Langhans giant cells from M. tuberculosis-induced human granulomas cannot mediate mycobacterial uptake

Tuberculosis is characterized by a tight interplay between Mycobacterium tuberculosis (M. tb) and host cells within granulomas. These cellular aggregates restrain M. tb spreading but do not kill all bacilli, which persist for years. A more detailed investigation of the interaction between M. tb and granuloma cells is needed to improve our understanding of this persistence and to explain the physiopathology of tuberculosis. In the present study, a recently developed in vitro human model of tuberculous granulomas has been used to analyse the modulation of granuloma cell differentiation by M. tb, in comparison to poorly virulent mycobacteria, which do not persist. It is reported that whilst all mycobacteria species induce granuloma formation, only M. tb triggers the differentiation of granuloma macrophages into very large multinucleated giant cells (MGCs) that are unable to mediate any bacterial uptake. This loss of function is not due to cell quiescence, as MGCs still display NADPH oxidase activity, but it correlates with decreased expression of phagocytosis receptors. This phenomenon is specific for the virulent species of M. tuberculosis complex, as poorly virulent species only induce the formation of small multinucleated cells (MCs) with conserved mycobacterial uptake ability, which never reach the MGC differentiation stage. The phenotype of MGCs thus strongly resembles mature dendritic cells with a loss of microbial uptake ability, despite conserved antigen presentation. In M. tb-induced granulomas, MGCs thus seem to be devoted to the destruction of bacilli that have been ingested in previous differentiation stages, ie in macrophages and MCs.

Hypothalamo-hypophysial dysfunction after traumatic brain injury in children and adolescents: a preliminary retrospective and prospective study

With two study protocols, one retrospective and the other prospective, we evaluated hypothalamo-hypophysial dysfunction (HHD) in paediatric patients treated for traumatic brain injury (TBI) in the neurosurgical or intensive care department at our hospital. The retrospective group comprised 22 patients who had experienced TBI 0.7-7.25 years before the study. The prospective group included 30 patients assessed at TBI (T0), 26 of 30 after 6 months (T6), and 20 of 26 after 12 months (T12). Auxological and hormonal basal parameters of hypothalamo-hypophysial function were evaluated at recall in the retrospective group, and at T0, T6 and T12 in the prospective group. Basal data and standard dynamic tests in selected patients revealed one with precocious puberty, one with total anterior hypopituitarism, one with central hypogonadism, and one with growth hormone (GH) deficiency in the retrospective group; three patients with cerebral salt-wasting syndrome, one with diabetes insipidus and seven with low T3 syndrome at T0 (all transient), one with hypocorticism at T6 confirmed at T12, and one with GH deficiency at T12 in the prospective group. The results of our study show that post-TBI HHD in our paediatric cohort is not uncommon. Of the 48 patients who underwent a complete evaluation (22 retrospective study patients and 26 prospective study patients evaluated at T6) five (10.4%) developed HHD 6 months or more after TBI. HHD was newly diagnosed in one previously normal patient from the prospective group at 12 months after TBI. GH deficiency was the most frequent disorder in our paediatric cohort.

A high neonatal serum eosinophil cationic protein level is a risk factor for atopic symptoms

AIM

To show whether neonatal eosinophil counts (EC) and eosinophil cationic protein (ECP) can be used in assessing the risk of atopy, alone or in combination with family history of atopy (FHa).

PATIENTS AND METHODS

A group of 63 newborns was included: 38 with FHa, 25 without FHa. A blood sample was collected on the 4th day of life for EC and ECP evaluation. Clinical follow-up was conducted after 1, 3, 6, 12, 18, 24 and 36 mo. The chi2 test and the Student's t-test were used to compare dichotomic and continuous variables, respectively. Variables shown to be significant by univariate analysis were evaluated with a multivariate regression model and the relative risks (RR) were estimated.

RESULTS

Twenty-six newborns (41%) displayed atopic manifestations during the follow-up. Twenty-one (55%) of 38 newborns with FHa displayed atopic symptoms versus 5/25 (20%) without FHa (p 0.012). Neither EC nor serum ECP levels were significantly different between newborns with FHa and newborns without. ECP levels did not differ between newborns with single heredity and newborns with dual heredity. EC did not differ significantly between newborns who developed atopy and those who did not. Instead, serum ECP levels were significantly higher in newborns who developed atopy (mean 27.9 microU/l vs 16.8 microU/l). Atopic manifestations appeared in 16 (62%) of 26 newborns with ECP > or = 18 microU/l compared with 10 (27%) of 37 with ECP < 18 microU/l (p = 0.006). In the multivariate regression model, with ECP < 18 microU/l and no FHa as reference class, the class 1 (no FHa and ECP > or = 18 microU/l) has a low RR (1.4), class 2 (FHa and ECP < 18 microU/l) an intermediate RR (2.7) and class 3 (FHa and ECP > or = 18 microU/l) a very high RR (16.3).

