Lack of Response to HBHA in HIV-Infected Patients with Latent Tuberculosis Infection.

Heparin-binding haemagglutinin (HBHA) has been proposed as an immunological biomarker for discriminating active tuberculosis (TB) from latent TB infection (LTBI) and to identify those at higher risk of progressing to active disease. Few data are available in immune-compromised patients, which are those with increased risk of TB reactivation. The aim of this stusy was to evaluate the immune response to HBHA in HIV-infected subjects with LTBI (HIV-LTBI) or active TB (HIV-TB) in comparison with the immune response to additional Mycobacterium tuberculosis (Mtb) or HIV and CMV antigens. The responses are evaluated in relation to TB status and in the LTBI subjects with the progression to active TB within 2 years. Forty-one HIV-infected antiretroviral-naïve subjects were prospectively enrolled: 18 were HIV-TB and 23 HIV-LTBI. Whole blood was in vitro stimulated overnight with several antigens and mitogen. Interferon-γ response in the harvested plasma was evaluated by ELISA. Despite that CD4 cell count was significantly different between HIV-LTBI and HIV-TB, no differences were observed in response to Mtb- or HIV-specific antigens. Differently, low responses to HBHA were observed in both HIV-LTBI and HIV-TB subjects. Importantly, none of the six HIV-LTBI responding to HBHA developed TB, while two of 17 non-HBHA responders developed active disease. HIV-TB-coinfected subjects, regardless of their TB status, showed low responses to HBHA despite maintaining detectable responses to other antigens; moreover, among the HIV-LTBI, the lack of HBHA responses indicated an increased risk to develop active TB. These results, although preliminary, suggest that a positive response to HBHA in HIV-LTBI correlates with Mtb containment.

Mycobacterium tuberculosis DNA detection in soluble fraction of urine from pulmonary tuberculosis patients.

SETTING: A tertiary care and research institution in Italy. BACKGROUND: Small DNA fragments from cells dying throughout the body have been detected in urine (transrenal DNA [Tr-DNA]). OBJECTIVE: To test the hypothesis that Mycobacterium tuberculosis Tr-DNA could be detected in the urine of pulmonary tuberculosis (TB) patients. DESIGN: We studied 43 patients with culture-confirmed pulmonary TB with no evidence of extra-pulmonary involvement, 10 patients with pulmonary diseases other than TB and 13 healthy controls. DNA was extracted from urine and analysed by semi-nested polymerase chain reaction (PCR). RESULTS: M. tuberculosis-specific sequences were found in the urine of 34 of 43 (79%) TB patients studied, whereas all controls were negative. The transrenal nature of M. tuberculosis DNA was demonstrated by two lines of evidence: first, separate analysis of supernatants and sediments from eight of the study patients found seven positive supernatants but only two matched positive sediments. Second, M. tuberculosis-specific sequences were amplified by semi-nested PCR with primers designed for short but not large amplicons. CONCLUSION: Small M. tuberculosis DNA fragments may be detected in the urine of a significant proportion of patients with pulmonary TB. If these observations are confirmed by larger studies, Tr-DNA technology could represent a new approach for detecting pulmonary M. tuberculosis infection.

Diagnostic imaging of hepatic tuberculosis: case series.

BACKGROUND: Hepatic tuberculosis (TB) shows non-specific symptoms, and liver imaging may provide diagnostic clues. Here we describe a series of patients with hepatic TB showing characteristic radiological findings. METHODS: Single-centre retrospective evaluation of patients with hepatic TB diagnosed over a period of 16 years who underwent ultrasound, computed tomography (CT) and/or magnetic resonance imaging (MRI). Hepatic lesions were classified as miliary, nodular, serohepatic or cholangitis. RESULTS: Of 14 patients with hepatic TB, five were co-infected with the human immunodeficiency virus. All patients had additional extrahepatic TB localisations. An interferon-gamma release assay was performed in 11/14 patients, ultrasound and CT were available for all patients and MRI for four. Observed patterns were miliary (n = 6) with multiple nodules < 2 cm; nodular (n = 5), characterised by a variable number of nodules (2-7 cm); and serohepatic (n = 3), with multiple nodular subcapsular lesions with a thin, smooth wall. Shared findings were hypoechoic lesions on ultrasound, hypodense lesions with ring enhancement on CT, while MRI lesions were hypointense on T1- and hyperintense on T2-weighted images. CONCLUSIONS: Ultrasound, CT and MRI can independently contribute to detection of hepatic TB. While a miliary pattern or calcifications are characteristic, no pattern is completely pathognomonic and the diagnosis depends on microbiological evidence. Particularly in risk groups, characteristic radiological findings may prompt targeted diagnostic work-up.

