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Measuring and interpretation of the immune response to pneumococcal polysaccharides is a complex field, owing to the diversity of the pneumococcal polysaccharide capsular types, different vaccine formulations including both polysaccharide and conjugate vaccines, diverse pneumococcal serological assays, lack of immunogenicity data for the conjugate in a number of at-risk groups and complex vaccine schedules. Even the reasons for performing pneumococcal serology can be complex, as assays may be performed for one of two reasons: either to assess an individual's immune status to the pneumococcus or to discriminate between normal and abnormal humoral immunity. This review details a history of the pneumococcal serological assays and provides some insight into when serology can prove useful, including vaccination data for certain at-risk groups.

Background: Patients with severe combined immunodeficiency and preexisting viral pneumonitis formally had a poor outcome from hematopoietic stem cell transplantation. With inhaled steroid and antitumor necrosis factor alpha antibody treatment, results improved. The poor outcome of patients with viral central nervous system infection prompted this retrospective single center review., Results: Eight of 71 patients with severe combined immunodeficiency transplanted since 1987 were identified with viral central nervous system infection (adenovirus [1], cytomegalovirus [2], Epstein-Barr virus [2], parvovirus [1], varicella zoster virus [1], human herpesvirus 6 [1]). Nonspecific neurologic symptoms included drowsiness, irritability, head lag, fisting and floppiness. Later symptoms included unresponsiveness, apnea, posturing, hypotonia, hyperreflexia and seizures. All had neuroradiologic investigations. Only one had an initially normal computed tomography scan. Magnetic resonance image abnormalities included cerebral atrophy, basal ganglia changes, diffuse leukoencephalopathy, and multifocal mass lesions. Five patients had virus identified from cerebrospinal fluid by polymerase chain reaction and brain tissue examination from 3 patients identified human herpesvirus 6, adenovirus type 41 and varicella zoster virus. Three children remain alive, 2 received replete marrow and one remains untransplanted. Others who received T cell depleted marrow died of neurologic sequelae., Conclusion: Outcome of viral central nervous system infection after hematopoietic stem cell transplantation for severe combined immunodeficiency is poor, particularly associated with T cell depleted marrow.

Wiskott-Aldrich syndrome, an X-linked primary immunodeficiency can be cured by bone marrow transplantation. Umbilical cord haemopoietic stem cells are increasingly used as an alternative to bone marrow; advantages include ready availability, no risk to the donor, low rate of viral contamination, and low risk of graft versus host disease. Disadvantages include low stem cell dose for larger patients and lack of stem cells for boost infusions following the initial procedure. We report the case of a child with Wiskott-Aldrich syndrome who underwent cord blood stem cell transplantation with two separate cord blood units, 8 days apart.

The aim of this study was to determine if gastroenteric viruses were present on surfaces and equipment in a pediatric primary immunodeficiency unit (PPIU) by environmental sampling using swabs and subsequent nucleic acid extraction and reverse transcriptase PCR assays. A PPIU was chosen, and 11 swabs were taken at the same sites every 2 weeks for 6 months. Nested/heminested PCR assays were used to screen for astroviruses (AsV), noroviruses (NoV), and rotaviruses (RV). AsV, NoV, and RV were detected at multiple swab sites during the study period. NoV was the most frequently detected virus on environmental surfaces; however, RV was detected on 79% and NoV on 50% of swabbing dates during the study period. Toilet taps were the most contaminated sites. Fecal samples from selected patients in the unit were also screened during the study period, and patients excreted AsV, NoV, and RV at times during the study. New cleaning schedules and changes in some of the PPIU sanitary furniture have been suggested as a means of reducing environmental contamination.

Primary immunodeficiencies (PID) are an important cause of childhood mortality. Haematopoietic stem cell transplantation (HSCT) is the best treatment for many PID. Umbilical cord stem cells are an alternative source of HSC. There is little data regarding outcome of umbilical cord stem cell transplantation (UCSCT) for PID. Our single centre experience is reported. A retrospective study of 14 of 148 patients transplanted for PID, who have received 15 UCSCT was performed, with specific regard to graft-versus-host disease (GvHD) and immune reconstitution. Eight patients with severe combined immunodeficiency (SCID), and six with other combined immunodeficiencies were treated. Of the patients, 12 received unrelated cords, and two had sibling transplants. Median age at transplant was 3.5 months, median nucleated cell dose was 0.8 x 10(8)/kg. All engrafted. Median time to neutrophil engraftment was 22 days, median time to platelet engraftment was 51 days. One developed significant grade III GvHD post transplantation. In total, 11 patients had full donor T and six full donor B-cell chimerism, six of nine patients >1 year post-BMT had normal IgG levels and specific antibody responses to tetanus and Hib vaccines; two are being assessed. Two patients died of multi-organ failure related to pre-existing infection and inflammatory complications respectively. UCSCT should be considered for patients requiring stem cell therapy for PID., (Bone Marrow Transplantation (2005) 36, 295-299.)