CONCLUSIONS

Neonatal serum ECP levels, in contrast with EC, were significantly higher in newborns who developed atopic manifestations during follow-up. The risk of atopy was about twice as great when ECP was > or = 18 microU/l (and four times as great in multivariate analysis). When serum ECP was combined with FHa, the RR for newborns with FHa and ECP > or = 18 microU/l was 16 times greater than for those without FHa and ECP < 18 microU/l. The identification of newborns at "extremely high atopic risk" (FHa and ECP > or = 18 microU/l) may be expecially useful--in clinical practice--in newborns with only one atopic parent or sibling, for whom it is not universally agreed that dietary and environmental prevention measures should be applied.

Pamidronate treatment in bone fibrous dysplasia in children and adolescents with McCune-Albright syndrome

Thirteen patients with McCune-Albright syndrome (MAS) and bone fibrous dysplasia (BFD) have been treated for 2-6 years with pamidronate, an aminobisphosphonate which inhibits osteoclastic function. MAS is a rare genetic condition caused by constitutive activating mutations of the Gs protein and manifests with skin dysplasia, bone fibrous dysplasia, and multiple endocrinopathies. Raised serum alkaline phosphatase and urinary hydroxyproline have been reported in these patients, indicating bone metabolic hyperactivity. Encouraging therapeutic results have been achieved with pamidronate, mainly in adults. In our study, treatment reduced bone pain, fracture rate and metabolic indices of bone turnover, in particular significantly decreased bone alkaline phosphatase and cross-links (Wilcoxon test; p <0.06), and increased bone mineral density (DEXA). Signs of healing, such as thickening of the cortical bone, were found in some patients. Three patterns of MRI were found: homogeneous hypointense fibrous tissue, 'dotted' hypointense fibrous tissue, and hyperintense cystic images. Pamidronate treatment can be considered a favorable therapeutic option for patients with MAS.

Interleukin-12 receptor beta1 deficiency in a patient with abdominal tuberculosis

Two siblings with interleukin-12 receptor beta1 (IL-12Rbeta1) deficiency but different clinical phenotypes were studied. Both are homozygous for an IL12RB1 missense mutation that prevents receptor expression and abolishes cellular responses to IL-12. Transfection of the patients' T cells with wild-type IL12RB1 restored IL-12Rbeta1 expression and function. One patient had the expected phenotype of disseminated bacille Calmette-Guérin (BCG) infection in early childhood, whereas the other did not develop BCG infection, despite 3 inoculations with live BCG. Abdominal tuberculosis was diagnosed in this second patient at age 18 years. To date, neither of them has had clinical disease caused by environmental mycobacteria. These observations show unexpected interfamilial and intrafamilial heterogeneity of the clinical phenotype associated with IL-12Rbeta1 deficiency. The patients may be resistant to BCG but remain vulnerable to Mycobacterium tuberculosis. A diagnosis of IL-12Rbeta1 deficiency should therefore be considered in selected patients with severe tuberculosis, despite their resistance to BCG and a lack of atypical mycobacteriosis.

Thyroid diseases in patients treated during pre-puberty for medulloblastoma with different radiotherapic protocols

We evaluated thyroid disease in 32 patients treated, during pre-puberty, for medulloblastoma, followed for at least 4 years and without relapse during observation. After surgery the patients underwent chemotherapy (CT) and radiotherapy (RT). The protocols were as follows: 20 patients (group A) SNC 76 and SNC 85 protocols which included conventional fractionated RT (36-40 Gy to the craniospinal axis and a 14-18 Gy boost to the posterior fossa, administered as 1.5-1.8 Gy per fraction per day) and a junction between the cranial and the spinal fields at C2-C3 level; 12 patients (group B) SNC 91 protocol which included hyperfractionated RT (36 Gy to the craniospinal axis and a 30 Gy boost to the posterior fossa; this was administred as 1 Gy per fraction twice per day) and a junction at levels C5-C6 or C6-C7 level. The mean age at diagnosis was 7.4+/-3.2 years for group A and 8.4+/-2.6 years for group B. Thyroid function was evaluated yearly and ultrasonographic characteristics every 2 years. The patients were followed for a mean of 10.8+/-3.8 for group A and 6+/-1.4 years for group B. Primary hypothyroidism was diagnosed in 16 group A patients and 4 group B patients, and central hypothyroidism was diagnosed in 2 group A patients (difference in risk of developing hypothyroidism evaluated with a Wilcoxon-test: p=0.048). Ultrasonography showed reduced thyroid volume in 7 group A cases, and structural changes in 21 patients (17 group A, 4 group B); 9 L-thyroxine-treated patients were confirmed hypothyroid after having stopped therapy. A thyroid nodule was detected in two cases (one from each group). In conclusion, our data indicate that thyroid injury may be diminished by the use of hyperfractionation and low-junction radiotherapy in the treatment of medulloblastoma.

Mycobacterium fortuitum-chelonae complex infection in a child with complete interleukin-12 receptor beta 1 deficiency

A 10-year-old boy had chronic diarrhea, abdominal pain, severe weight loss and hepatomegaly; multiple enlarged para-aortic and mesenteric lymph nodes. Mycobacterium fortuitum-chelonae complex was identified in the culture of the lymph nodes. Interleukin-12 receptor beta 1 expression could not be observed in phytohemagglutinin-driven T cell blasts. A homozygous missense interleukin-12 receptor beta 1 mutation was found (R173P).

