Association study of genes controlling IL-12-dependent IFN-γ immunity: STAT4 alleles increase risk of pulmonary tuberculosis in Morocco.

BACKGROUND: Only a minority of individuals infected with Mycobacterium tuberculosis develop clinical tuberculosis. Genetic epidemiological evidence suggests that pulmonary tuberculosis has a strong human genetic component. Previous genetic findings in Mendelian predisposition to more severe mycobacterial infections, including by M. tuberculosis, underlined the importance of the interleukin 12 (IL-12)/interferon γ (IFN-γ) circuit in antimycobacterial immunity. METHODS: We conducted an association study in Morocco between pulmonary tuberculosis and a panel of single-nucleotide polymorphisms (SNPs) covering 14 core IL-12/IFN-γ circuit genes. The analyses were performed in a discovery family-based sample followed by replication in a case-control population. RESULTS: Out of 228 SNPs tested in the family-based sample, 6 STAT4 SNPs were associated with pulmonary tuberculosis (P = .0013-.01). We replicated the same direction of association for 1 cluster of 3 SNPs encompassing the promoter region of STAT4. In the combined sample, the association was stronger among younger subjects (pulmonary tuberculosis onset <25 years) with an odds ratio of developing pulmonary tuberculosis at rs897200 for GG vs AG/AA subjects of 1.47 (1.06-2.04). Previous functional experiments showed that the G allele of rs897200 was associated with lower STAT4 expression. CONCLUSIONS: Our present findings in a Moroccan population support an association of pulmonary tuberculosis with STAT4 promoter-region polymorphisms that may impact STAT4 expression.

Assessment of the Association of Chlamydia e pneumoniae Infection with Lung Cancer in a Moroccan Patients' Cohort.

BACKGROUND: Chlamydia pneumoniae (C. pneumoniae) is a respiratory pathogen associated with chronic inflammatory and its detection in human lung cancer suggests its involvement in cancerogenesis. Our study aimed to evaluate the association between C. pneumoniae  infection and Lung Cancer disease in Moroccans patients and control cohorts, through a molecular investigation. METHODS: The study comprised 42 lung cancer patients and 43 healthy controls. All participants provided demographics, Clinical, and Toxic behaviors datas, and a peripheral blood sample for testing, a Nested Polymerase Chain Reaction (PCR) was performed for C. pneumoniae Deoxyribonucleic acid (DNA) detection. Statistical analysis was performed using IBM®SPSS®software. RESULTS: Positive Nested PCR results for cases and controls were respectively 33.3% and 4.7%, there by  significant difference between cases and controls   infection was identified (p <0.05). Data analysis also showed that tobacco could act synergically with C. pneumoniae infection as a risk factor of lung cancer. In fact a significant difference between patients and controls was shown for tobacco and alcohol use (p < 0.05). CONCLUSION: C. pneumoniae infection is potentially associated with primary Lung cancer in the Moroccan population and has combined effects with Tabaco consumption.

Right Intraventricular Metastasis of Lung Squamous Cell Carcinoma Detected on 18F-Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography.

Cardiac metastasis from lung cancer is rare. They are clinically silent and often diagnosed only postmortem. Cardiac magnetic resonance imaging (MRI) provides interesting information about the tissue characterization and vascularization of the tumor. The 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET/CT) shows hypermetabolism in the cardiac metastasis. We present a case of a 74-year-old male, diagnosed with squamous cell carcinoma of the lung, who underwent cardiac MRI which showed a right intracavitary mass. We share interesting images, detected on 18F-FDG PET/CT, of cardiac metastasis.

[IManagement of patients with relapsed primary naso-sinusal tuberculosis]. / Gestion de la rechute d'une tuberculose naso-sinusienne primaire.

Primary naso-sinusal tuberculosis (TB) is a relatively rare or exceptional disorder characterized by polymorphic or non-specific clinical manifestation. Diagnosis is based on anatomo-pathological examination and mycobacteriology test of biopsy specimen. Predictor of good outcome is early conventional anti-tuberculous antibiotic therapy. However, our study reports recurrence at this rare site in an immunocompetent patient despite early suitable TB treatment and good adherence with therapy. Relapse was correlated with underdosing of rifampicin. This study highlights the diagnostic, etiological and therapeutic management of this relapse. Our experience could help clinicians to better manage this uncommon condition.

Typical presentation of pulmonary lepidic adenocarcinoma: a rare case report.

Bronchioloalveolar carcinoma (BAC) is a rare subtype of adenocarcinoma of lung with distinct features and distinctive characteristics. It accounts approximately for 4% of lung cancers. In the following study we report a rare observation of a 50 years old female with a clinical, radiological and histological presentation, which is typical of an invasive mucinous lepidic adenocarcinoma formerly named BAC.