An outbreak of astrovirus gastroenteritis occurred in the Primary Immunodeficiency Unit at Newcastle General Hospital in March 2004. Environmental swabbing of the unit was undertaken after the outbreak, with multiple sites swabbed pre- and postcleaning. Astroviruses were detected in four environmental swabs and from two patient fecal samples using heminested reverse transcriptase PCR. An astrovirus genotype 3 strain was identified in both environmental swabs and fecal specimens and was the strain identified as being responsible for the outbreak. Environmental transmission of the virus was thought to have occurred by contamination of a syringe pump outside the laminar-flow curtain of a patient who was admitted with astrovirus gastroenteritis. This was subsequently transmitted to a cubicle next door and to a television/games console in a parents' room in the ward. Environmental monitoring of surfaces/equipment, using PCR assays for gastroenteric viruses in hospital situations where infection can give rise to serious clinical complications, may have a role in controlling and monitoring cleaning and the subsequent prevention of nosocomial transmission of gastroenteritis.

Aim: Medical and lay concerns about food allergy are increasing. Whilst food allergy may be becoming more common, fatal reactions to food in childhood are very rare and their rate is not changing. We sought to establish how common severe reactions are., Methods: Prospective survey, 1998 to 2000, of hospital admissions for food-allergic reactions-conducted primarily through the British Paediatric Surveillance Unit, covering the 13 million children in the United Kingdom and Ireland., Results: 229 cases reported by 176 physicians in 133 departments, yielding a rate of 0.89 hospital admissions per 100,000 children per year. Sixty-five per cent were male, 41% were under 4 y and 60% started at home. Main allergens were peanut (21%), tree nuts (16%), cow's milk (10%) and egg (7%). Main symptoms were facial swelling (76%), urticaria (69%), respiratory (66%), shock (13%), gastrointestinal (4%). Fifty-eight cases were severe. Three were fatal, six near fatal, and 8 of these 9 had asthma with wheeze being the life-threatening symptom. Three near-fatal cases received excess intravenous epinephrine. None of the non-fatal reactions resulted in mental or physical impairment. Seven of 171 non-severe and 6/58 severe cases might have had a worse outcome if epinephrine auto-injectors had been unavailable. Six of the severe cases might have benefited if auto-injectors had been more widely prescribed., Conclusion: In the United Kingdom and Ireland, the incidence of severe reactions is low. The study highlights that: asthma is a strongly significant risk factor for a severe reaction and therefore warrants optimal management; severe wheeze is a prominent feature of severe reactions and warrants optimal management; intravenous epinephrine should be used with great care if needed. Epinephrine auto-injectors do not always prevent death, but our study design and data do not allow a definite statement about whether overall they are beneficial.

This observational study describes the ranges observed for lymphocyte subsets for significantly preterm infants (<32 weeks) in the first year of life, measured by single platform flow cytometry and compared to identically determined subsets in term infants. After ethical approval 39 term and 28 preterm infants had lymphocyte subset analysis before and after their primary immunization series. Median values with 5th and 95th percentiles of absolute counts and percentages are presented for total lymphocytes, T cells, NK cells, B cells, cytotoxic T cells, helper T cells, dual positive T cells, activated T cells, activated T helper cells (including T regulatory cells), pan memory T cells, pan naive T cells, memory helper T cells, naive helper T cells and the T helper/suppressor ratio. The lymphocyte profile of the preterm infants differed from that of the term infants.

Haemopoietic stem cell transplants (HSCT) cure increasing numbers of primary immunodeficiencies (PID): residual recipient T-cell function increases risk of incomplete or decreasing immune reconstitution, which may resolve following a second, unconditioned, infusion from the same donor (boost infusion). We assessed the outcome of 20 boost infusions in 19/139 patients transplanted for PID patients at our centre since 1987. Boost infusion was given 64-1226 days after the original HSCT. Follow-up was 4-124 months. In all, 12 of 19 patients cleared viral infection (6), or showed sustained increase in donor chimerism, T- and B-cell numbers and function, or other markers (6). In 7/12 patients, immunoglobulin replacement has been discontinued. Four were partially successful with stable low-level chimerism (two patients) or improved T-cell function, but not B cell function (two patients). Four failed with no change in donor chimerism or cell number. No significant association with donor source, T-cell depletion, conditioning regimen, boost infusion stem cell dose or time from original HSCT to boost was found. One patient developed grade III acute graft-versus-host disease despite cyclosporine, and one developed severe pneumonitis; both have recovered. Boost infusion was successful or partially successful in 84% of patients. The risk of adverse effects is low.

Adenovirus causes disseminated disease following bone marrow transplantation (BMT). We report a child who underwent T-cell-depleted BMT. Adenovirus subgenus F serotype 41 was detected antemortem by PCR in cerebrospinal fluid and postmortem in other tissues. Serotypes 40 and 41, associated with gastrointestinal disease, have not previously been implicated in disseminated disease.

