Inherited IL-12p40 deficiency: genetic, immunologic, and clinical features of 49 patients from 30 kindreds.

Autosomal recessive interleukin (IL)-12 p40 (IL-12p40) deficiency is a rare genetic etiology of mendelian susceptibility to mycobacterial disease (MSMD). We report the genetic, immunologic, and clinical features of 49 patients from 30 kindreds originating from 5 countries (India, Iran, Pakistan, Saudi Arabia, and Tunisia). There are only 9 different mutant alleles of the IL12B gene: 2 small insertions, 3 small deletions, 2 splice site mutations, and 1 large deletion, each causing a frameshift and leading to a premature stop codon, and 1 nonsense mutation. Four of these 9 variants are recurrent, affecting 25 of the 30 reported kindreds, due to founder effects in specific countries. All patients are homozygous and display complete IL-12p40 deficiency. As a result, the patients lack detectable IL-12p70 and IL-12p40 and have low levels of interferon gamma (IFN-γ). The clinical features are characterized by childhood onset of bacille Calmette-Guérin (attenuated Mycobacterium bovis strain) (BCG) and Salmonella infections, with recurrences of salmonellosis (36.4%) more common than recurrences of mycobacterial disease (25%). BCG vaccination led to BCG disease in 40 of the 41 patients vaccinated (97.5%). Multiple mycobacterial infections were rare, observed in only 3 patients, whereas the association of salmonellosis and mycobacteriosis was observed in 9 patients. A few other infections were diagnosed, including chronic mucocutaneous candidiasis (n = 3), nocardiosis (n = 2), and klebsiellosis (n = 1). IL-12p40 deficiency has a high but incomplete clinical penetrance, with 33.3% of genetically affected relatives of index cases showing no symptoms. However, the prognosis is poor, with mortality rates of up to 28.6%. Overall, the clinical phenotype of IL-12p40 deficiency closely resembles that of interleukin 12 receptor ß1 (IL-12Rß1) deficiency. In conclusion, IL-12p40 deficiency is more common than initially thought and should be considered worldwide in patients with MSMD and other intramacrophagic infectious diseases, salmonellosis in particular.

Food incentives improve adherence to tuberculosis drug treatment among homeless patients in Russia.

The aim of the study was to evaluate the impact of food incentives on adherence to tuberculosis (TB) drug treatment among homeless patients with TB. Food packages were thus given as a part of directly observed therapy to 142 homeless patients with TB at a dispensary in Saint Petersburg, Russian Federation. In addition, a social worker provided the patients with information and legal assistance, for example help with internal passports. Among the 142 patients, 66 were included in the study at the dispensary during their entire treatment period, while 76 patients were included in the study during shorter periods mainly because of transfer to inpatient care. In the first group, 59% of the patients continued the TB drug treatment without interruption in contrast to 31% in a control group. In the second group, that is those studied during shorter periods, 95% continued the TB drug treatment without interruption while attached to the dispensary. Food was introduced in the TB programme of the City of St. Petersburg as a consequence of this study. In conclusion, it can be stated that the food incentive had a strong positive impact on the adherence to TB drug treatment among these socially marginalized patients. The social support contributed in all probability also to the positive results.

IL-12Rß1 deficiency in two of fifty children with severe tuberculosis from Iran, Morocco, and Turkey.

BACKGROUND AND OBJECTIVES: In the last decade, autosomal recessive IL-12Rß1 deficiency has been diagnosed in four children with severe tuberculosis from three unrelated families from Morocco, Spain, and Turkey, providing proof-of-principle that tuberculosis in otherwise healthy children may result from single-gene inborn errors of immunity. We aimed to estimate the fraction of children developing severe tuberculosis due to IL-12Rß1 deficiency in areas endemic for tuberculosis and where parental consanguinity is common. METHODS AND PRINCIPAL FINDINGS: We searched for IL12RB1 mutations in a series of 50 children from Iran, Morocco, and Turkey. All children had established severe pulmonary and/or disseminated tuberculosis requiring hospitalization and were otherwise normally resistant to weakly virulent BCG vaccines and environmental mycobacteria. In one child from Iran and another from Morocco, homozygosity for loss-of-function IL12RB1 alleles was documented, resulting in complete IL-12Rß1 deficiency. Despite the small sample studied, our findings suggest that IL-12Rß1 deficiency is not a very rare cause of pediatric tuberculosis in these countries, where it should be considered in selected children with severe disease. SIGNIFICANCE: This finding may have important medical implications, as recombinant IFN-γ is an effective treatment for mycobacterial infections in IL-12Rß1-deficient patients. It also provides additional support for the view that severe tuberculosis in childhood may result from a collection of single-gene inborn errors of immunity.

