耐多药空洞肺结核的介入治疗

目的　探讨耐多药空洞肺结核介入治疗的意义。方法 采用 36例临床培养的耐药菌株作耐药结核菌抑制试验、临床对照观察的方法。 1 80例耐多药空洞肺结核住院患者随机分成两组,均用 3DLOZA/1 8DLOZ化疗方案治疗,治疗组 86例配合抗结核药物凝胶介入治疗并完成疗程。结果 提高抗结核药物浓度,可有效控制耐药结核菌生长,而所需浓度远远低于药物凝胶的含药浓度。临床观察治疗组比对照组痰菌阴转率高 (88.4%),痰菌阴转速度也快,空洞闭合率高 (43.0%),空洞闭合速度快,疗效较好。单发空洞、干酪空洞的疗效比多发空洞、纤维空洞的疗效较好。未发现与介入药物凝胶有关的不良反应。结论 经纤支镜引导灌注抗结核药物凝胶,是治疗耐多药空洞肺结核的有效方法,其有净化空洞,促使痰菌转阴,空洞闭合的作用。并且有安全无创,无明显不良反应,并发症少的优点,值得临床推广使用。     

Sparfloxacin in the treatment of drug resistant tuberculosis or intolerance of first line therapy.

Patients with multiresistant tuberculosis (TB) and patients with intolerance of first line antituberculosis drugs present a major treatment problem. Sparfloxacin is highly active against mycobacteria, but the use is restricted by side effects and the contribution to antituberculosis therapy is unclear. A prospective study has therefore been performed to analyse the efficacy and tolerability of sparfloxacin in cases of resistant TB or intolerance of first line therapy. Between April 1993 and April 1999, 30 TB patients (28 with pulmonary TB and two with lymph node TB) were treated with combinations of sparfloxacin and at least two other drugs at the Chest Hospital Heckeshorn, Berlin. Sixteen patients were infected by resistant mycobacteria (one single drug resistance (SDR), one polyresistance, and 14 multidrug resistances (MDR); 14 males (age range 23-53 yrs), 2 females (68-74 yrs)). Twelve patients (11 males, one female, 27-80 yrs) had not tolerated first line antituberculosis drugs. Two additional male patients had continuous proof of Mycobacterium tuberculosis in sputum without resistance during therapy The duration of sparfloxacin therapy during hospitalization ranged 2.5-4 months. Twenty-five patients completed therapy and were cured according to this study's definition. Although sparfloxacin was generally well tolerated, five mild phototoxic reactions and six moderate prolongations of the electrocardiographic QT-interval (30-40 ms compared to baseline < or = 450 ms) were registered without clinical symptoms in the patient group. In summary, sparfloxacin proved an effective and safe alternative antituberculosis drug for complicated tuberculosis.     

Immune reconstitution syndrome in patients treated for HIV and tuberculosis in Rio de Janeiro.

We made a retrospective longitudinal study from January 2000 to January 2003 to examine cases of immune reconstitution syndrome (IRS) and its incidence rate in tuberculosis (TB)-human immunodeficiency virus (HIV) co-infected patients. The incidence rate (IR) was calculated using a Poisson regression. The confidence interval (CI) that was stipulated was 95%. IRS occurred in 10/84 HIV and TB-positive patients; nine of them were on highly active anti-retroviral therapy (HAART) during a mean of 61.7 (+/- 59) days following the introduction of antiretrovirals. Lymph-node enlargement was the sole clinical manifestation. CD4 counts were <100 cells/mm(3)in 50% of the patients, at the time of TB diagnosis. All but two patients were treated with prednisone, and recovered from TB within a mean of 91 days (+/- 30 days). One relapse of TB was observed, but there were no IRS-related deaths. The incidence rate was higher (IR=11.18; CI, 1.41-88.76) in patients that had superficial lymph node enlargement at the moment of TB diagnosis (not associated with TB), extrapulmonary TB (IR=1.97; CI, 0.44-8.79), were antiretroviral naive (IR=1.85; CI, 0.48-7.16), and CD4 counts <100 cells/mm(3) (IR=1.50; CI, 0.40-5.59), although with a wide CI. IRS was frequent in our sample, occurred more frequently in HIV-naive patients with lymph-node enlargement and extrapulmonary TB. No cases of new pulmonary lesions or worsening of pulmonary infiltrates were observed.     