Fanconi anemia (FA), an autosomal recessive chromosomal instability syndrome, is characterized clinically by developmental abnormalities, growth retardation, progressive bone marrow failure, pancytopenia, and pronounced cancer predisposition. Nijmegen Breakage Syndrome (NBS) is a related disorder that shares overlapping clinical features, principally, developmental delay, microcephaly, and cancer predisposition. The diagnosis has relied on chromosomal instability following exposure to DNA cross-linking agents in FA and to ionizing radiation (IR) in NBS. We describe two patients who clinically had FA, but showed sensitivity to both DNA cross-linking agents and ionizing radiation, and who were found to have a rare mutation in the NBS gene. The importance of genetic diagnosis with respect to treatment and prognosis is discussed.

Thyroid dysfunction, a common long-term complication following bone marrow transplantation (BMT), is frequently associated with total body irradiation (TBI) given in the pre-BMT conditioning protocol. We report our preliminary observation of the prevalence of thyroid dysfunction in children transplanted for primary immunodeficiency (PID) who were given cytoreductive conditioning with busulphan and cyclophosphamide, but without TBI. We evaluated thyroid-stimulating hormone (TSH) and free thyroxine (fT4) in 83 survivors transplanted between 1987 and 2002. We found nine children (10.8%) with clinical and/or biochemical thyroid dysfunction at 4 months to 4.5 years post-BMT of which three had positive antithyroid microsomal antibodies. Two patients were classified as primary and seven as compensated hypothyroidism (hyperthyrotropinaemia). Four patients with clinical features of hypothyroidism received replacement thyroxine, while five of the seven patients with compensated hypothyroidism remain off thyroxine because we suspect this may be a transient phenomenon. Abnormalities of thyroid function including severe primary hypothyroidism may occur post-BMT in children receiving chemotherapy conditioning without TBI. Thyroid function should be assessed regularly in this group of patients.

A child is described who had the signs of autoimmune lymphoproliferative syndrome from an early age and later developed a blistering dermatosis that was shown to be childhood linear IgA disease.

CD40 ligand (CD40L) deficiency causes recurrent sinopulmonary infection, Pneumocystis carinii pneumonia, and Cryptosporidium parvum infection. Approximately 40% to 50% of patients survive to the third decade: long-term survival is unclear. Hematopoietic stem cell transplantation (HSCT) is curative. We present a retrospective analysis of 38 European patients undergoing HSCT for CD40L deficiency in 8 European countries between 1993 and 2002. Donor stem cell source included 14 HLA-identical siblings, 22 unrelated donors, and 2 phenotypically matched parental stem cells (12 T-cell depleted). Of the patients, 34 engrafted and 26 (68%) survived; 3 had autologous reconstitution, 22 (58%) were cured, and 1 engrafted but has poor T-cell immune reconstitution. There were 18 evaluated patients who responded to vaccination. Of the patients, 12 (32%) died from infection-related complications, with severe cryptosporidiosis in 6. Grades 2 to 4 graft-versus-host disease (GvHD) associated with infection occurred in 6 of 12 fatal cases. HSCT cured 58% of patients, 72% of those without hepatic disease. Early T-cell function following whole marrow HSCT may limit cryptosporidial disease, but survival was similar after T-cell-depleted HSCT. Preexisting lung damage was the most important adverse risk factor. Further studies will determine optimal timing and type of HSCT.

Patients with chronic mucocutaneous candidiasis (CMC) are selectively unable to clear the yeast Candida, which results in persistent debilitating infections affecting the skin, nails, and mucous membranes. The underlying defect is unknown. Recent animal studies highlighted the importance of type 1 cytokines in protection against Candida, and previous work suggested that CMC patients may exhibit altered cytokine production in response to Candida. Based on these findings, in this study we investigated cytokine production in CMC patients by assessing a range of inflammatory, anti-inflammatory, type 1, and type 2 cytokines (interleukin-2 [IL-2], IL-4, IL-5, IL-6, IL-10, IL-12, gamma interferon [IFN-gamma], tumor necrosis factor alpha [TNF-alpha]) in whole-blood cultures in response to five different fractions of Candida albicans (carbohydrate, purified mannan, and protein-rich fractions, etc.), as well as non-Candida antigens. Our results demonstrate that cytokine production is deregulated in a Candida-specific way for some cytokines (IL-2, IL-10), is deregulated more generally for other cytokines (IL-12, IL-6, IFN-gamma), and is not markedly altered for still other cytokines (TNF-alpha, IL-4, IL-5). The most notable finding in CMC patients was the markedly impaired production of IL-12 in parallel with dramatically increased levels of IL-6 and IL-10 that occurred selectively in response to Candida. These results suggest that patients with CMC have impaired production of type 1-inducing cytokines (possibly a macrophage or dendritic cell defect?), which could result in an inability to mount protective cell-mediated responses and a failure to clear Candida. Continued tissue damage and inflammation may trigger production of high levels of inhibitory cytokines, such as the IL-10 production seen in our study, which would further reduce production of type 1-inducing cytokines in a positive feedback loop leading to persistent infection.