Revisiting human IL-12Rß1 deficiency: a survey of 141 patients from 30 countries.

Interleukin-12 receptor ß1 (IL-12Rß1) deficiency is the most common form of Mendelian susceptibility to mycobacterial disease (MSMD). We undertook an international survey of 141 patients from 102 kindreds in 30 countries. Among 102 probands, the first infection occurred at a mean age of 2.4 years. In 78 patients, this infection was caused by Bacille Calmette-Guérin (BCG; n = 65), environmental mycobacteria (EM; also known as atypical or nontuberculous mycobacteria) (n = 9) or Mycobacterium tuberculosis (n = 4). Twenty-two of the remaining 24 probands initially presented with nontyphoidal, extraintestinal salmonellosis. Twenty of the 29 genetically affected sibs displayed clinical signs (69%); however 8 remained asymptomatic (27%). Nine nongenotyped sibs with symptoms died. Recurrent BCG infection was diagnosed in 15 cases, recurrent EM in 3 cases, recurrent salmonellosis in 22 patients. Ninety of the 132 symptomatic patients had infections with a single microorganism. Multiple infections were diagnosed in 40 cases, with combined mycobacteriosis and salmonellosis in 36 individuals. BCG disease strongly protected against subsequent EM disease (p = 0.00008). Various other infectious diseases occurred, albeit each rarely, yet candidiasis was reported in 33 of the patients (23%). Ninety-nine patients (70%) survived, with a mean age at last follow-up visit of 12.7 years ± 9.8 years (range, 0.5-46.4 yr). IL-12Rß1 deficiency is characterized by childhood-onset mycobacteriosis and salmonellosis, rare recurrences of mycobacterial disease, and more frequent recurrence of salmonellosis. The condition has higher clinical penetrance, broader susceptibility to infections, and less favorable outcome than previously thought.

Clinical disease caused by Klebsiella in 2 unrelated patients with interleukin 12 receptor beta1 deficiency.

Patients with interleukin 12 (IL-12)p40 or IL-12 receptor ß1 (IL12Rß1) deficiencies are prone to develop infections caused by mycobacteria and salmonella; other infections have only been rarely observed. In this report we describe 2 unrelated patients with complete autosomal recessive IL12Rß1 deficiency who suffered from sepsis attributable to Klebsiella pneumoniae. A Mexican boy suffered from disseminated bacille Calmette-Guérin disease and infections caused by K pneumoniae and Candida albicans and had a fatal outcome. A Turkish girl living in France suffered from disseminated Nocardia nova infection and K pneumoniae sepsis. Therefore, Klebsiella infections should be considered in patients with IL12Rß1 deficiency. Conversely, IL12Rß1 deficiency should be considered in patients with unexplained klebsiellosis.

Mutations in STAT3 and IL12RB1 impair the development of human IL-17-producing T cells.

The cytokines controlling the development of human interleukin (IL) 17--producing T helper cells in vitro have been difficult to identify. We addressed the question of the development of human IL-17--producing T helper cells in vivo by quantifying the production and secretion of IL-17 by fresh T cells ex vivo, and by T cell blasts expanded in vitro from patients with particular genetic traits affecting transforming growth factor (TGF) beta, IL-1, IL-6, or IL-23 responses. Activating mutations in TGFB1, TGFBR1, and TGFBR2 (Camurati-Engelmann disease and Marfan-like syndromes) and loss-of-function mutations in IRAK4 and MYD88 (Mendelian predisposition to pyogenic bacterial infections) had no detectable impact. In contrast, dominant-negative mutations in STAT3 (autosomal-dominant hyperimmunoglobulin E syndrome) and, to a lesser extent, null mutations in IL12B and IL12RB1 (Mendelian susceptibility to mycobacterial diseases) impaired the development of IL-17--producing T cells. These data suggest that IL-12Rbeta1- and STAT-3--dependent signals play a key role in the differentiation and/or expansion of human IL-17-producing T cell populations in vivo.

Impaired expression of perforin and granulysin in CD8+ T cells at the site of infection in human chronic pulmonary tuberculosis.