Mycobacterium kansasii: a cause of treatable pulmonary disease associated with advanced human immunodeficiency virus (HIV) infection.

OBJECTIVE: To assess the clinical features and response to therapy of Mycobacterium kansasii infection in patients with human immunodeficiency virus (HIV) infection. DESIGN: We reviewed the records of all patients with M. kansasii and HIV infection treated between January 1985 and June 1990. SETTING: The Johns Hopkins Hospital, Baltimore, Maryland. RESULTS: Nineteen patients with M. kansasii and HIV infection were identified; 14 patients had exclusive pulmonary infection, 3 patients had pulmonary and extrapulmonary infection, and 2 patients had exclusive extrapulmonary infection. At the time of diagnosis of M. kansasii infection, the median CD4+ lymphocyte count was 49 cells/microL (range, 0 to 198 cells/microL), and 16 of 19 patients had a previous diagnosis of the acquired immunodeficiency syndrome (AIDS). All 17 patients with pulmonary infection presented with fever and cough of at least 2 weeks duration. Chest radiographs showed either focal upper lobe infiltrates (n = 8) or diffuse interstitial infiltrates (n = 9); 9 patients also had thin-walled cavitary lesions. Nine patients with pulmonary M. kansasii infection were treated with antituberculosis chemotherapy, with resolution of fever and respiratory symptoms, improvement of radiographic infiltrates, and sputum conversion; 1 patient with M. kansasii osteomyelitis also responded to antituberculosis therapy. Autopsies done on 3 treated patients did not reveal any evidence of M. kansasii infection. Nine patients did not receive any antituberculosis chemotherapy; 2 untreated patients developed progressive cavitary pulmonary disease and died from M. kansasii pneumonia. CONCLUSIONS: Mycobacterium kansasii causes serious and potentially life-threatening pulmonary disease in patients with advanced HIV-related immunosuppression. In contrast to previous reports, our findings indicate that disease produced by M. kansasii in patients with HIV infection is responsive to antituberculosis chemotherapy.     

Errors in the treatment of tuberculosis in Baltimore

BACKGROUND: Incomplete or incorrect antibiotic therapy, especially in the initial phase of antituberculosis (anti-TB) treatment, is a major cause of acquired drug resistance and treatment failure. We determined the extent of errors in anti-TB treatment regimens by way of nonadherence to recommended treatment protocols among patients with TB in Baltimore, MD, a city with declining rates of disease. An error was defined as using too few drugs or the wrong drugs, giving inadequate doses of drugs, or prescribing an inadequate duration of treatment. METHODS: We reviewed the records of all patients with culture-positive, pulmonary TB reported in the city of Baltimore from January 1, 1994, to December 31, 1995. We determined demographic information, initial anti-TB regimen, doses and duration of therapy, history or presence of resistance to anti-TB drugs, injecting-drug or alcohol abuse, HIV status, and whether treatment was given by a private physician or by the Tuberculosis Clinic of the Baltimore City Health Department (BCHD). RESULTS: Of the 110 cases of active pulmonary TB, 17 cases (15.4%) had errors in treatment for control of their current disease. Thirteen of 34 privately treated patients (38%) had some error in their initial anti-TB regimen, compared with 4 of 76 patients (5.2%) treated by the Tuberculosis Clinic of the BCHD (p < 0.0001). Patients were otherwise similar as determined by age, sex, HIV status, drug-resistance characteristics, and injecting-drug use, regardless of whether they had erroneous anti-TB regimens. CONCLUSION: In a low-prevalence area, private physicians make frequent errors in prescribing anti-TB therapy. Additional educational resources for physicians and increased use of expert consultation may contribute to improved TB control.     