Human interferon-gamma-mediated immunity is a genetically controlled continuous trait that determines the outcome of mycobacterial invasion

Individuals with inherited disorders of interferon gamma (IFN-gamma)-mediated immunity appear to be specifically vulnerable to mycobacterial infections. The severity of clinical features of affected individuals differs between cases. Some patients die of mycobacterial infection in early childhood, whereas others have long asymptomatic periods in childhood and as adults. This rare syndrome also shows high allelic and non-allelic genetic heterogeneity. Mutations in IL12B, encoding the interleukin (IL)-12 p40 subunit, and in IL12RB1, encoding the beta1 chain of the IL-12 receptor, result in impaired IFN-gamma production. Mutations in IFNGR1 and IFNGR2, encoding the two IFN-gamma receptor chains, and mutations in STAT1, encoding an essential signaling component, result in impaired cellular responses to IFN gamma. Different types of mutation define two types of complete and two types of partial IFNgammaR1 deficiency. Complete and partial IFNgammaR2 deficiency have also been described. We herein compare the genotypes, cellular phenotypes, and clinical phenotypes of healthy individuals and patients with the seven known genetic disorders impairing cellular responses to IFN-gamma. Patients with defective IFN-gamma production were not considered in this study. The mutations and clinical features of patients with IFNgammaR1, IFNgammaR2, and STAT-1 deficiency are reviewed. Selected cell lines from each of the eight groups were tested for their response to IFN-gamma. We find that individuals may be classified into four broad groups based on genotype, cellular phenotype, and clinical phenotype (normal individuals and patients with mild, intermediate, or severe disease). This correlation suggests that IFN-gamma-mediated cell activation is a genetically controlled quantitative trait and that it determines the outcome of mycobacterial invasion in man.

Genetic heterogeneity of Mendelian susceptibility to mycobacterial infection

Mendelian susceptibility to poorly virulent mycobacterial species, such as bacillus Calmette-Guérin (BCG) and environmental nontuberculous mycobacteria (NTM), is a phenotypically heterogeneous syndrome. It has therefore long been suspected to be genetically heterogeneous. In the past 5 years, this prediction has been confirmed and different types of mutations (dominant or recessive, nonfunctional or hypofunctional) in four genes (IFNGR1, IFNGR2, IL12B, IL12RB1) have revealed both allelic and nonallelic heterogeneity. The eight disorders resulting from these mutations are genetically different but immunologically related, as impaired IFN-gamma-mediated immunity is the common pathogenic mechanism accounting for mycobacterial infection in all patients. The severity of the phenotype depends on the genotype. Complete IFN-gammaR1 and IFN-gammaR2 deficiencies predispose patients to a more severe clinical course than partial IFN-gammaR1 and IFN-gammaR2 deficiencies and complete IL-12 p40 and IL-12Rbeta1 deficiencies.

Impairment of STAT activation by IL-12 in a patient with atypical mycobacterial and staphylococcal infections

IL-12 plays a pivotal role in the stimulation of immune responses against intracellular infections. This role is manifested in the increased susceptibility to atypical mycobacterial and salmonella infections among individuals whose lymphocytes lack expression of IL-12Rbeta1. Here, we report on a patient with Mycobacterium avium infection, recurrent Staphylococcus aureus sinusitis, and multiple adverse drug reactions whose T cells were unable to produce IFN-gamma or proliferate in response to IL-12 despite the expression of wild-type IL-12Rbeta1 and IL-12Rbeta2. The defect in these functional responses to IL-12 was selective, as cytolytic activity induced by IL-12 was intact, and lymphocytes were responsive to stimulation by IL-2. An examination of cytokine signaling revealed that STAT4 and extracellular regulated kinase 1 (ERK1) activation by IL-12 was intact, whereas the activation of STAT1, -3, and -5 by IL-12 was lost. This impairment of STAT activation was specific for IL-12, as STAT activation by IL-2, IL-15, and IFN-gamma was unaffected. These findings demonstrate that the activation of STAT4 alone is not sufficient for IL-12-induced IFN-gamma production and proliferation and suggest that other STATs play a role in these responses to IL-12. While the etiology of the impaired IL-12 signaling in this patient has not yet been elucidated, the absence of mutations in IL-12Rbeta1 or IL-12Rbeta2 and the preservation of STAT4 activation raise the possibility that there may be a mutation in an as yet undiscovered component of the IL-12 signaling complex that is normally required for the recruitment and activation of STAT1, -3, and -5.

In a novel form of IFN-gamma receptor 1 deficiency, cell surface receptors fail to bind IFN-gamma

Complete IFN-gamma receptor ligand-binding chain (IFNgammaR1) deficiency is a life-threatening autosomal recessive immune disorder. Affected children invariably die of mycobacterial infection, unless bone marrow transplantation is undertaken. Pathogenic IFNGR1 mutations identified to date include nonsense and splice mutations and frameshift deletions and insertions. All result in a premature stop codon upstream from the segment encoding the transmembrane domain, precluding cell surface expression of the receptors. We report herein two sporadic and two familial cases of a novel form of complete IFNgammaR1 deficiency in which normal numbers of receptors are detected at the cell surface. Two in-frame deletions and two missense IFNGR1 mutations were identified in the segment encoding the extracellular ligand-binding domain of the receptor. Eight independent IFNgammaR1-specific mAb's, including seven blocking antibodies, gave recognition patterns that differed between patients, suggesting that different epitopes were altered by the mutations. No specific binding of (125)I-IFN-gamma to cells was observed in any patient, however, and the cells failed to respond to IFN-gamma. The mutations therefore cause complete IFNgammaR1 deficiency by disrupting the IFN-gamma-binding site without affecting surface expression. The detection of surface IFNgammaR1 molecules by specific antibodies, including blocking antibodies, does not exclude a diagnosis of complete IFNgammaR1 deficiency.