Protective immunity in tuberculosis is dependent on the coordinated release of cytolytic effector molecules from effector T cells and the subsequent granule-associated killing of infected target cells. In this study, we investigated the expression of cytolytic (perforin and granzyme A) and antimicrobial (granulysin) molecules at the single-cell level in cryopreserved lung tissue from patients with chronic, progressive tuberculosis disease. Quantification of protein-expressing cells was performed by in situ imaging, while mRNA levels in the infected tissue were analyzed by real-time PCR. Persistent inflammation, including excessive expression of inducible nitric oxide synthase in CD68+ macrophages and significant infiltration of CD3+, CD8+ and CD4+ T cells, was evident in tuberculosis lesions in all patients. However, despite the accumulation of CD3+ T cells, perforin- and granulysin-expressing CD3+ T cells were detected at two- to threefold-lower ratios in the tuberculosis lesions than in distal lung parenchyma and uninfected control lungs, respectively. This was evident at both the protein and mRNA levels. Moreover, perforin- and granulysin-expressing CD8+ T cells were scarce in individual granulomas within the tuberculosis lesions. In contrast, significant up-regulation of granzyme A-expressing CD3+ T cells was evident in the lesions from all patients. Confocal microscopy revealed coexpression of perforin and granulysin, primarily in CD8+ T cells; however, this expression was lower in the tuberculosis lesions. These findings suggest that symptomatic, chronic tuberculosis disease is associated with insufficient up-regulation of perforin and granulysin coexpression in CD8+ T cells at the local site of infection.

Tumor necrosis factor is critical to control tuberculosis infection.

Tumor necrosis factor (TNF) is critical and non-redundant to control Mycobacterium tuberculosis infection and cannot be replaced by other proinflammatory cytokines. Overproduction of TNF may cause immunopathology, while TNF neutralization reactivates latent and chronic, controlled infection, which is relevant for the use of neutralizing TNF therapies in patients with rheumatoid arthritis.

Reactivation of tuberculosis by tumor necrosis factor neutralization.

Tumor necrosis factor (TNF) is required in the control of infection with Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis. TNF is essential and non-redundant for forming microbiocidal granulomas, and cannot be replaced by other members of the TNF family. We established a model of latent Mtb infection in mice, allowing investigation of the reactivation of latent Mtb as observed in patients receiving TNF-neutralizing therapy used in rheumatoid arthritis and Crohn's disease. Antibody neutralization of TNF is able to reactivate clinically silent Mtb infection. Using mutant mice expressing solely membrane, but not soluble TNF, we demonstrated that membrane TNF is sufficient to control acute Mtb infection. Therefore, we hypothesize that TNF-neutralizing therapy, sparing membrane TNF, may have an advantage as compared to complete neutralization. In conclusion, endogenous TNF is critical for the control of tuberculosis infection. Genetic absence or pharmacological neutralization of TNF results in uncontrolled infection, while selective neutralization might retain the desired anti-inflammatory effect but reduce the infectious risk.

Tuberculosis in St. Petersburg and the Baltic Sea region.

Tuberculosis (TB) remains a global public health concern and challenges the national structures for infection control and health care, as well as international institutions, to develop and implement new strategies to control and combat this disease. In our report, we investigated the TB epidemiological situation in St. Petersburg and the countries around the Baltic Sea using national epidemiological statistics and epidemiological reports of international organizations, such as the WHO and Euro-TB. After the disintegration of the Soviet Union, a steep increase in tuberculosis was seen in the Russian Federation, St. Petersburg and the Baltic States, after which it stabilized at levels significantly higher compared to the Nordic countries. Moreover, the epidemiological situation in St. Petersburg and the Baltic States was aggravated by the emergence and spread of TB/HIV coinfection, as well as that of drug-resistant M. tuberculosis, which imposed further difficulties in gaining control of TB. During the studied period, the TB burden in neither St. Petersburg nor Baltic States has had a significant impact on the epidemiology in the low TB burden neighbouring countries around the Baltic Sea.

Detection of human perforin by ELISpot and ELISA: ex vivo identification of virus-specific cells.

The perforin (PFN) protein is essential for the elimination of target cells by cytotoxic T lymphocytes (CTL) and natural killer (NK) cells. The study of cells releasing PFN has been hampered by a lack of sensitive methods. We therefore produced PFN-reactive monoclonal antibodies (mAb) and developed capture enzyme-linked immunosorbent (ELISA) and enzyme-linked immunospot (ELISpot) assays. Three mAbs were generated and shown to react with unique determinants of PFN. All mAbs recognized intracellular PFN in human peripheral blood mononuclear cell (PBMC) as assessed by flow cytometry and immunohistochemistry. Functional PFN capture ELISA and ELISpot assays were developed utilizing two of the mAbs for capture and the third mAb for detection. When examining PFN release by the YT lymphoma cell line, the ELISpot displayed a greater detection sensitivity than the ELISA. Assessment of PFN release by a CTL clone using ELISpot gave results consistent with a parallel (51)Cr-release cytotoxicity assay. Moreover, PFN release by PBMC could be quantified by ELISpot and ELISA after ex vivo stimulation with defined CTL epitopes from common viruses. These novel immunoassays will be valuable for further investigations of the mechanisms underlying granule-mediated apoptosis. In addition, the capture immunoassays could provide tools for studying CTL responses in infectious and tumor diseases as well as for vaccine development.