Established treatment of severe combined immunodeficiencies (SCID) and other primary immunodeficiencies (PID) is bone marrow transplantation (BMT). Normal lymphocyte numbers and protein antigen responses are present within 2 years of BMT, polysaccharide antibody responses appear last. Streptococcus pneumoniae infection causes significant morbidity and mortality post-BMT. Previous studies have shown good protein antigen responses post-BMT for SCID and PID, but had not examined the polysaccharide responses. We retrospectively analysed pneumococcal polysaccharide (PPS) responses in our patient series. In total, 22 SCID and 12 non-SCID PID were evaluated, all >2 years post BMT: 17 SCID, 12 PID received chemotherapy conditioning; 17 SCID, three PID had T-cell depleted (TCD) BMT, others had nonconditioned whole marrow BMT. All had normal Haemophilus influenza B and tetanus antibody responses. Of 22 SCID, 13 vs 11/12 PID responded to PPS vaccine (P=0.05). There was no association with donor age, GvHD, B-cell chimerism, or IgG2 level. Fewer TCD marrow recipients responded to PPS (P=0.04). Analysis of the SCID group showed no association of PPS response with type of marrow received. This is the first study to specifically examine PPS antibody responses following SCID and PID BMT. Pneumococcal conjugate vaccine antibody responses should be examined in these children.

Hepatic veno-occlusive disease (HVOD) following bone marrow transplantation is potentially fatal. Criteria for diagnosis and starting treatment are mainly based on adult studies. Recombinant tissue plasminogen activator (rtPA) has been used with variable success. rtPA and heparin were given to 12 children (nine with immunodeficiency, two malignancy, one thalassaemia) with moderate to severe HVOD. Of the 12, 10 responded with a fall in bilirubin concentration; eight survived with complete resolution of HVOD. Four of the five patients with associated multiorgan failure (MOF) died despite rtPA treatment. One child suffered significant, and one minor, bleeding during rtPA treatment. A scoring system for quantifying the severity of HVOD in children is proposed, incorporating the criteria used to diagnose HVOD, risk factors for its development and also parameters reflective of the patient's general condition. This will facilitate early diagnosis and management of those cases which, if not treated promptly, are likely to deteriorate with an adverse outcome. Our experience suggests rtPA and heparin are an effective treatment for HVOD in children, with relatively little toxicity provided therapy is started before MOF develops.

Chronic granulomatous disease (CGD) causes growth failure, inflammatory lung damage and often early death. Prophylactic cotrimoxazole improves medium-term survival, but cannot prevent inflammatory sequelae. We report the first patient with CGD who underwent successful HLA identical sibling umbilical cord stem cell transplantation (UCSCT) after myeloablative conditioning. The patient presented with colitis, confirmed as CGD at 2 years of age. Following BU16/CY200 conditioning, he had UCSCT from his unaffected HLA identical sister. A year post-transplant, his colitis had resolved clinically and on radioisotope scan growth has improved. Neutrophil oxidative burst was 92% normal with full donor lymphocyte reconstitution.

Hereditary periodic fever syndromes comprise a group of distinct disease entities linked by the defining feature of recurrent febrile episodes. Hyper IgD with periodic fever syndrome (HIDS) is caused by mutations in the mevalonate kinase (MVK) gene. The mechanisms by which defects in the MVK gene cause febrile episodes are unclear and there is no uniformly effective treatment. Mutations of the TNFRSF1A gene may also cause periodic fever syndrome (TRAPS). Treatment with the TNFR-Fc fusion protein, etanercept, is effective in some patients with TRAPS, but its clinical usefulness in HIDS has not been reported. We describe a 3-year-old boy in whom genetic screening revealed a rare combination of two MVK mutations producing clinical HIDS as well as a TNFRSF1A P46L variant present in about 1% of the population. In vitro functional assays demonstrated reduced receptor shedding in proband's monocytes. The proband therefore appears to have a novel clinical entity combining Hyper IgD syndrome with defective TNFRSF1A homeostasis, which is partially responsive to etanercept.