Prevalence and risk factors for latent tuberculosis infection among healthcare workers in Morocco.

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.

Tuberculosis and impaired IL-23-dependent IFN-γ immunity in humans homozygous for a common TYK2 missense variant.

Inherited IL-12Rß1 and TYK2 deficiencies impair both IL-12- and IL-23-dependent IFN-γ immunity and are rare monogenic causes of tuberculosis, each found in less than 1/600,000 individuals. We show that homozygosity for the common TYK2 P1104A allele, which is found in about 1/600 Europeans and between 1/1000 and 1/10,000 individuals in regions other than East Asia, is more frequent in a cohort of patients with tuberculosis from endemic areas than in ethnicity-adjusted controls (P = 8.37 × 10-8; odds ratio, 89.31; 95% CI, 14.7 to 1725). Moreover, the frequency of P1104A in Europeans has decreased, from about 9% to 4.2%, over the past 4000 years, consistent with purging of this variant by endemic tuberculosis. Surprisingly, we also show that TYK2 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. Moreover, TYK2 P1104A is properly docked on cytokine receptors and can be phosphorylated by the proximal JAK, but lacks catalytic activity. Last, we show that the catalytic activity of TYK2 is essential for IL-23, but not IL-12, responses in cells expressing wild-type JAK2. In contrast, the catalytic activity of JAK2 is redundant for both IL-12 and IL-23 responses, because the catalytically inactive P1057A JAK2, which is also docked and phosphorylated, rescues signaling in cells expressing wild-type TYK2. In conclusion, homozygosity for the catalytically inactive P1104A missense variant of TYK2 selectively disrupts the induction of IFN-γ by IL-23 and is a common monogenic etiology of tuberculosis.

[Swelling of the pectoralis muscle revealing isolated muscular tuberculosis]. / Tuméfaction du muscle pectoral révélant une tuberculose musculaire isolée.

Soft tissue tuberculosis is one of the rare forms of extrapulmonary tuberculosis. Furthermore, isolated muscular tuberculosis is exceptional. We here report the original case of a young immunocompetent patient with isolated muscular tuberculosis involving major pectoralis muscle. The diagnosis was mainly based on histology. The patient was successfully treated with anti bacterial therapy only. This rare case study has been combined with a literature review.

[A rare cause of posterior mediastinal tumors: mediastinal hydatid cyst]. / Une cause rare des tumeurs du médiastin postérieur: le kyste hydatique médiastinal.

Mediastinal hydatid cyst is extremely rare even in endemic areas, representing 0-4% of all hydatid cyst locations. We report the case of a 50-year old patient admitted to our Department with a mass in the left dorsal paraspinal region; chest X-ray showed posterior left basal opacity. Chest CT scan showed posterior mediastinal mass located in the left costovertebral gutter extending from D9 to D11. MRI confirmed the existence of a posterior mediastinal mass with endocanalar extension and spinal cord compression, first evoking cystic schwannoma. These radioclinical data were consistent with a neoplastic origin; a transparietal biopsy was performed which showed a paucicellular specimen composed of translucent eosinophilic material with appearance just barely compatible with hydatid cyst. Hydatic serology was positive. The diagnosis of hydatid cyst was retained and the patient underwent thoracotomy which revealed mediastinal hydatid cyst, confirmed by histologic examination. The postoperative course was uneventful. Mediastinal location of hydatid cyst is very rare and poses a problem in differential diagnosis with other mediastinal tumors.

[Severe pulmonary involvement in hypocomplementemic urticarial vasculitis (HUV)]. / Atteinte pulmonaire sévère au cours de la vascularite hypocomplémentémique urticarienne.

Pulmonary involvement in hypocomplementemic urticarial vasculitis (HUV) or Mac Duffie syndrome is extremely rare with a poor prognosis. We report the case of a 55-year-old female patient treated for HUV over a period of 20 years. The diagnosis was confirmed on the basis of urticarial lesions, ocular inflammation, positive C1q-p test by immunodiffusion, with low rate of C1q. The patient was treated with cycles of cyclophosphamide, corticoids and rituximab as she developed class III dyspnea (NYHA classification ). The clinico-radiological and functional assessment showed thoracic distension and severe obstructive pulmonary disease which found no significant improvement with systemic treatment Aerosol therapy was started and the patient had a marked clinical improvement. Pulmonary involvement in Mac Duffie hypocomplementemic urticarial vasculitis worsens the patient short-term vital prognosis. The knowledge of the different types of pulmonary involvement opens new therapeutic prospects.