Drug-resistant tuberculosis in a southern California hospital. Trends from 1969 to 1984

Resistance to one or more antituberculosis drugs was found in 98 of 281 (35%) patients hospitalized at Harbor-UCLA with culture-positive tuberculosis between 1980 and 1984. Resistance to antituberculosis drugs occurred in 23% of patients who had not been previously treated, whereas previously treated patients had a 59% rate of resistance. The overall rates of drug resistance had not significantly changed from prior studies at this hospital. Drug resistance was also found in patients with extrapulmonary disease, but tended to be less frequent than in patients with pulmonary disease. An analysis of risk factors for drug resistance rates revealed no significant differences between Hispanics, blacks, Caucasians, and Asians. Age was not found to be a significant factor to predict resistance rates. Resistance rates were higher if cavitary disease was present on radiographs. Furthermore, cavitary disease seems to be additive to prior antituberculosis treatment as a risk factor for drug resistance. Patients who had both of these risk factors present had 71% incidence of drug resistance rates.     

High rate of rifampicin resistance of Mycobacterium tuberculosis in the Taif region of Saudi Arabia.

This retrospective study was undertaken to determine the prevalence and pattern of resistance to antituberculosis drugs among patients with sputum-proven pulmonary tuberculosis who were seen in Taif Chest Hospital over 24 months (between June 1986 and May 1988). The overall prevalence was 22.6% and the majority (53%) were resistant to two drugs. Resistance to streptomycin was most frequent (16%) followed by rifampicin (15%). Resistance to isoniazid was surprisingly low (6.5%). 23.3% of the resistant group had previously received antituberculosis drugs as against 15.4% in the sensitive group. There was a significant association between previous therapy and resistance to antituberculosis drugs. Recommendations to reduce the problem of resistance and to improve compliance are discussed.     

Increased mortality and tuberculosis treatment failure rate among human immunodeficiency virus (HIV) seropositive compared with HIV seronegative patients with pulmonary tuberculosis treated with "standard" chemotherapy in Kinshasa, Zaire

To evaluate their treatment outcomes 170 human immunodeficiency virus (HIV) seropositive and 597 HIV seronegative patients with active pulmonary tuberculosis (TB) treated for 1 yr with "standard" chemotherapy, including streptomycin, isoniazid, and, in most cases, thiacetazone, were traced at completion of therapy. All 582 survivors were invited for reevaluation, and 385 patients, of whom 82 (21.3%) were HIV seropositive, were evaluated. Of those, 325 consenting patients, of whom 67 (20.6%) were HIV seropositive, were followed for 12 months. One year after TB had been diagnosed 47 (31.3%) of the 150 HIV seropositive and 22 (4.4%) of the 501 HIV seronegative patients traced had died (p = 10(-6]. During the subsequent year the mortality of 67 HIV seropositive patients (26.3/100 patient-years) was higher than that of the 303 HIV seronegative patients (2.2/100 patients-years, p = 10(-6]. HIV seropositive patients had a higher overall TB therapy failure rate 24 months after the diagnosis of TB than did HIV seronegative patients (21.1/100 patient-years versus 8.1/100 patient-years, p = 0.002), mainly because their relapse rate of pulmonary TB (18.1/100 patient-years) was higher than that of HIV seronegative patients (6.0/100 patient-years, p = 0.03). Given their higher relapse rate after 1 yr of "standard" chemotherapy, the public health impact of routine maintenance therapy in HIV seropositive patients with pulmonary TB who complete such therapy should be assessed in comparison to the introduction of rifampicin-based short-course antituberculosis chemotherapy in developing countries.     