Background: Although severe T cell immunodeficiency in DiGeorge anomaly is rare, previous studies of humoral function in these patients have found no antibody abnormalities but have not examined the response to polysaccharide antigens. Isolated cases of autoimmunity have been reported. Several patients with 22q11.2 deletion attending our immunology clinic suffered recurrent sinopulmonary infection or autoimmune phenomena., Aims: To investigate humoral immunodeficiency, particularly pneumococcal polysaccharide antibody deficiency, and autoimmune phenomena in a cohort of patients with 22q11.2 deletion., Methods: A history of severe or recurrent infection and autoimmune symptoms were noted. Lymphocyte subsets, immunoglobulins, IgG subclasses, specific vaccine antibodies, and autoantibodies were measured. Subjects were vaccinated with appropriate antigens as indicated., Results: Of 32 patients identified, 26 (81%) had severe or recurrent infection, of which 13 (50%) had abnormal serum immunoglobulin measurements and 11/20 >/=4 years old (55%) had an abnormal response to pneumococcal polysaccharide. Ten of 30 patients (33%) had autoimmune phenomena; six (20%) were symptomatic., Conclusions: Humoral immunodeficiency is more common than previously recognised in patients with 22q11.2 deletion. Normal T cell function and immunoglobulin levels do not exclude poor specific antibody responses. Patients should be referred for formal immunological assessment of cellular and humoral immune function.

Human primary immunodeficiency diseases are experiments of nature characterized by an increased susceptibility to infection. In many cases, they are also associated with troublesome and sometimes life-threatening autoimmune complications. In the past few years, great strides have been made in understanding the molecular basis of primary immunodeficiencies, and this had led to more focused and successful treatment. This review has 3 aims: (1) to highlight the variety of autoimmune phenomena associated with human primary immunodeficiency diseases; (2) to explore how primary immunodeficiencies predispose patients to autoimmune phenomena triggered by opportunistic infections; and (3) to consider the rationale for the current treatment strategies for autoimmune phenomena, specifically in relation to primary immunodeficiency diseases. Reviewing recent advances in our understanding of the small subgroup of patients with defined causes for their autoimmunity may lead to the development of more effective treatment strategies for idiopathic human autoimmune diseases.

Aims: To discover the incidence of fatal and severe allergic reactions to food in a large population of children., Methods: A retrospective search for fatalities in children 0-15 years from 1990 to February 1998, primarily of death certification at offices of national statistics. A prospective survey of fatal and severe reactions from March 1998 to February 2000, primarily through the British Paediatric Surveillance Unit., Main Outcome Measures: were deaths and severe reactions. A case was deemed severe if one or more of the following criteria was met: cardiorespiratory arrest; need for inotropic support; fluid bolus >20 ml/kg; more than one dose of epinephrine; more than one dose of nebulised bronchodilator. A case was deemed near fatal if intubation was necessary., Results: The UK under 16 population is 13 million. Over the past 10 years, eight children died (incidence of 0.006 deaths per 100 000 children 0-15 years per year). Milk caused four of the deaths. No child under 13 died from peanut allergy. Two children died despite receiving early epinephrine before admission to hospital; one child with a mild food allergic reaction died from epinephrine overdose. Over the past two years, there were six near fatal reactions (none caused by peanut) and 49 severe ones (10 caused by peanut), yielding incidences of 0.02 and 0.19 per 100 000 children 0-15 years per year respectively. Coexisting asthma is more strongly associated with a severe reaction than the severity of previous reactions., Conclusions: If 5% of the child population have food allergy, the risk that a food allergic child will die from a food allergic reaction is about 1 in 800 000 per year. The food allergic child with asthma may be at higher risk. Prescribing an epinephrine autoinjector requires a careful balance of advantages and disadvantages.

Background and Aims: The incidence of complement abnormalities in the UK is not known. It is suggested in at least three major paediatric textbooks to test for abnormalities of the complement system following meningococcal disease (MCD)., Methods: Over a four year period, surviving children with a diagnosis of MCD had complement activity assessed. A total of 297 children, aged 2 months to 16 years were screened., Results: All children except one had disease caused by B or C serogroups. One child, with group B meningococcal septicaemia (complicated by disseminated intravascular coagulation and who required ventilation and inotropic support) was complement deficient. C2 deficiency was subsequently diagnosed. She had other major pointers towards an immunological abnormality prior to her MCD., Conclusion: It is unnecessary to screen all children routinely following MCD if caused by group B or C infection. However, it is important to assess the previous health of the child and to investigate appropriately if there have been previous suspicious infections, abnormal course of infective illnesses, or if this is a repeated episode of neisserial infection.

Four transacting genes, CIITA, RFXANK, RFX5, and RFXAP, control coordinate MHC II expression. In humans, defects in these genes result in the absence of MHC II expression and thus a combined immunodeficiency. CIITA is considered to be a master MHC II regulator and is responsible for the defect in complementation group A. Eight such affected families have been reported. We investigated the molecular basis of the defect in three patients in these families, all presenting a severe immunodeficiency. CIITA transcripts were detected in all three patients but in one at an abnormally low level. Three novel heterozygous mutations of CIITA were found in patients SP and RC. One SP CIITA allele contained a nonsense mutation, G2178A, leading to a premature stop codon and the other allele in SP was found not to be expressed. In patient RC, two in-frame deletions were detected: one of the nucleotides 3003-3084 corresponding to the exon coding from Leu(964)to Asp(991), in the paternal allele, and a CATdel3193-5 of the isoleucine codon at position 1027, in the maternal allele. Transfection of a CIITA-deficient cell line with the recombinant CATdel3193-5-CIITA cDNA revealed a loss of function for this mutant and retention of the protein in the cytoplasm. No mutations were detected in the 4.5-kb cDNA from patient OK but the level of CIITA transcript was found to be profoundly decreased. However, promoters III and IV were not affected. This last case represents the first described CIITA dysfunction due to putative mutation(s) in cis regulatory sequences of CIITA.