Partial interferon-gamma receptor signaling chain deficiency in a patient with bacille Calmette-Guérin and Mycobacterium abscessus infection

Complete deficiency of either of the two human interferon (IFN)-gamma receptor components, the ligand-binding IFN-gammaR1 chain and the signaling IFN-gammaR2 chain, is invariably associated with early-onset infection caused by bacille Calmette-Guérin vaccines and/or environmental nontuberculous mycobacteria, poor granuloma formation, and a fatal outcome in childhood. Partial IFN-gammaR1 deficiency is associated with a milder histopathologic and clinical phenotype. Cells from a 20-year-old healthy person with a history of curable infections due to bacille Calmette-Guérin and Mycobacterium abscessus and mature granulomas in childhood were investigated. There was a homozygous nucleotide substitution in IFNGR2, causing an amino acid substitution in the extracellular region of the encoded receptor. Cell surface IFN-gammaR2 were detected by flow cytometry. Cellular responses to IFN-gamma were impaired but not abolished. Transfection with the wild-type IFNGR2 gene restored full responsiveness to IFN-gamma. This is the first demonstration of partial IFN-gammaR2 deficiency in humans.

IL-12 and IFN-gamma in host defense against mycobacteria and salmonella in mice and men

The development of gene-knockout mice and the identification of gene-deficient humans have improved our understanding of the role of IL-12 and IFN-gamma in host defense. Comparison of experimental and natural infections has shown that animals and humans genetically deficient in immunity mediated by IL-12 or IFN-gamma are highly susceptible to mycobacteria and salmonella. Impaired secretion of, or response to, IFN-gamma is the common pathogenic mechanism that accounts for impaired granuloma formation and uncontrolled growth of bacteria within macrophages. The axis formed between IL-12 and IFN-gamma is essential for protective immunity against mycobacteria and salmonella in mice and men.

A human IFNGR1 small deletion hotspot associated with dominant susceptibility to mycobacterial infection

The immunogenetic basis of severe infections caused by bacille Calmette-Guérin vaccine and environmental mycobacteria in humans remains largely unknown. We describe 18 patients from several generations of 12 unrelated families who were heterozygous for 1 to 5 overlapping IFNGR1 frameshift small deletions and a wild-type IFNGR1 allele. There were 12 independent mutation events at a single mutation site, defining a small deletion hotspot. Neighbouring sequence analysis favours a small deletion model of slipped mispairing events during replication. The mutant alleles encode cell-surface IFNgamma receptors that lack the intra-cytoplasmic domain, which, through a combination of impaired recycling, abrogated signalling and normal binding to IFNgamma exert a dominant-negative effect. We thus report a hotspot for human IFNGR1 small deletions that confer dominant susceptibility to infections caused by poorly virulent mycobacteria.

Inherited interleukin 12 deficiency in a child with bacille Calmette-Guérin and Salmonella enteritidis disseminated infection

Interferon-gamma receptor ligand-binding chain (IFN-gammaR1) or signaling chain (IFN-gammaR2) deficiency, like interleukin 12 receptor beta1 chain (IL-12Rbeta1) deficiency, predispose to severe infections due to poorly virulent mycobacteria and salmonella. A child with bacille Calmette-Guérin and Salmonella enteritidis infection was investigated. Mutations in the genes for IFN-gammaR1, IFN-gammaR2, IL-12Rbeta1, and other molecules implicated in IL-12- or IFN-gamma-mediated immunity were sought. A large homozygous deletion within the IL-12 p40 subunit gene was found, precluding expression of functional IL-12 p70 cytokine by activated dendritic cells and phagocytes. As a result, IFN-gamma production by lymphocytes was markedly impaired. This is the first discovered human disease resulting from a cytokine gene defect. It suggests that IL-12 is essential to and appears specific for protective immunity to intracellular bacteria such as mycobacteria and salmonella.

Mendelian susceptibility to mycobacterial infection in man

Selective susceptibility to poorly pathogenic mycobacteria, such as bacille Calmette-Guérin vaccine and environmental non-tuberculous mycobacteria, has long been suspected to be a mendelian disorder but its molecular basis has remained elusive. Recently, recessive mutations in the interferon-gamma-receptor receptor ligand-binding chain, interferon-gamma-receptor signalling chain, IL-12 p40 subunit and IL-12-receptor beta 1 chain genes have been identified in a number of patients with disseminated mycobacterial infection. Although genetically distinct, these conditions are immunologically related and highlight the essential role of interferon-gamma-mediated immunity in the control of mycobacteria in man.