The Relevance of Biopsy in Tuberculosis Patients Without Human Immunodeficiency Virus Infection

Although chronic granulomatous inflammation (CGI) with concomitant caseous necrosis (CN) is a characteristic histological feature of tuberculosis (TB), few studies have investigated its frequency or various pathologic findings. The medical records of 227 human immunodeficiency virus (HIV) -negative, culture-positive TB patients who underwent biopsy were studied. After the frequency of characteristic pathological findings of TB was determined, a pathologist reanalyzed the pathological findings with particular focus on necrosis and reclassified CGI, CN, or possible CN into possible TB pathologic findings. The initial biopsy interpretation revealed that 63 (34.8%) of 181 patients with pulmonary TB had caseating granulomas, 36 (19.9%) patients had only CGI, and 6 (3.3%) patients had only CN. Among 46 patients with extrapulmonary TB, 16 (34.8%) patients had only caseating granulomas, and 14 (30.4%) patients had only CGI. More patients who underwent percutaneous lung biopsy had CGI or CN (76.3%) than patients who underwent transbronchial lung biopsy (53.6%). The reanalysis confirmed all CN cases identified by the first interpretation, and 20 (95.2%) of 21 non-CN cases were reclassified as possible CN. Ten cases (three pulmonary and seven extrapulmonary) were reclassified as possible TB pathologic findings from just necrosis. Caseating granuloma was present in only one-third of TB cases. Even in cases where only necrosis was identified, CN may be present.     

Tuberculosis antigen A60 serodiagnosis in tuberculous infection: Application in extrapulmonary and smear-negative pulmonary tuberculosis

Abstract An ELISA diagnostic test for tuberculosis antigen A60 (TBA60) IgG/IgM was used in a tertiary referral hospital in Taiwan. From June 1992 to December 1993, serum samples obtained from 907 patients were analyzed for TBA60 IgG and IgM titres. The final diagnosis of these patients was confirmed by microbiological study and clinical follow up for 18–24 months. Among 147 patients with active pulmonary tuberculosis, IgG was positive in 112 (76.2%), IgM was positive in 14 (9.52%). Among 90 patients with active extrapulmonary tuberculosis, IgG was positive in 53 (58.9%), IgM was positive in 9 (10%). Among 153 patients with inactive tuberculosis, IgG was positive in 28 (18.3%), IgM was positive in 1 (0.6%). Among 517 patients with nontuberculous disease, IgG was positive in 50 (9.7%), IgM was positive in 3 (0.6%). In this study population with 26% (237/907) active tuberculous infection rate, the TBA60 ELISA IgG had a diagnostic sensitivity of 69.6% and a specificity of 92.1%. These results indicate a positive predictive value of 67.9% and a negative predictive value of 89.2%. The sensitivity of IgM was 10.5% and specificity, 99.4%. The serum IgG titre had good correlation with the extent of pulmonary disease. Patients with smear-positive pulmonary TB had a higher percentage of IgG seropositivity (83.9%) than those with smear-negative pulmonary TB (70.6%) and extrapulmonary TB (58.9%). In 50 cases with active tuberculosis, follow- up examinations were carried out one month after treatment. In 18 cases with initially negative IgG and IgM titres, 13 showed elevation of serum IgG titres into positive level, one had positive seroconversion of IgM which was the only serological marker indicating active infection. Therefore, 77.8% (14/18) gained diagnostic benefit from follow-up serological examination. It was concluded that TBA60 IgG and IgM ELISA is a useful test when diagnosing tuberculosis. This test also assists in the clinical judgement of tuberculosis when used as an adjunct to symptoms and sputum smear, and for monitoring therapeutic response at the commencement of treatment.     

Initial roentgenographic manifestations of bacteriologically proven Mycobacterium tuberculosis. Typical or atypical?

Admission chest roentgenograms were reviewed of all patients diagnosed with pulmonary and extrapulmonary tuberculosis (TB) at the Medical College of Georgia--Eugene Talmadge Memorial Hospital (MCG-ETMH) during a five-year period from 1979 to 1983. Of 75 patients included, 51 had pulmonary TB, whereas 24 had extrapulmonary infection. Cavitary disease was common (28 of 51 patients with pulmonary TB). Forty-four of 51 patients with pulmonary TB had involvement of apical and/or posterior segments of the upper lobes with cavitation or infiltrates. Pleural effusion, parenchymal nodules, lymphadenopathy, and lower lung field disease were uncommon. Thirteen of 24 patients with extrapulmonary TB had abnormal admission chest roentgenograms, suggesting the possibility of Mycobacterium tuberculosis infection. Despite recent studies suggesting that TB presents with atypical roentgenographic features more commonly than reported in the past, the roentgenographic manifestations of TB in our series were typical of those previously described as pathognomonic for the disease.     