Objectives: Fever is a common symptom in children presenting to casualty. Identifying the seriously ill is difficult. Previous studies, mainly from North America, suggest that symptoms, signs and simple investigations may help to do this. The aim of the present study was to assess the causes of fever and identify clinical and laboratory features suggesting serious disease in U.K. children presenting to hospital with temperatures >or=38 degrees C., Methods: All children with a temperature of >or=38 degrees C seen in two hospitals between August and October 1999., Results: One hundred and forty one children between 8 days and 16 years of age were studied, 64% male, 55% aged under 2 years. Eighty three percent had temperatures between 38 and 39 degrees C. Ninety six percent were casualty or GP referrals and 4% were tertiary referrals. Twenty nine percent (41/141) had serious disease but microbiologically or radiologically proven in only 22% (31/141); pneumonia (nine), meningitis (seven), sepsis (five), urinary tract infection (five), brain abscess (two), toxic shock syndrome (one), appendicitis (one), ischiorectal abscess (one). Forty two percent (5/12) of microbiologically proven meningitis and sepsis and 36% (8/22) of all meningitis and sepsis were meningococcal. Seventy one percent had non-serious diseases. In cases of serious disease the temperature was >39 degrees C in 15% (sensitivity: 14%, specificity: 82%, PPV: 25%). Poor feeding and restlessness predicted serious disease with a sensitivity of 78% and 76%, respectively. Full blood count (FBC) was taken in 50% of patients on admission; in 44% of serious and 24% of non-serious diseases WBC was between 5000 and 15,000/mm(3) and WBC >or=15,000/mm(3) was seen in 39% of serious diseases (sensitivity:10%, specificity: 95%, PPV: 44%)., Conclusions: One out of three of children referred with fever had a serious disease. Degree of temperature and WBC count were poor predictors of serious disease. Interestingly, poor feeding and restlessness were more sensitive predictors, suggesting high fever and WBC count can not replace clinical assessment of the child with a temperature., (Copyright 2001 The British Infection Society.)

Background: CD40 ligand (CD40L) deficiency is a rare X linked immunodeficiency disorder leading to recurrent bacterial infection, with cryptosporidial enteritis and subsequent hepatic cirrhosis. Bone marrow transplantation offers the only cure., Objective: To analyse retrospectively the outcome of bone marrow transplantation for this condition in one centre., Design: A retrospective case note analysis was performed, identifying all patients with CD40L deficiency who had undergone bone marrow transplantation between May 1988 and December 2000. Details of pre-existing infection, pretransplantation immunological and infective data, transplant procedure (particularly donor type and HLA match), conditioning regimen, and marrow manipulation were analysed. Post-transplantation data including infective episodes, engraftment details, immune function, complications, and outcome were recorded., Results: Eight boys (age 1-14 years, median 5.75) had transplants. Six received T cell depleted unrelated donor marrow. Four survive and have normal immune function. Six had previous Pneumocystis carinii pneumonia and three had histological liver damage. Survival was associated with younger age at transplantation and normal liver histology., Conclusions: Bone marrow transplantation can be curative in CD40L deficiency. Better outcome is associated with younger age at transplantation and normal liver histology.

Tuberculosis (TB) is a serious disease of global importance, with a rising incidence in the developed world in recent years. Tuberculous lymphadenitis, tuberculous meningitis, osteoarticular tuberculosis and miliary tuberculosis are some of the more well-recognised manifestations of non-pulmonary TB in childhood. The diagnosis of non-pulmonary TB poses a particular challenge for clinicians because of the protean ways in which the disease presents. The omission of tuberculosis from the differential diagnosis of patients with obscure illnesses and the relatively insensitive bacteriological methods for detecting Mycobacterium tuberculosis add to the complexity of the problem. A high index of suspicion is required in order to avoid delays in diagnosis which may influence treatment outcome. The advent of DNA amplification techniques such as the polymerase chain reaction may herald a promising new era in the prompt and accurate management of extrapulmonary tuberculosis.

Early diagnosis of severe combined immunodeficiency (SCID) is important to enable prompt referral to a supraregional centre for bone marrow transplantation before the occurrence of end organ damage secondary to infective complications. This review outlines clinical, microbiological, and immunopathological clues that aid the diagnosis of SCID and emphasises the multidisciplinary approach needed to diagnose and treat these infants.

