Predictors of time to sputum smear conversion in patients with pulmonary tuberculosis under treatment

Sputum acid-fast bacilli smear conversion is a fundamental index of treatment response and reduced infectivity in patients with pulmonary tuberculosis (P-TB). To date, there are no models to predict the time to sputum conversion based on patient characteristics. This study aims to ascertain the time to sputum conversion in patients with smear-positive P-TB under treatment, and the variables associated with time to smear conversion. We retrospectively evaluated the time to sputum smear conversion of 89 patients with smear-positive P-TB undergoing treatment at the S. Orsola-Malpighi University Hospital, Bologna (Italy), a referral centre for the diagnosis of TB. Multivariate Cox regression analysis was performed to document variables independently associated with time to conversion. Median time to sputum smear conversion was 24 days (IQR 12-54); the sputum smear converted within the first 2 months of treatment in 78.7% patients. Multivariate Cox regression analysis showed that older age, high baseline mycobacterial load detected by Xpert MTB/RIF, and severity of lung involvement are predictors of persistent smear positivity. The identification of risk factors delaying smear conversion allowed us to develop predictive models that may greatly facilitate the management of smear-positive patients in terms of the duration of respiratory isolation and treatment.

Perioperative multidisciplinary management of endoscopic transsphenoidal surgery for sellar lesions: practical suggestions from the Padova model

Perioperative management of patients with sellar lesion submitted to endoscopic transsphenoidal neurosurgery (TSS) lacks standardization and therefore it is committed to each center clinical practice. Although neurosurgical procedure remains the same for all sellar lesions, perioperative approach can require different measures depending on the underlying disease. With the aim of standardizing our perioperative procedures and sharing our experience with other centers involved in the management of pituitary disease, we developed a clinical care path for patients with sellar lesions candidate to endoscopic TSS. For the drafting of the following protocol, the national and international guidelines published in the last 5 years have been evaluated and integrated with our center experience accumulated in decades of clinical practice. A steering committee including medical doctors involved in management of patients with pituitary masses at the Padua Hospital reviewed current knowledge on this topic. The committee developed a first draft which was shared with a broader group of medical doctors to reach a preliminary consensus; when it was reached, the clinical care assistance pathway was confirmed, validated, and published in the local web-based health service. We want to present and share our experience with colleagues involved in the perioperative management of pituitary diseases in other centers.

Improvement of Mycobacterium tuberculosis detection by Xpert MTB/RIF Ultra: A head-to-head comparison on Xpert-negative samples

BACKGROUND

The new Xpert MTB/RIF Ultra assay (Ultra, Cepheid, Sunnyvale, USA) is a cartridge-based automated diagnostic test that can simultaneously identify Mycobacterium tuberculosis complex (MTB) and resistance to Rifampicin (RIF). With respect to the previous version Xpert MTB/RIF assay (Xpert), IS6110/IS1081 repetitive elements probes have been added allowing the detection of lower MTB load, defined by the new semi-quantitative category "trace" with indeterminate RIF resistance. The aim of this study was to evaluate performance of the new version Ultra on Xpert-negative, but TB culture-positive clinical samples.

METHODS

The de-identified frozen samples (-20 °C) collected over a 4-year period (February 2014-October 2017), which had previously resulted smear-negative, Xpert-negative but MTB culture-positive, were analyzed with Ultra. The de-frosted samples were loaded into the cartridge using the same process as the previous version, according to manufacturer's instruction.