Analytical evaluation of QuantiFERON- Plus and QuantiFERON- Gold In-tube assays in subjects with or without tuberculosis.

The QuantiFERON-TB Gold Plus (QFT-Plus) represents the new QuantiFERON-TB Gold In-tube (QFT-GIT) to identify latent tuberculosis infection (LTBI). The main differences is the addition of a new tube containing shorter peptides stimulating CD8 T-cells. Aim of this study is to evaluate the accuracy of QFT-Plus compared with QFT-GIT in a cross sectional study of individuals with or without tuberculosis (TB). We enrolled 179 participants: 19 healthy donors, 58 LTBI, 33 cured TB and 69 active TB. QFT-Plus and QFT-GIT were performed. The two tests showed a substantial agreement. Moreover we found a similar sensitivity in active TB and same specificity in healthy donors. A higher proportion of the LTBI subjects responded to both TB1 and TB2 compared to those with active TB (97% vs 81%). Moreover, a selective response to TB2 was associated with active TB (9%) and with a severe TB disease, suggesting that TB2 stimulation induces a CD8 T-cell response in absence of a CD4-response. In conclusion, QFT-Plus and QFT-GIT assays showed a substantial agreement and similar accuracy for active TB detection. Interestingly, a higher proportion of the LTBI subjects responded concomitantly to TB1 and TB2 compared to those with active TB, whereas a selective TB2 response associated with active TB.

Blood and urine inducible protein 10 as potential markers of disease activity.

SETTING: Blood interferon-γ inducible protein 10 (IP-10) has been proposed as a biomarker of disease activity for both tuberculosis (TB) and human immunodeficiency virus (HIV) infection. Urine IP-10 has been detected in adults with active TB, and its level decreases after successful anti-tuberculosis treatment. OBJECTIVE: To evaluate blood and urine IP-10 as biomarker of disease activity. DESIGN: Patients with HIV-TB and active TB were enrolled. Individuals with HIV infection only and healthy donors were included as controls. Blood and urine IP-10 levels were measured using an enzyme-linked immunosorbent assay. RESULTS: Of 39 active TB patients enrolled, 24 were HIV-infected and 15 were HIV-uninfected. Of 87 control subjects without active TB, 54 were HIV-infected and 33 were HIV-uninfected. IP-10 analysis was performed in patients with concomitant blood and urine sample collection. Blood IP-10 was associated with active TB, regardless of HIV infection status; urine IP-10 levels were increased in active TB patients, although the difference was significant in HIV-infected individuals only. Finally, in HIV-infected patients, both blood and urine IP-10 levels were inversely correlated with CD4 T-cell counts. CONCLUSION: These findings suggest that IP-10 could be used as a biomarker for disease activity (inflammation).

Sporadic hepatitis C virus infection: a case-control study of transmission routes in a selected hospital sample of the general population in Italy.

A case-control study was performed on 9,175 Italian adult outpatients in 5 hospitals in Rome. The study was carried out to clarify the role of some less investigated risk factors (RF) in the spread of hepatitis C virus (HCV) infection. All subjects were contacted by interviewers, who completed a questionnaire. Their sera were stored and subsequently tested for both HCV and hepatitis B virus core (HBc) antibodies. 365 subjects, positive for anti-HCV and anti-HBc-negative, and who had denied intravenous drug use (IDU) (cases) were compared with an equal number of suitable random controls negative for anti-HCV and anti-HBc. Gender, age and region of birth and residence were matched. The prevalence of 13 RFs were statistically compared by univariate and multivariate analysis. A positive anti-HCV test was significantly associated, by multivariate analysis with intravenous treatments and minor surgical procedures (both before 1975) (p < 0.001), blood transfusions (before 1991) (p < 0.01), diabetes (p < 0.01), and deliveries in hospital (p < 0.05) (both before 1975). After 1975 (1991 for transfusions), all associations lost their significance. Intra-familial (sexual and non sexual), occupational RFs and dental care were not significantly associated with the presence of anti-HCV. We suggest that non-disposable syringes, commonly used until 1975 in Italy for i.v. treatments, have been the major route for HCV transmission in Italy among non-IDU subjects.