Severe mycobacterial and Salmonella infections in interleukin-12 receptor-deficient patients

Interleukin-12 (IL-12) is a cytokine that promotes cell-mediated immunity to intracellular pathogens by inducing type 1 helper T cell (TH1) responses and interferon-gamma (IFN-gamma) production. IL-12 binds to high-affinity beta1/beta2 heterodimeric IL-12 receptor (IL-12R) complexes on T cell and natural killer cells. Three unrelated individuals with severe, idiopathic mycobacterial and Salmonella infections were found to lack IL-12Rbeta1 chain expression. Their cells were deficient in IL-12R signaling and IFN-gamma production, and their remaining T cell responses were independent of endogenous IL-12. IL-12Rbeta1 sequence analysis revealed genetic mutations that resulted in premature stop codons in the extracellular domain. The lack of IL-12Rbeta1 expression results in a human immunodeficiency and shows the essential role of IL-12 in resistance to infections due to intracellular bacteria.

Impairment of mycobacterial immunity in human interleukin-12 receptor deficiency

In humans, interferon gamma (IFN-gamma) receptor deficiency leads to a predisposition to mycobacterial infections and impairs the formation of mature granulomas. Interleukin-12 (IL-12) receptor deficiency was found in otherwise healthy individuals with mycobacterial infections. Mature granulomas were seen, surrounded by T cells and centered with epithelioid and multinucleated giant cells, yet reduced IFN-gamma concentrations were found to be secreted by activated natural killer and T cells. Thus, IL-12-dependent IFN-gamma secretion in humans seems essential in the control of mycobacterial infections, despite the formation of mature granulomas due to IL-12-independent IFN-gamma secretion.

Interferon-gamma receptor deficiency: relationship between genotype, environment, and phenotype (Review)

Interferon-gamma receptor ligand binding chain (IFNgammaR1) deficiency is an autosomal recessive inherited immune disorder. Mutations in the IFNgR1 gene are associated with severe infections due to mycobacteria. However, several aspects of the phenotype of IFNgammaR1-deficient children have recently been found to vary from case to case. This review thus discusses the respective roles of the genotype and of the environment in determining phenotypic variations among affected children.

Partial interferon-gamma receptor 1 deficiency in a child with tuberculoid bacillus Calmette-Guérin infection and a sibling with clinical tuberculosis

Complete interferon-gamma receptor 1 (IFNgammaR1) deficiency has been identified previously as a cause of fatal bacillus Calmette-Guérin (BCG) infection with lepromatoid granulomas, and of disseminated nontuberculous mycobacterial (NTM) infection in children who had not been inoculated with BCG. We report here a kindred with partial IFNgammaR1 deficiency: one child afflicted by disseminated BCG infection with tuberculoid granulomas, and a sibling, who had not been inoculated previously with BCG, with clinical tuberculosis. Both responded to antimicrobials and are currently well without prophylactic therapy. Impaired response to IFN-gamma was documented in B cells by signal transducer and activator of transcription 1 nuclear translocation, in fibroblasts by cell surface HLA class II induction, and in monocytes by cell surface CD64 induction and TNF-alpha secretion. Whereas cells from healthy children responded to even low IFN-gamma concentrations (10 IU/ml), and cells from a child with complete IFNgammaR1 deficiency did not respond to even high IFN-gamma concentrations (10,000 IU/ml), cells from the two siblings did not respond to low or intermediate concentrations, yet responded to high IFN-gamma concentrations. A homozygous missense IFNgR1 mutation was identified, and its pathogenic role was ascertained by molecular complementation. Thus, whereas complete IFNgammaR1 deficiency in previously identified kindreds caused fatal lepromatoid BCG infection and disseminated NTM infection, partial IFNgammaR1 deficiency in this kindred caused curable tuberculoid BCG infection and clinical tuberculosis.

Infections in IFNGR-1-deficient children

Human interferon-gamma receptor 1 (IFNGR-1) deficiency is a newly identified autosomal recessive inherited immune disorder. Children with IFNGR-1 deficiency exhibit a severe, profound and selective susceptibility to weakly virulent mycobacteria, such as bacillus Calmette-Guerin (BCG) vaccine or environmental nontuberculous mycobacteria (NTM). This review compares the infections found in IFNGR-1-deficient children to those in IFN-gamma-deficient or IFNGR-1-deficient mice.

Fatal disseminated Mycobacterium smegmatis infection in a child with inherited interferon gamma receptor deficiency

Mycobacterium smegmatis is a common environmental mycobacterium that was first identified in 1884, yet is a rare pathogen in humans. The few M. smegmatis infections reported to date have been localized and have occurred in association with a primary lesion in otherwise immunocompetent individuals. To our knowledge, no case of disseminated M. smegmatis infection has ever been reported, even in patients with severe immune deficiencies. We report a case of disseminated mycobacterial infection that was diagnosed in a 3-year-old girl. The pathogen was not identified as M. smegmatis until the patient was 6 years old. Her condition gradually worsened, and she died when she was 8 years old despite appropriate antimycobacterial therapy. No other opportunistic infections were documented. Immunological investigations revealed an inherited interferon gamma receptor 1 deficiency. This report identifies M. smegmatis as a new opportunistic agent that may be responsible for disseminated disease in immunocompromised individuals.