Pulmonary tuberculosis in children with Hodgkin's lymphoma

The clinical presentation of tuberculosis (TB) and Hodgkin's lymphoma (HL) with pulmonary involvement is similar and raises problems of differential diagnosis. It may also be difficult to distinguish TB from relapsed lymphoma. The purpose of this study was to evaluate the association of HL and pulmonary TB and to discuss differential diagnosis. Medical records of 70 children were reviewed retrospectively. A total of 27 patients (38%) had mediastinal-pulmonary involvement initially. Systemic symptoms were present in 37 (52%) patients. In all, 14 patients (20%) had pulmonary TB; three of them were diagnosed as having TB before HL, two of them had TB and HL concomittantly at initial diagnosis, seven of them during lymphoma therapy and two of them after the cessation of lymphoma treatment. PPD was positive (>10 mm) only in seven patients. In all, 11 patients with pulmonary TB had diffuse pulmonary infiltrations and mediastinal enlargement at lung contrast-enhanced computed tomography and X-ray, which was difficult to differentiate from HL. Biopsies were performed in five patients. No mortality because of the infection was seen. Only one patient had been lost as relapsed-resistant HL. To evaluate mediastinal lymphadenopathies is very crucial and the differential diagnosis is difficult; hence the association between HL and the TB must be considered especially in countries where TB is highly endemic.     

综合医院以不明原因发热为表现的结核病100例临床分析

目的 探讨以不明原因发热(FUO)为表现的结核病的临床特征.方法 回顾性分析100例北京协和医院确诊的以FUO为表现的结核病患者的临床资料.结果 (1)结核累及部位:单纯肺结核39例,单纯肺外结核28例,肺结核合并肺外结核33例.(2)临床表现:由于累及部位的不同,伴随症状各异.实验室检查多为ESR增快和C反应蛋白升高以及不同程度的消耗表现即贫血和低白蛋白血症.(3)诊断方法:抗酸杆菌阳性的34例,组织病理符合结核病的8例,临床诊断并经抗结核治疗有效的49例,诊断性抗结核治疗有效的9例.从发病至确诊的时间为3～77周,中位确诊时间14周.(4)治疗反应:73例随访的患者中仅有2例(2.7%)死亡,其余均好转或治愈.正规抗结核治疗4周以内显效率为77.5%.37例(52.1%)出现药物不良反应,经调整治疗方案和对症处理后均好转.结论 以FUO为表现的结核病诊断比较困难,应对该病临床表现进行综合分析,认真阅读胸部影像学资料,尽可能寻找病原学和病理学的证据,必要时可给予诊断性抗结核治疗.     

Hypercalcemia in patients with newly diagnosed tuberculosis in Abuja, Nigeria

BACKGROUND

The prevalence of hypercalcemia has not previously been determined in newly diagnosed tuberculosis (TB) patients in Nigeria.

OBJECTIVE

To determine the incidence of hypercalcemia in Nigerian patients with newly diagnosed TB before the commencement of anti-TB treatment.

METHODS

The present study is a prospective examination of consecutive patients with newly diagnosed TB confirmed by bacteriological and/or histological methods at the National Hospital (Abuja, Nigeria) from January 2004 to December 2004.

RESULTS

Of 120 patients (70 males and 50 females), 70 had pulmonary TB, 10 had pulmonary and pleural TB, 20 had pleural TB without radiographic evidence of lung involvement, 18 had various other forms of extrapulmonary TB and two had disseminated TB. The mean age of the patients was 38.3±12.0 years. The mean albumin-adjusted serum calcium concentration was 2.53±0.22 mmol/L. Hypercalcemia was present in 27.5% of the patients, but only 12% of these patients showed symptoms of hypercalcemia. The type of TB and, in the case of pulmonary TB, the extent of lung involvement, had no effect on the serum calcium concentration.

