Prostaglandins (PG) are potent mediators of intercellular communication, and PGE2 at high concentration is immunosuppressive for T-cell-mediated immunity. We studied the kinetics of PGE2 production and the expression of the enzymes related to its synthesis during the course of experimental pulmonary tuberculosis. Secondly, we analysed the pathological and immunological changes produced by the pharmacological suppression of PG production. In BALB/c mice infected via the trachea with Mycobacterium tuberculosis H37Rv there is an initial phase of partial resistance, dominated by type 1 cytokines plus tumour necrosis factor-alpha (TNF-alpha) and expression of the inducible form of nitric oxide synthase (iNOS), followed by a phase of progressive disease. During the early phase of the infection some activated macrophages located in the alveolar-capillary interstitium and in granulomas showed strong PGE2 immunostaining. However, PGE2 concentrations were relatively low and stable. Animals in this early phase of infection were treated with niflumic acid, a potent and specific blocker of cyclo-oxygenase 2, the rate-limiting enzyme of PG production. In comparison with control animals, the suppression of PG synthesis produced higher inflammation and expression of TNF-alpha, interleukin-1alpha and interferon-gamma (IFN-gamma), but almost complete disappearance of iNOS expression, which coexisted with a significant increment of bacterial load. The late progressive phase in this experimental model is characterized by progressive pneumonia, small granulomas and diminished expression of IFN-gamma, TNF-alpha and iNOS in coexistence with high expression of IL-4. Strong PGE2 immunostaining was seen in foamy macrophages localized in the pneumonic areas, and the PGE2 concentration was four-fold higher in this late phase of infection than during the early phase. When PG production was suppressed in animals suffering advanced phase infection, a significant reduction of pneumonia and bacillus load with striking increment of granuloma size was seen, and the expression of IFN-gamma, TNF-alpha and iNOS was also improved. These findings demonstrate a significant participation of PGE2 in the pathogenesis of pulmonary tuberculosis, showing that during the early phase of the infection there are low PGE2 concentrations which contribute to iNOS expression permitting the temporal control of bacillus growth, while the high PGE2 concentrations during the late phase of the disease contribute to down-regulate cell-mediated immunity, permitting disease progression.

IntroductionHuman papillomavirus (HPV) testing is replacing cytology in primary screening. Its limited specificity demands using a second (triage) test to better identify women at high-risk of cervical disease. Cytology represents the immediate triage but its low sensitivity might hamper HPV testing sensitivity, particularly in low-income and middle-income countries (LMICs), where cytology performance has been suboptimal. The ESTAMPA (EStudio multicéntrico de TAMizaje y triaje de cáncer de cuello uterino con pruebas del virus del PApiloma humano; Spanish acronym) study will: (1) evaluate the performance of different triage techniques to detect cervical precancer and (2) inform on how to implement HPV-based screening programmes in LMIC.Methods and analysisWomen aged 30–64 years are screened with HPV testing and Pap across 12 study centres in Latin America. Screened positives have colposcopy with biopsy and treatment of lesions. Women with no evident disease are recalled 18 months later for another HPV test; those HPV-positive undergo colposcopy with biopsy and treatment as needed. Biological specimens are collected in different visits for triage testing, which is not used for clinical management. The study outcome is histological high-grade squamous intraepithelial or worse lesions (HSIL+) under the lower anogenital squamous terminology. About 50 000 women will be screened and 500 HSIL+ cases detected (at initial and 18 months screening). Performance measures (sensitivity, specificity and predictive values) of triage techniques to detect HSIL+ will be estimated and compared with adjustment by age and study centre.Ethics and disseminationThe study protocol has been approved by the Ethics Committee of the International Agency for Research on Cancer (IARC), of the Pan American Health Organisation (PAHO) and by those in each participating centre. A Data and Safety Monitoring Board (DSMB) has been established to monitor progress of the study, assure participant safety, advice on scientific conduct and analysis and suggest protocol improvements. Study findings will be published in peer-reviewed journals and presented at scientific meetings.Trial registration numberNCT01881659

