plans are sometimes given perverse incentives to do as little as possible. A major quality-related concern among patients and payers (often referred to jointly and ambiguously as consumers of care) is the much larger role assigned to primary care physicians in managed care plans than is usually the case with traditional indemnity insurance.

Evaluation of pulmonary function in neuromuscular disease.

Pulmonary function tests were performed on 40 patients with neuromuscular disease. The maximum expiratory pressure was the most sensitive indicator of weakness and was decreased in 87% of adult patients. A comparison of Stead-Wells, electronic (Vanguard), and bellows spirometry (Vitalor) indicated an excellent correlation between the Stead-Wells and electronic devices. The bellows spirometer consistently underestimated volumes, particularly in severely weak patients.