Evidence for an interaction between alpha-MSH and opioids in the regulation of gonadotropin secretion in man

Gonadotropin secretion is inhibited by the endogenous opioids and stimulated by their antagonist naloxone. LH secretion is stimulated by alpha-MSH, a tridecapeptide derived from the post-translational processing of POMC. The possibility that alpha-MSH interacts with the opioids, as suggested by the experimental evidence, was investigated in 7 normal males aged 24-29 through the performance of seven tests: naloxone (0.8 mg i.v. bolus, followed by infusion of 1.6 mg/h for 120'); alpha-MSH (2.5 mg i.v. bolus); naloxone + alpha-MSH (2.5 mg i.v. 15' after commencement of the naloxone infusion); naloxone + GnRH (100 micrograms i.v. 15' after commencement of the naloxone infusion); alpha-MSH + GnRH (respectively 2.5 mg and 100 micrograms at time 0), GnRH alone (100 micrograms at time 0), placebo (150 nmol/l NaCl solution). The LH AUCs during both naloxone (30.3 +/- 2.7 mIU/ml.min-1) and alpha-MSH test (32.9 +/- 4.6 mIU/ml.min-1) were significantly greater (p < 0.005) than that observed during placebo (16.9 +/- 3.6 mIU/ml.min-1). The LH AUC during alpha-MSH + naloxone (37.6 +/- 2.6 mIU/ml.min-1) was not significantly different from that recorded during their separate administration. GnRH injected alone, during the naloxone infusion and with alpha-MSH produced similar increases in LH, that were significantly higher than that observed during the other tests (AUCs: GnRH 89.4 +/- 10.6, GnRH + naloxone 100.5 +/- 9.1, GnRH + alpha-MSH 94.6 +/- 7.9 mIU/ml.min-1, p < 0.001). Significant increase in FSH (p < 0.001) was only observed during GnRH, GnRH + naloxone and GnRH + aMSH tests (AUCs: placebo 13.3 +/- 1.7; naloxone 14.7 +/- 2.5; alpha-MSH 15.5 +/- 2.3; alpha-MSH + naloxone 16.9 +/- 1.9; GnRH 19.1 +/- 1.1; GnRH + alpha-MSH 20.7 +/- 1.3; GnRH + naloxone 21.2 +/- 1.8 mIU/ml.min-1). These results are in line with the possibility of an interaction between alpha-MSH and the opioids in the regulation of gonadotropin secretion, perhaps with opposing effects on a final common pathway.

Correlation of granuloma structure with clinical outcome defines two types of idiopathic disseminated BCG infection

Bacillus Calmette Guérin (BCG) is an attenuated strain of Mycobacterium bovis that is currently used as a live vaccine for human tuberculosis. Disseminated BCG infection may rarely occur following vaccination of children. In half of the cases, regarded as idiopathic, no well-defined immunodeficiency condition can account for the infection. However, the high rates of parental consanguinity and familial forms and the associated opportunistic infections with Salmonella suggest that these idiopathic BCG infections result from one or several new type(s) of inherited immune disorder(s). As an approach to the description and understanding of this newly described condition, the associated lesions were examined. Samples from 14 patients collected from a French national retrospective study were analysed. Pathological data from 22 cases reported in the world literature were also reviewed. Two types of granuloma were found. The first type (type I, tuberculoid) consisted of well-circumscribed and well-differentiated granulomas, with epithelioid and multinucleated giant cells containing very few acid-fast rods, surrounded by lymphocytes and fibrosis and occasionally with central caseous necrosis. The second type (type II, lepromatous-like) consisted of ill-defined and poorly differentiated granulomas, with few if any giant cells and lymphocytes but widespread macrophages loaded with acid-fast bacilli. Most children displayed a single type of granuloma. One half displayed type 1 lesions and the other half displayed type II lesions. There was a strong correlation between the type of granuloma and the clinical outcome. Tuberculoid lesions were associated with survival, whilst lepromatous-like lesions correlated with death. Correlation of granuloma structure with clinical outcome defines two types of idiopathic disseminated BCG infection. The phenotypic heterogeneity of the course of BCG infection reflects distinct pathogenic mechanisms and probably results from a genotypic heterogeneity of the underlying inherited immune disorder.

Idiopathic disseminated bacillus Calmette-Guérin infection: a French national retrospective study

OBJECTIVE

Disseminated bacillus Calmette-Guérin (BCG) infection after inoculation of live vaccine is considered to result from impaired immunity of the child. However, in half of the cases, regarded as idiopathic, no well-defined immunodeficiency condition can account for the infection. The objective of the present study is to report the prevalence, clinical features, associated infections, and outcomes of children with idiopathic disseminated BCG infection.

DESIGN

National retrospective survey during the period from 1974 through 1994 in France.

SETTING

All neonatology and pediatrics units in primary care and referral centers throughout France.

PATIENTS

Data were collected from 595 (82%) of 721 units, 377 (93%) of 407 centers, and 320 (93%) of 345 cities. Selection criteria included BCG infection, dissemination to at least two areas beyond the inoculation site, and no well-defined immunodeficiency condition. Sixteen children (8 girls and 8 boys), born to families unrelated to each other but often consanguinous (5 of 16) or abroad (5 of 16).