Pneumococcal polysaccharide (PPS) antibody deficiency occurs in some children immunosuppressed following cardiac transplantation in early childhood. We studied lymphocyte subset populations in these children to identify patterns associated with antibody deficiency, particularly in CD21 + B cells. Lymphocyte surface markers CD3, CD4, CD8, CD19, and CD21 were measured on whole blood by FACS analysis in four patient groups: cardiac transplant patients who did and did not respond to PPS, nontransplanted cardiac patients, and normal controls. Absolute cell numbers were compared with age-related normal ranges. The proportion of children with values below the age-related 25th percentile in each group was compared. Normal controls had significantly more CD3+, CD8+, and CD19+ cells, even when age-related differences were accounted for. Control groups had significantly more CD19 cells than transplant patients and transplanted PPS responders and cardiac controls had more mature B cells (CD21+) than transplanted PPS nonresponders. PPS antibody deficiency following pediatric cardiac transplantation may be related to an immaturity in B cells due to immunosuppression commenced in early childhood.

We previously have demonstrated impaired pneumococcal polysaccharide IgG antibody responses in children immunosuppressed following cardiac transplantation in early childhood. We have further characterized the antibody defect. To further investigate the production of antibody, antipneumococcal polysaccharide (PPS) specific IgM, IgG, IgG subclasses, and IgA were measured in postvaccination sera by enzyme-linked immunosorbent assay. Two groups were studied: posttransplant children who made pneumococcal antibody in vivo following natural exposure or PPS immunization (R) and those with an impaired response (NR). There was no difference in IgM or IgA levels between R and NR. IgG and IgG2 levels were higher in R than NR (P = 0.002), even after adsorption of nonspecific common cell wall antigen antibody. Differences in anti-pneumococcal antibody levels suggest that immunoglobulin isotype switching from IgM to IgG and particularly IgG2 is impaired in patients immunosuppressed at a young age. These findings confirm data regarding the effect of immunosuppressive agents derived from animal models in humans.

Unlabelled: A preterm baby born with scaly skin who later developed recurrent infections and was subsequently diagnosed to have Omenn syndrome is presented., Conclusion: Any baby with ichthyotic skin and recurrent infections should have immunodeficiency considered in the differential diagnosis.

Fas-mediated apoptosis may be one of the effector pathways leading to the elimination of virus-infected cells. Cytomegalovirus (CMV) infection in two brothers with Fas deficiency associated with autoimmunity and benign lymphoproliferation (ALPS) provided a unique opportunity to study the clinical course of CMV infection in children with defective apoptosis. The clinical courses of two brothers with autosomal dominant ALPS who were infected with CMV in the neonatal period are described. CMV was detected from throat and urine culture from the brothers. ALPS was confirmed by in vitro anti-CD95 MoAb-induced T lymphocyte apoptosis assay and subsequent sequencing and identification of mutations in the Fas gene. A de novo mutation in the Fas gene, leading to a truncated cytoplasmic Fas product, was associated with autosomal dominant ALPS in a mother and her two sons. Both boys had evidence of CMV infection acquired early in infancy which cleared by the age of 2-3 years. There were no neurodevelopmental sequelae. The natural history of CMV infection in two infants with ALPS was similar to that described in normal children.

Presentation characteristics were reviewed in 14 children from 12 families with malignant infantile osteopetrosis seen at two large referral centres for bone marrow transplantation. Children from six of these families presented initially with symptoms of hypocalcaemia. These comprised early or late neonatal convulsions in six cases (corrected serum calcium < 1.5 mmol/l), and vomiting and irritability (serum calcium 1.68 mmol/l) in another. One other related child had severe and persistent jittering episodes almost certainly attributable to hypocalcaemia. In seven of eight cases, these symptoms developed during the first 14 days of life. Although occasionally reported previously, malignant infantile osteopetrosis remains essentially unrecognised as a cause of neonatal hypocalcaemia, often resulting in diagnostic confusion and delay. This is important in the context of curative haemopoietic stem cell transplantation where preservation of sight may depend on early intervention.

Background: Pneumocystis carinii is an important pathogen in immunodeficiency but may be an unrecognised cause of respiratory compromise., Objectives: To ascertain the incidence of P carinii pneumonia (PCP) at presentation of severe combined immunodeficiency (SCID), whether it had been diagnosed, and the effect of treatment on outcome., Setting: The supraregional paediatric bone marrow transplant unit for primary immunodeficiencies at Newcastle General Hospital., Methods: Retrospective case note review of infants referred with a diagnosis of SCID from 1992 to 1998., Results: Ten of 50 infants had PCP at presentation; only one was diagnosed before transfer. Eight were diagnosed by bronchoalveolar lavage and two by lung biopsy. In only one was P carinii identified in nasopharyngeal secretions. Five required ventilation for respiratory failure but all were successfully treated with co-trimoxazole and methylprednisolone with or without nebulised budesonide. Nine survived to bone marrow transplantation and four are long term survivors after bone marrow transplantation; no deaths were related to PCP., Conclusions: PCP is a common presenting feature of SCID but is rarely recognised. Bronchoalveolar lavage or lung biopsy are needed for diagnosis. Treatment with co-trimoxazole is highly successful.

