Inherited IL-12Rβ1 and TYK2 deficiencies impair both IL-12- and IL-23-dependent IFN-γ immunity and are rare monogenic causes of tuberculosis, each found in about 1/100,000 individuals. We show that homozygosity for the common TYK2 P1104A allele, which is found in about 1/600 Europeans and 1/2,500 other individuals, is much more frequent in patients with tuberculosis than in ethnicity-adjusted controls (p = 8.37×10−8, odds ratio = 89.31 [95%CI: 14.7–1,725]). We also show that the frequency of P1104A in Europeans has decreased significantly, from about 9% to 4.2%, over the last 4,000 years, consistent with purging of this variant by endemic tuberculosis. Moreover, we show that catalytically inactive P1104A impairs cellular responses to IL-23, but not to IFN-α, IL-10, or even IL-12, which, like IL-23, induces IFN-γ via activation of TYK2 and JAK2. Finally, we show that catalytically competent TYK2 is critical for IL-23 but not IL-12 responses, whereas catalytically competent JAK2 is redundant for both. Homozygosity for the P1104A missense variant of TYK2 selectively disrupts the induction of IFN-γ by IL-23 and is a common monogenic etiology of tuberculosis.

Although epidemiological evidence suggests a human genetic basis of pulmonary tuberculosis (PTB) susceptibility, the identification of specific genes and alleles influencing PTB risk has proven to be difficult. Previous genome-wide association (GWA) studies have identified only three novel loci with modest effect sizes in sub-Saharan African and Russian populations. We performed a GWA study of 550,352 autosomal SNPs in a family-based discovery Moroccan sample (on the full population and on the subset with PTB diagnosis at <25 years), which identified 143 SNPs with p < 1 × 10−4. The replication study in an independent case/control sample identified four SNPs displaying a p < 0.01 implicating the same risk allele. In the combined sample including 556 PTB subjects and 650 controls these four SNPs showed suggestive association (2 × 10−6 < p < 4 × 10−5): rs358793 and rs17590261 were intergenic, while rs6786408 and rs916943 were located in introns of FOXP1 and AGMO, respectively. Both genes are involved in the function of macrophages, which are the site of latency and reactivation of Mycobacterium tuberculosis. The most significant finding (p = 2 × 10−6) was obtained for the AGMO SNP in an early (<25 years) age-at-onset subset, confirming the importance of considering age-at-onset to decipher the genetic basis of PTB. Although only suggestive, these findings highlight several avenues for future research in the human genetics of PTB.

Increased prevalence of latent tuberculosis infection (LTBI) has been observed among high-risk populations such as healthcare workers (HCWs). The results may depend on the method of LTBI assessment, interferon-gamma release assay (IGRA) and/or tuberculin skin test (TST). Here, we investigated the prevalence and risk factors for LTBI assessed by both IGRAs and TST in HCWs living in Morocco, a country with intermediate tuberculosis (TB) endemicity and high BCG vaccination coverage. HCWs were recruited in two Moroccan hospitals, Rabat and Meknes. All the participants underwent testing for LTBI by both IGRA (QuantiFERON-TB Gold In-Tube, QFT-GIT) and TST. Different combinations of IGRA and TST results defined the LTBI status. Risk factors associated with LTBI were investigated using a mixed-effect logistic regression model. The prevalence of LTBI among 631 HCWs (age range 18–60 years) varied from 40.7% (95%CI 36.9–44.5%) with QFT-GIT to 52% (95%CI 48.2–56.0%) with TST using a 10 mm cut-off. The highest agreement between QFT-GIT and TST (κ = 0.50; 95%CI 0.43–0.56) was observed with the 10 mm cut-off for a positive TST. For a definition of LTBI status using a double positive result for both QFT-GIT and TST, significant associations were found with the following risk factors: being male (OR = 2.21; 95%CI 1.40–3.49; p = 0.0007), belonging to age groups 35–44 years (OR = 2.43; 95%CI 1.45–4.06; p = 0.0007) and even more 45–60 years (OR = 4.81; 95%CI 2.72–8.52; p = 7.10 −8 ), having a family history of TB (OR = 6.62; 95%CI 2.59–16.94; p = 8.10 −5 ), and working at a pulmonology unit (OR = 3.64; 95%CI 1.44–9.23; p = 0.006). Smoking was associated with LTBI status when defined by a positive QFT-GIT result (OR = 1.89; 95%CI 1.12–3.21; p = 0.02). A high prevalence of LTBI was observed among HCWs in two Moroccan hospitals. Male gender, increased age, family history of TB, and working at a pulmonology unit were consistent risk factors associated with LTBI.

Les objectifs de cette étude étaient d'analyser les aspects épidémiologiques, cliniques, para-cliniques, thérapeutiques et évolutifs des patients atteints de la tuberculose neuroméningée. Il s'agit d'une étude rétrospective portant sur 21 patients hospitalisés entre janvier 2002 et décembre 2016 dans le service de neurologie pour une tuberculose neuroméningée. Les femmes étaient légèrement plus représentées que les hommes (SR=0,9), la tranche d´âge entre 20 et 40 ans était prédominante (47,61%). Le délai moyen du diagnostic était de 25 jours. Les symptômes inauguraux étaient principalement des signes généraux (100%). Les signes neurologiques étaient sous forme de céphalées (61,90%), de vomissements (47,61%) et un déficit moteur (33,33%). La ponction lombaire et la tomodensitométrie (TDM) cérébrale ont été réalisées dans 100% des cas. Tous les patients ont bénéficié d´un traitement anti-bacillaire et d´une corticothérapie. L´évolution était favorable dans 61,90% des cas, fatale dans 9,52% des cas et marquée par la persistance de séquelles neurologiques dans 28,57% des cas. La tuberculose neuro-méningée est une pathologie extrêmement polymorphe dans sa présentation clinique et radiologique. L´évolution est le plus souvent favorable si le diagnostic et la prise en charge sont précoces.