RESULTS

The minimal prevalence rate was estimated at 0.59 cases per 1 million vaccinated children born in France. Clinical features included fever and cachexia, disseminated BCG infection to lymph nodes (15 of 16), skin (13 of 16), soft tissues (11 of 16), lungs (11 of 16), spleen (11 of 16), liver (11 of 16), and bones (9 of 16). Eight children had associated or subsequent severe opportunistic infection (50%), with either nontyphi Salmonella enterica serotypes (7 of 16) or Mycobacterium abscessus (1 of 16). The outcome was poor: 8 children (50%) died; the cause of death was BCG infection for most children (7 of 8); 8 survived until the last follow-up (50%).

CONCLUSIONS

Idiopathic disseminated BCG infection is a rare but severe complication of BCG vaccination. The infection probably results from an as yet unknown genetically determined immunodeficiency condition that affects the killing of intracellular bacteria such as BCG and Salmonella.

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

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

Hematological studies in children with Down syndrome

Previous studies have reported erythrocyte macrocytosis in adults and children with Down syndrome (DS), the significance of which remains unclear. We compared hematological parameters of 50 DS children aged 2 to 15 years, divided into three age groups, with those of 68 aged-matched healthy children. Patients with DS had a significantly increased mean corpuscular volume (MCV) and hemoglobin in all groups when compared with the controls. Erythrocyte creatine content, hexokinase (Hk) activity, erythrocyte and serum folates, vitamin B12, haptoglobin, serum iron, and ferritin were tested. All of these parameters were not significantly different from those of the control group. We conclude that macrocytosis may not be an expression of reduced red cell survival but rather of an altered folate remethylation pathway, secondary to enhanced cystathionine beta-synthase (CBS) activity, the gene for which is present on chromosome 21.

Serum pepsinogen I in childhood Helicobacter pylori gastritis: its relation to mucosal peptic activity

Serum pepsinogen I (PG I) levels are raised in children with Helicobacter pylori gastritis. To ascertain if this is due to increased production or to increased secretion of pepsin by chief cells, we measured mucosal peptic activity in antrum and gastric body mucosal homogenates and correlated it to serum PG I levels in 122 children with and without H. pylori gastritis. In patients infected with H. pylori, mucosal peptic activity was decreased when compared to control and to children with non H. pylori gastritis. Serum PG I levels were increased (P < 0.001) and were inversely related to mucosal peptic activity (P < 0.01). These findings suggest that H. pylori can promote a leakage of pepsinogen into the circulation.

Expression cloning of a protective Leishmania antigen

Parasite-specific CD4+ T cells have been shown to transfer protection against Leishmania major in susceptible BALB/c mice. An epitope-tagged expression library was used to identify the antigen recognized by a protective CD4+ T cell clone. The expression library allowed recombinant proteins made in bacteria to be captured by macrophages for presentation to T cells restricted to major histocompatibility complex class II. A conserved 36-kilodalton member of the tryptophan-aspartic acid repeat family of proteins was identified that was expressed in both stages of the parasite life cycle. A 24-kilodalton portion of this antigen protected susceptible mice when administered as a vaccine with interleukin-12 before infection.

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

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

Differential effects of oral conjugated estrogens and transdermal estradiol on insulin-like growth factor 1, growth hormone and sex hormone binding globulin serum levels

In postmenopausal women oral ethinylestradiol causes a reduction in circulating insulin-like growth factor 1 (IGF-1) and an increase in serum growth hormone levels. There are no data on the effect of conjugated estrogens, the preparation most often used in estrogen replacement treatment (ERT), on these parameters. We evaluated serum IGF-1 and growth hormone levels, together with the levels of sex hormone binding globulin (SHBG), an indicator of estrogen hepatocellular action, before and after 6 months of ERT in two comparable groups of postmenopausal women. Sixteen women were treated with oral conjugated estrogens, 0.625 mg/day, and 14 with transdermal estradiol, 0.05 mg/day. In the women treated with oral conjugated estrogens, an increase in SHBG (p < 0.001), a decrease in IGF-1 (p < 0.001) and an increase in growth hormone (p < 0.05) serum levels were observed. No such effects were seen with the use of transdermal estradiol, devoid of hepatocellular effects. Undoubtedly, oral conjugated estrogens, 0.625 mg/day, through a hepatocellular effect, cause marked modifications in the IGF-1/growth hormone axis, which may have clinical relevance. For instance, the decreased IGF-1 level, together with the increased level of SHBG, might provide some explanation of the favorable epidemiological data on breast cancer risk in women receiving oral conjugated estrogens.

Eighteen month follow up of Helicobacter pylori positive children treated with amoxycillin and tinidazole

Sixty three children with dyspepsia (mean age 12 years, range one to 18, M/F 41/22) were Helicobacter pylori positive by histology of gastric antral biopsy specimens and were treated with a six week course of amoxycillin (50 mg/kg) and tinidazole (20 mg/kg). The endoscopic diagnoses were: normal (16), nodular gastritis (19), oesophagitis (four), duodenal ulcer (13), and gastric ulcer (11). H pylori was eradicated in 54 (87%) and histological gastritis resolved in 51 and was improved in the other three. Repeat investigation was offered at six monthly intervals. Reinfection was found in three of 34 (9%) at six months, in none of 22 at 12 months, and in two of 18 (11%) at 18 months, yielding an 18 month cumulative relapse rate of 20%. Children with persisting infection despite treatment remained positive during follow up. Serum H pylori IgG concentrations fell after treatment (p < 0.001), and for individual children during follow up there was a progressive decline, but an increased concentration indicated recurrence. After eradication of H pylori by combined amoxycillin and tinidazole treatment, only a minority of children relapse during the ensuing 18 months.

