CD4+ T Responses Other Than Th1 Type Are Preferentially Induced by Latency-Associated Antigens in the State of Latent Mycobacterium tuberculosis Infection.

Mycobacterium tuberculosis (M. tuberculosis) produces a diverse range of antigenic proteins in its dormant phase. The cytokine profiles of CD4+ T cell responses, especially subsets other than Th1 type (non-Th1 type), against these latency-associated M. tuberculosis antigens such as α-crystallin (Acr), heparin-binding hemagglutinin (HBHA), and mycobacterial DNA-binding protein 1 (MDP-1) remain elusive in relation to the clinical stage of M. tuberculosis infection. In the present study, peripheral blood mononuclear cells (PBMCs) collected from different stages of M. tuberculosis-infected cases and control PBMCs were stimulated with these antigens and ESAT-6/CFP-10. Cytokine profiles of CD4+ T cells were evaluated by intracellular cytokine staining using multicolor flow cytometry. Our results demonstrate that Th1 cytokine responses were predominant after TB onset independent of the type of antigen stimulation. On the contrary, non-Th1 cytokine responses were preferentially induced by latency-associated M. tuberculosis antigens, specifically IL-10 response against Acr in latent M. tuberculosis infection. From these results, we surmise a shift in the CD4+ T cell response from mixed non-Th1 to Th1 dominant type during TB progression.

[Outbreak of extensively drug-resistant pulmonary tuberculosis in a hemodialysis facility].

We experienced an outbreak of extensively drug-resistant pulmonary tuberculosis (XDR-TB) in a hemodialysis facility. The primary case involved a 51-year-old male hemodialysis patient, with a history of treatment for Mycobacterium tuberculosis infection seven years previously. There was no drug resistance, and the patient completely recovered after undergoing treatment with isoniazid (INH), rifampicin (RFP) and ethambutol (EB). He was admitted to another hospital due to a recurrence of pulmonary tuberculosis in June 2006. At first, he was treated with HRS [INH, RFP and streptomycin (SM)]; however, the drug regimen was changed to INH, EB, levofloxacin (LVFX) and kanamycin (KM) in August following the results of a drug susceptibility test. Although the patient was receiving outpatient tuberculous therapy, he was readmitted in June 2007 due to relapse and conversion of a sputum culture to positive status. Additionally, the XDR-TB organism was identified. Following these events, five staff members of the hemodialysis facility and a member of the patient's family were diagnosed with XDR-TB infection. The staffs who were infected with XDR-TB had worked in the same dialysis room, drug resistance was found in all cases and drug resistant gene mutations were found in three cases; therefore, we considered this to be an outbreak. As XDR-TB infection was suspected in all cases, no patients took drugs to treat latent tuberculosis infection (LTBI). Regarding the causes of the outbreak, the first is the delay of four months in making a diagnosis of re-exacerbation of tuberculosis. Second, in Case 2, the patient developed laryngeal and tracheobronchial tuberculosis after first being diagnosed with asthma, and the tuberculosis diagnosis was delayed. Third, the sputum smear of Case 2 was strongly positive. There is only one previously reported outbreak of XDR-TB in Japan; therefore, we consider this outbreak to be educational.

[Clinical investigation of multidrug-resistant tuberculosis --investigation of inpatients in the Kyushu region between 2004 and 2009].

OBJECTIVE: To conduct a clinical investigation of patients with multidrug-resistant (MDR) tuberculosis who received either drug therapy alone or drug therapy in combination with surgery. SUBJECTS AND METHODS: A total of 56 patients with MDR tuberculosis who were admitted to hospitals of the National Hospital Organization in the Kyushu region between January 2004 and September 2009 and received drug therapy either alone or in combination with surgery were investigated. RESULTS: As surgery could not be performed in patients with advanced age or with bilateral extensive lesions, only 12 patients (21%) were able to undergo surgery. Initial drug resistance was seen in 10 patients (23%) in the drug therapy group and four patients (33%) in the combination therapy group. Underlying diseases included diabetes in 15 patients (34%) in the drug therapy group and in 6 patients (50%) in the combination therapy group. Negative conversion of the sputum culture result was observed in 43% in the drug therapy group and in 75% in the combination therapy group. The death within three years was seen in 20 patients (45%) in the drug therapy group and 1 patient (8%) in the combination therapy group. In the drug therapy group there were more cases with resistance to 5 drugs, resistance to levofloxacin (LVFX), and/or kanamycin (KM) in those who died of tuberculosis than in non-tuberculous death cases. CONCLUSION: Resistance to 5 drugs, resistance to LVFX, and resistance to KM were contributing factors of tuberculous death. Patient's operability was one of the factors associated with a good prognosis.