CONCLUSION

Hypercalcemia is not uncommon among Nigerian patients with newly diagnosed TB, but it is rarely symptomatic.     

Tuberculosis in renal transplant recipients

Tuberculosis (TB) has been described in kidney transplant recipients as an infection with predominantly pulmonary involvement. We report the impact of TB in kidney transplantation. Clinical records of adult kidney recipients, transplanted between 1 January 1986 and 31 December 1995 were analyzed for sex, age, graft origin, immunosuppressive therapy, TB sites, diagnostic methods and concomitant infections. Annual incidence, mean time of onset, relation to rejection treatment, tuberculin skin test (PPD) and outcome were analyzed. Patients with a history of TB or graft loss in the first month were excluded. TB was diagnosed in 14 of 384 (3.64%). Mean age at transplantation was 35 years. Twelve of these received the graft from a living donor. All had triple immunosuppression with cyclosporine. Ten had pulmonary TB, three extrapulmonary infection and one disseminated disease. In 13 cases an invasive diagnostic procedure was performed. Mycobacterium tuberculosis cultures were positive in all cases; microscopy revealed acid-fast bacilli (AFB) in 6, and adenosine deaminase was elevated in CSF and pleural effusion in 2. Annual incidence varied from 0% to 3.1%. At the time of TB presentation 8 patients had other concomitant infections (cytomegalovirus, nocardia, Pneumocystis carinii, disseminated herpes simplex virus). Median time of onset was 13 months. Diagnostic results became available post-mortem in 2 cases, and one had TB in a failing allograft. TB was treated with 4 drugs including rifampin in 10 patients. Cyclosporine was discontinued in one, lowered in one and increased in 8. During treatment 5 patients had rejection episodes. At 1 year, graft survival was 72.7% and patient survival 90.9%. TB was more prevalent when recipient and donor were both PPD positive. In summary: although TB is a growing threat in the transplant setting, early and aggressive diagnosis with meticulous monitoring of immunosuppression allows a successful outcome for both patient and graft. Optimal prophylaxis guidelines have yet to be completely defined.     

Tuberculosis in HIV/AIDS patients: a Malaysian experience

This retrospective study was conducted at the National Tuberculosis Center (NTBC) where 252 HIV-positive patients coexisting with tuberculosis (TB/HIV) were examined. We found that patients with pulmonary (PTB) and extrapulmonary tuberculosis (EPT) had similar mean age. A higher sex ratio between male to female (10.7:1) was observed in patients with PTB. The other characteristics of patients with pulmonary and extrapulmonary tuberculosis were not statistically different from each other. Cough (88%) and hemoptysis were the most common presenting symptoms, significantly related to patients with PTB. Lymphadenopathy (33.5%) was the most common sign in patients with EPT. The majority of patients with pulmonary and extrapulmonary tuberculosis had CD4 cell counts of less than 200 cells/mm3 (range 0-1,179 with a median of 57 cells/mm3). Lung (89%) and miliary (55.6%) forms were the most frequent disease locations in patients with PTB and EPT, respectively. A higher percentage of patients with PTB (42%) were treated successfully with short-course (6 months) therapy, whereas in patients with EPT (43%) needed a longer period (9 months) for successful treatment. Of the patients who defaulted treatment, a higher proportion (87%) had PTB. No MDR-TB or relapse cases were found in this study.     

Efficacy and safety of cholecalciferol-augmented anti-tuberculosis therapy for treatment of naïve patients with pulmonary tuberculosis: A randomized,controlled, clinical study