Helicobacter pylori in children with peptic ulcer and their families

Little is known about the source and spread of Helicobacter pylori, but transmission from infected family contacts has been suggested. We have therefore investigated 15 children with peptic ulcer and their first-degree relatives for H. pylori. Serum anti-H. pylori IgG, pepsinogen I, and gastrin levels were measured. Endoscopy was carried out on the children and relatives, and biopsies were taken from the gastric antrum for histology, microbiology, and urease testing. Six of 11 children with duodenal ulcer (55%) and two of four children with gastric ulcer (50%) were positive for H. pylori. Fourteen of 16 parents (87%) and eight of 13 siblings (61%) of H. pylori-positive children with peptic ulcer were also infected compared with eight of 14 parents (57%) and none of four siblings of H. pylori-negative children with peptic ulcer (P less than 0.10, greater than 0.05, and NS, respectively). The children with H. pylori-negative peptic ulcer and negative siblings combined were younger than positive children with peptic ulcer and positive siblings (P less than 0.001). The reliability of serum anti-H. pylori IgG level as a screening test for infection was confirmed. These findings call into question a pathogenetic role for H. pylori in some childhood peptic ulceration, but do suggest that person-to-person spread of infection occurs.

Serum pepsinogen I and gastrin concentrations in children positive for Helicobacter pylori

Serum pepsinogen I, serum gastrin concentration, and inflammatory scores were measured in a population of 71 children undergoing upper gastrointestinal endoscopy for investigation of upper abdominal pain. Forty four were initially colonised with Helicobacter pylori. The indices were measured before treatment (in 71 children), one month (in 41 children), and six months (in 21 children) after stopping treatment. Before treatment there was a significant correlation between serum pepsinogen concentration, total inflammatory score, and H pylori state, but no correlation between serum gastrin concentrations and H pylori state. Similarly, the total inflammatory score and serum pepsinogen concentrations were significantly correlated. There was no such correlation in children negative for H pylori. After treatment the inflammatory score improved in those patients in whom H pylori had been eradicated. There was also a significant fall in serum pepsinogen I and serum gastrin concentration in those patients in whom H pylori had been eradicated. These results were similar to those found six months after treatment had been stopped. These findings suggest that the serum pepsinogen I concentration could be considered a useful marker for gastritis and can be used as an index of severity of gastritis in H pylori positive subjects. The measurement of serum gastrin concentrations does not give useful information.

Amoxycillin plus tinidazole for Campylobacter pylori gastritis in children: assessment by serum IgG antibody, pepsinogen I, and gastrin levels

32 children (mean age 12 years, range 6-18) with non-specific abdominal pain and Campylobacter pylori positive gastritis received a six week course of daily oral amoxycillin (50 mg/kg) and tinidazole (20 mg/kg). Before treatment and one month after stopping treatment, endoscopic biopsy samples were taken from the antral mucosa and serum C pylori IgG antibody, pepsinogen I, and gastrin levels were measured in fasting blood samples. One month after treatment 30 children (94%) were cleared of C pylori and gastritis had resolved in 27 (84%) and was improved in the remaining 5. Serum IgG, pepsinogen I, and gastrin levels were significantly decreased after treatment. Of 12 children assessed at six months, 9 remained free of C pylori. Increases or decreases in IgG level indicated clearance or recurrence, respectively, of C pylori.

Prognostic value of serum pepsinogen I in children with peptic ulcer

Serum pepsinogen I (PG I) levels were determined by radioimmunoassay in 23 children with peptic ulcer disease (PUD) before and after treatment with ranitidine and in 44 children who were being investigated for recurrent abdominal pain. Upper gastrointestinal endoscopy was performed in all. No lesions were detected in controls, while 18 patients showed a duodenal ulcer, 4 had an antral ulcer, and 1 had both. An 8-week course of ranitidine healed PUD in 93.5% of them, while long-term (1-5 years) endoscopic follow-up showed a 41.9% ulcer relapse rate after stopping treatment. Gastric acid secretion after pentagastrin stimulation [maximal acid output (MAO)] was tested in all controls and in 22 PUD patients: While controls had normal MAO values for their age, 65% of patients had a secretion above the normal range. No significant correlation was detected between serum PG I and MAO either in controls or in patients. Mean serum PG I concentrations were not significantly higher in the whole patient group than in controls, but PUD patients who relapsed after discontinuing ranitidine treatment had shown on admission significantly higher PG I levels when compared both with those who did not relapse and with controls. All patients who relapsed, but only 42.8% of those who did not, had a serum PG I concentration above the normal upper limit for a pediatric population (56.7 ng/ml). None of the PUD patients who had serum PG I levels under this limit relapsed. Our results suggest that pretreatment serum PG I levels in children with PUD may predict fairly accurately which will not relapse after attaining ulcer healing by a short-term ranitidine course.