RESULTS

During the study period 382 MTB culture-positive samples were archived: 314 resulted Xpert-positive and 68 Xpert-negative. Thirty-one of the 68 Xpert-negative samples resulted positive with Ultra, with an overall improvement in MTB detection of 45.6%. Out of 36 Xpert-negative respiratory samples, 18 resulted Ultra-positive with the following semi-quantitative loads: "low"(n = 1), "very low"(n = 11), "trace"(n = 6), with an improvement in MTB detection of 50%. The best performance was achieved on bronchoalveolar lavage specimens (53.8%). Out of 32 Xpert-negative non-respiratory samples, 13 resulted Ultra-positive with the following semi-quantitative loads: "very low"(n = 7), "trace"(n = 6), with an improvement in MTB detection of 40.6%. The best performance was achieved on biopsies (55.6%) and lymph nodes (50%). The new category "trace" detected 12 out of the 31 Ultra-positive MTB samples; in the remaining 19 samples RIF susceptibility was determined with 100% concordance with the phenotypic susceptibility test. The mean time to positivity of samples found negative by Ultra was significantly longer in comparison to positive samples in liquid culture.

CONCLUSIONS

Our results are consistent with the few studies published so far and confirm the better performance of Ultra compared to the previous version in both respiratory and non-respiratory smear-negative samples, with an overall improvement of 45.6%.

Malignant Testicular Germ Cell Tumor in Father and Son: A Case Report

This is the eighteenth case of testicular tumor in a father and son reported in the literature. The father had a seminoma and the son an embryonal carcinoma. The trend favoring more malignant tumors occurring at younger ages in the sons is confirmed by this report.

Galectin-1 is required for the regulatory function of B cells

Galectin-1 (Gal-1) is required for the development of B cells in the bone marrow (BM), however very little is known about the contribution of Gal-1 to the development of B cell regulatory function. Here, we report an important role for Gal-1 in the induction of B cells regulatory function. Mice deficient of Gal-1 (Gal-1^−/−) showed significant loss of Transitional-2 (T2) B cells, previously reported to include IL-10⁺ regulatory B cells. Gal-1^−/− B cells stimulated in vitro via CD40 molecules have impaired IL-10 and Tim-1 expression, the latter reported to be required for IL-10 production in regulatory B cells, and increased TNF-α expression compared to wild type (WT) B cells. Unlike their WT counterparts, T2 and T1 Gal-1^−/− B cells did not suppress TNF-α expression by CD4⁺ T cells activated in vitro with allogenic DCs (allo-DCs), nor were they suppressive in vivo, being unable to delay MHC-class I mismatched skin allograft rejection following adoptive transfer. Moreover, T cells stimulated with allo-DCs show an increase in their survival when co-cultured with Gal-1^−/− T2 and MZ B cells compared to WT T2 and MZ B cells. Collectively, these data suggest that Gal-1 contributes to the induction of B cells regulatory function.

Quantitative Analysis of Gamma Interferon Release Assay Response in Children with Latent and Active Tuberculosis

The use of interferon gamma (IFN-γ) release assays (IGRAs) for the diagnosis of tuberculosis (TB) infection in children is still under debate because of concerns about the immature immune response in children. The aim of this study was to investigate quantitative values of the QuantiFERON-TB Gold In-Tube (QFT-IT) test, a commercially available IGRA, in a large cohort of children screened for TB infection. A retrospective analysis was conducted on samples from 517 children aged 0 to 14 years old at the Pediatric Unit of S. Orsola-Malpighi University Hospital of Bologna (Italy); quantitative responses to QFT-IT stimuli were analyzed according to diagnosis and age. Elevated IFN-γ values in the QFT-IT nil (background) tube were statistically associated with diagnosis of active TB. Quantitative IFN-γ response to Mycobacterium tuberculosis-specific antigens (TB Ag) was not significantly different in children with active TB compared to those with latent TB infection (LTBI), even though the median values were higher in the first group. When children were grouped by age, those less than 5 years old produced significantly higher levels of IFN-γ in response to TB Ag if they had active TB (median 10 IU/ml) than those with LTBI (median 1.96 IU/ml). IFN-γ response to mitogen increased with age. The overall rate of indeterminate results was low (3.9%), and no indeterminate QFT-IT values were observed in active or latent TB patients. In conclusion, quantitative QFT-IT values could provide further information to clinicians to manage TB in children, and these observations could be transferred to the new version of the test, QuantiFERON-TB Gold Plus, which to date lacks data from the pediatric population.