Background Cervical cancer (CC) is one of the leading causes of cancer mortality among women from Paraguay, with high incidence and mortality rates (31.2 and 16 per 100 000 women, respectively). Although the risk factors associated with high-risk human papillomavirus (hrHPV) infection and preneoplastic cervical lesions are widely studied, population-based characteristics of particular settings may influence the feasibility of HPV-based CC screening implementation. This study aimed to explore factors associated with hrHPV infection and high-grade cervical neoplasia in hrHPV-positive (hrHPV+) women from Paraguay. Methods A total of 5677 women aged 30–64 years from the Central Department of Paraguay were screened with HPV test (Hybrid Capture 2) and Pap smear. Sociodemographic and risk factor interviews were conducted. hrHPV+ women were referred to colposcopy and women with an abnormal colposcopy had a biopsy taken. The outcomes recorded were the hrHPV status and the presence of high-grade cervical intraepithelial neoplasia or worse (CIN2+) among hrHPV+ women. Associations were investigated using multivariate logistic regressions. Results hrHPV prevalence was 13.8% (95%CI 13.0–14.8). This value decreased with the age of women (p-trend<0.001) and increased with the lifetime number of sexual partners (p-trend<0.001) and number of previous female partners of their current male partner if women had had one lifetime sexual partner (p-trend<0.001), increasing from 3.06 (95%CI 0.073–20.9) if partners had had one previous female partner to 9.19 (95%CI 2.36–61.1) if they had had eight or more. In hrHPV+ women, CIN2+ prevalence was 10.7% (95%CI 8.58–13.2) and increased with time since the last Pap smear (p-trend<0.001) and with the increasing number of pregnancies (p-trend = 0.05). Conclusion In these settings, the sexual behavior of women and their male partners is associated with hrHPV infection. In hrHPV+ women, underscreening practices and multiple pregnancies are associated with CIN2+. This knowledge can contribute to public health policies for CC prevention and control in Paraguay.

HPV testing is a better alternative for cervical cancer screening, but additional procedures are required for triage of HPV positive women. HPV encoded oncoproteins E6 and E7, as the main effectors of HPV carcinogenicity represent promising triage alternatives. To evaluate performance of the test, we included 155 women from a screening study and 59 from the same referral population attending colposcopy and with precancerous lesions. All were HPV‐tested with HC2 and genotyped with LiPA, and cervical swabs were tested for HPV16/18 E6 oncoproteins. Histologic specimens were reviewed and adjudicated using p16 immunohistochemistry and 55 women had confirmed histologic HSIL, 31 (56.3%) associated with HPV 16/18, 23 with other HPV types and one HPV negative. Sensitivity and specificity were estimated with histologic HSIL/cancer as gold standard. E6 oncoprotein was detectable in all but one HSIL and in all cancers where HPV16/18 DNA was detected, but in none of the cases associated with other HPV types or HPV negatives. Among the few HPV16/18 DNA positive subjects initially without HSIL (n = 4) who were E6 oncoprotein positive, precancer was detected during follow‐up in 2 out of 3 with available information. Estimated sensitivity for HPV16/18‐related HSIL+ was 96.8% (95%CI = 83.8–99.8) and for all HSIL+ regardless of HPV type it was 56.4% (95%CI = 43.3–68.6). Specificity was 97.5% (95%CI = 93.7–99.0). E6 oncoprotein proved as a highly sensitive and specific marker for detection of HPV16/18‐related HSIL lesions in this Honduran population with limited previous screening and may be useful as a triage method in screening programs, particularly in low income countries.

The insulin-like growth factor (IGF) axis plays an essential role in the development of the mammary gland. High circulating levels of IGF-I and of its major binding protein IGFBP3 have been related with increased mammographic density in Caucasian premenopausal women. Some common single nucleotide polymorphisms (SNPs) in genes of the IGF pathway have also been suggested to play a role in mammographic density. We conducted a cross-sectional study nested within the large Mexican ESMaestras cohort, to investigate the relation between circulating levels of IGF-I, IGFBP-3, the IGF-I/IGFBP-3 ratio, five common SNPs in the IGF-1, IGFBP-3 and IGF-1R genes, and mammographic density in 593 premenopausal Mexican women. Mean age at mammogram was 43.1 (standard deviation–SD=3.7) years, and average body mass index (BMI) at recruitment was 28.5 kg/m2. Mean percent mammographic density was 36.5% (SD: 17.1), with mean dense tissue area of 48.3 (SD: 33.3) cm2. Mean IGF-I and IGFBP-3 concentrations were 15.33 (SD: 5.52) nmol/l and 114.96 (SD: 21.34) nmol/l, respectively. No significant associations were seen between percent density and biomarker concentrations but women with higher IGF-I and IGF-I/IGFBP-3 concentrations had lower absolute dense (ptrend =0.03 and 0.09, respectively) and non-dense tissue areas (ptrend <0.001 for both parameters). However, these associations were null after adjustment by BMI. SNPs in specific genes were associated with circulating levels of growth factors, but not with mammographic density features. These results do not support the hypothesis of a strong association between circulating levels of growth hormones and mammographic density in Mexican premenopausal women.