Neurological complications of malignant infantile osteopetrosis are well recognised; successful bone marrow transplantation, when performed early in life, can prevent or halt some of them. In a subgroup of infants osteopetrosis is associated with primary retinal degeneration and/or generalised neurodegeneration. Bone marrow transplantation, in spite of being successful in correcting the osseous and haematological abnormalities, does not influence the progressive course of the neurodegenerative disorder. Thus, the recognition of this subgroup of infants with a very poor prognosis is essential before deciding on bone marrow transplantation.

Unlabelled: A wide spectrum of lung disease can complicate primary immunodeficiencies and early recognition influences management and prognosis. Computed tomography (CT) especially high resolution computed tomography (HRCT) has been shown to detect lung disease in adult immunodeficient patients often when the chest radiograph (CXR) is normal, but this has not been studied in children. Twenty-five CT scans [10 HRCT] and CXRs were reviewed in 23 children [14 male, 9 female] with primary immunodeficiency. Eighteen [72%] of the CT scans were abnormal, bronchiectasis being the commonest finding present in eight CT scans in patients with antibody deficiency. In eight cases CT scan revealed changes not seen on CXR (bronchiectasis; interstitial changes; small parenchymal nodules; air trapping;and a small upper lobe cyst) which influenced treatment in six cases., Conclusion: CT scans have a valuable role in assessing lung disease in children with primary immunodeficiencies and will detect important changes not visible on CXR.

Respiratory syncytial virus and parainfluenza virus infection carry a poor prognosis in severe combined immunodeficiency (SCID), particularly if the viral load is high. Patients with high viral load develop severe pneumonitis at engraftment which may possibly be modulated by immunotherapy, including high dose nebulised corticosteroids. Further work is required to develop effective treatment for this severe condition.

Background: Three children who had cardiac transplantation before age 4 years later presented with recurrent sinopulmonary infection caused by organisms including Streptococcus pneumoniae, in which capsular polysaccharide plays an important part, one developed bronchiectasis. We therefore studied responses to polysaccharide antigen after immunosuppression started in early childhood., Methods: Antibodies against pneumococcal and haemophilus polysaccharides, and total IgG, IgG1, IgG2, and IgA concentrations were measured in 33 cardiac-transplant recipients transplanted before the age 4 years (group 1) and after that age (group 2). Patients with low pneumococcal and haemophilus antibody concentrations were immunised with 23 polyvalent pneumococcal and tetanus-haemophilus conjugate vaccines and antibody responses were measured., Findings: Five patients from group 1 and seven from group 2 were transplanted for congenital heart disease and ten patients in each group had heart transplants because of cardiomyopathy; none were asplenic. Group 1 (16 patients) were aged 2-10 years when investigated, group 2 (17 patients), were 6-16 years. Four of 16 patients in group 1 responded to pneumococcal polysaccharide vaccine compared with 14 of 17 in group 2 (p=0.0016). This difference remained when those in group 1, aged less than 4 years at investigation, were excluded (p=0.0060). Response to haemophilus-conjugate vaccine was similar in both groups (14 of 16 vs 14 of 17, p=1.0). Significantly more patients who failed to respond to pneumococcal vaccine had low IgG2 concentrations (p=0.0269)., Interpretation: Children who had a transplantation and immunosuppression in early childhood before they had developed antibody responses to pneumococcal polysaccharide, still failed to show a response when older-ie, when such responses are the norm. Ongoing immunosuppression prevents the maturation of antipolysaccharide responses leaving children susceptible to severe and recurrent damaging infection.

The susceptibility of normal, healthy children to infection has long been recognized, but the underlying mechanisms are poorly understood. As adequate cytokine production is crucial for optimal immune responses, we assessed antigen and mitogen-induced cytokine production in healthy children. Our results demonstrate that healthy children differ markedly compared with adults in their ability to produce cytokines (IL-2, interferon-gamma, IL-4, and IL-6). Maximal stimulation with mitogen demonstrated impaired cytokine production with markedly lower levels of all four cytokines produced compared with adult levels. When stimulated with antigens, median levels of IL-2 and IL-4 remained lower than adult values, IL-6 production was increased as was interferon-gamma, albeit not significantly. Although the study was carried out on peripheral blood mononuclear cells that represent a restricted compartment of the immune system, these data suggest that, in healthy children, cytokine production is decreased and/or altered and could result in a suboptimal immune response, which could be one of the factors underlying increased susceptibility to infection in children.