Background/objectiveVitamin D deficiency may contribute to the therapeutic failure of antituberculosis therapy (ATT). The aim of this study is to explore the role of adding cholecalciferol to the standard ATT in improving the therapeutic outcome among the naïve patients with pulmonary tuberculosis (TB).MethodsA randomized, controlled, clinical study, which included 496 naïve patients with pulmonary TB, was carried out. The patients were randomly allocated to two groups. Group-A included 247 patients who received ATT, while group-B included 249 patients who received ATT with cholecalciferol.ResultsThe rate of therapeutic failure among the study population was 29.4%; it was significantly lower among patients of group-B compared to those of group-A (22.1% (95% CI 14.7–26.2) vs 38.1% (95% CI 31.5–46.1), p 0.036). In addition, the rate of early therapeutic response was significantly higher among patients of group-B compared to those of group-A (35.3% (95% CI 29.6–42.3) vs 19.4% (95% CI 15.1–24.6), p 0.041). Incidence rate of adverse effects was 19.3%; it was higher (although not statistically significant) among patients of group-A compared to those of group-B (21.9% vs 16.9%).ConclusionsIn conclusion, cholecalciferol-augmented ATT can be more efficacious in treating naïve patients with pulmonary TB compared to the standard ATT. In addition, adding vitamin D3 to ATT provides extra protection against the hepatic and muscular adverse effects of ATT.     

广东省肇庆地区结核病初始耐药发展趋势

目的　本文对肇庆地区1 996～2 0 0 4年新发初治菌阳肺结核病人1 2 4 2例的初始耐药情况进行分析。结果　发现初始耐药率由2 8.4%下降至1 9.4%。耐多药率有上升趋势,由8.9% ,上升为1 2 .7%。结论　提示初治病人需开展药敏试验,以制定最佳的化疗方案,避免耐多药菌的产生和传播。     

Tratamiento de la enfermedad tuberculosa pulmonar y extrapulmonar

The purpose of tuberculosis treatment is twofold: to provide an individual benefit centred on healing the patient with TB, and to provide a collective benefit to the community in which the patient resides. The different treatment regimens for tuberculosis sensitive to first-line antituberculosis drugs as well as resistant tuberculosis are examined and the peculiarities in the management of pulmonary and extrapulmonary tuberculosis are discussed.     

Use of a T cell interferon gamma release assay in the investigation for suspected active tuberculosis in a low prevalence area

Background

In settings with low background prevalence of tuberculosis (TB) infection, interferon-γ release assays (IGRA) could be useful for diagnosing active TB. This study aims to evaluate the performance of QuantiFERON^®-TB Gold (QFT-G) in the investigation for suspected active TB, with particular attention to patients originating in high-incidence countries. Furthermore, factors associated with QFT-G results in patients with active TB were assessed.

Methods

From patients investigated for clinically suspected active TB, blood was obtained for QFT-G testing, in addition to routine investigations. Positive (PPV) and negative (NPV) predictive values for QFT-G were calculated, comparing patients with confirmed TB and those with other final diagnoses. QFT-G results in TB patients originating from countries with intermediate or high TB incidence were compared with QFT-G results from a control group of recently arrived asymptomatic immigrants from high-incidence countries. Factors associated with QFT-G outcome in patients with confirmed TB were assessed.

Results

Among 141 patients, 41/70 (58.6%) with confirmed TB had a positive QFT-G test, compared to 16/71 (22.6%) patients with other final diagnoses, resulting in overall PPV of 71.9% and NPV of 67.6%. For patients with pulmonary disease, PPV and NPV were 61.1% and 67.7%, respectively, and 90.5% and 66.7% for subjects with extrapulmonary manifestations. Comparing patients from high-incidence countries with controls yielded a PPV for active TB of 76.7%, and a NPV of 82.7%. Patients with confirmed TB and positive QFT-G results were characterized by a lower median peripheral white blood cell count (5.9 × 10⁹/L vs. 8.8 × 10⁹/L; P < 0.001) and a higher median body mass index (22.7 vs. 20.7; P = 0.043) as compared to QFT-G-negative TB patients.

Conclusion

The overall PPV and NPV of QFT-G for identifying active TB were unsatisfactory, especially for pulmonary disease. Thus, the usefulness of QFT-G for this purpose is questionable. However, a high PPV was observed for extrapulmonary TB and QFT-G might be considered in the diagnostic process in this situation. The PPV and NPV for identifying active TB among persons originating from regions with high-and intermediate TB incidence was similar to that observed in subjects originating in the low-incidence region.