Clinical value of whole-blood interferon-gamma assay in patients with suspected pulmonary tuberculosis and AFB smear- and polymerase chain reaction-negative bronchial aspirates

Mycobacterium kansasii Pneumonia with Mediastinal Lymphadenitis in a Patient with Acute Myeloid Leukemia: Successful Treatment to Stem Cell Transplantation

Non-tuberculous mycobacterial (NTM) disease is a relatively rare cause of neutropenic fever in patients with hematologic malignancies. During the neutropenic period, performing invasive procedures for microbiological or pathological confirmation is difficult. In addition, the optimal treatment duration for NTM disease in patients with leukemia, especially prior to stem cell transplantation (SCT), has not been documented. Therefore, we report a case of pneumonia with necrotizing lymphadenitis caused by Mycobacterium kansasii diagnosed during chemotherapy being performed for acute myeloid leukemia. The radiologic findings were similar to those of invasive fungal pneumonia; however, a bronchoalveolar washing fluid culture confirmed that the pathogen was M. kansasii. After 70 days from starting NTM treatment, allogeneic SCT was performed without any complications. The patient fully recovered after 12 months of NTM treatment, and neither reactivation of M. kansasii infection nor related complications were reported.

Different characteristics of tuberculous pleural effusion according to pleural fluid cellular predominance and loculation

BACKGROUND

Tuberculous pleural effusion (TPE) exhibits different characteristics according to pleural fluid cellular predominance or whether the pleural fluid is free-flowing or loculated. However, its categorization based on either of these factors alone may be insufficient to properly reflect the heterogeneous manifestation of TPE. We evaluated the characteristics of the four TPE groups classified according to cellular predominance and whether the fluid is free-flowing or loculated.

METHODS

A cohort of 375 patients with TPE was retrospectively reviewed. Clinical, radiological, and laboratory findings were compared between neutrophilic and lymphocytic TPE, and between free-flowing and loculated effusion for both neutrophilic and lymphocytic TPE.

RESULTS

Lymphocytic TPE and neutrophilic TPE were observed in 336 (90%) and 39 (10%) patients, respectively. Pleural fluid loculation was present in 36% and 31% of the patients in the lymphocytic and neutrophilic groups, respectively. A few parameters of the laboratory findings between neutrophilic and lymphocytic TPE patients showed significant differences. However, these significant differences were prominently observed when comparing free-flowing and loculated subgroups of the respective neutrophilic and lymphocytic groups. Pleural fluid pH, lactate dehydrogenase, and adenosine deaminase levels were significantly different among the four subgroups. The neutrophilic loculated subgroup exhibited the most intense pleural inflammation and the highest mycobacterial yields when compared to the other subgroups. However, the percentage of neutrophils in the pleural fluid was not positively associated with the probability of culture-positive effusion.

CONCLUSIONS

The heterogeneous manifestation of TPE would be better characterized by using a classification system based on combined pleural fluid cellular predominance and loculation, with the neutrophilic loculated subgroup contributing to most of the clinically significant differences.

Neutrophilic Loculated Tuberculous Pleural Effusion: Incidence, Characteristics and Differentiation From Complicated Parapneumonic Effusion

OBJECTIVES

Tuberculous pleural effusion (TPE) is generally characterized by lymphocytic exudative effusion, either free-flowing or loculated. However, patients can also have neutrophilic loculated TPE, although little data are available concerning the incidence and characteristics of this form of TPE. It is important to differentiate between neutrophilic loculated TPE and complicated parapneumonic effusion (PPE), which also shows neutrophilic loculated effusion but needs a different management approach. The present study evaluated the incidence and characteristics of neutrophilic loculated TPE and differentiated it from complicated PPE.

MATERIALS AND METHODS

Between 2009 and 2014, a cohort of patients with TPE was retrospectively reviewed in a South Korean referral hospital. Clinical, laboratory, computed tomography and pleural fluid findings of patients with neutrophilic loculated TPE were compared to those of patients with neutrophilic free-flowing TPE and complicated PPE, respectively.

RESULTS

Neutrophilic TPE was observed in 33 (10%) out of 344 patients with TPE. Of these, 10 (30%) patients exhibited loculation of the pleural fluid. These patients showed distinct pleural fluid characteristics. The classical pleural fluid biomarker levels were more intense than those observed in 23 patients with neutrophilic free-flowing TPE, but similar to those of 54 patients with complicated PPE. A high mycobacterial burden was observed in the pleural fluid, and favorable outcomes were achieved with antituberculosis drug administration alone. Nodular parenchymal lesions and pleural fluid adenosine deaminase levels were independent discriminators of neutrophilic loculated TPE and PPE.

CONCLUSIONS

These results may be helpful to understand and manage patients with neutrophilic loculated TPE and differentiate them from patients with complicated PPE.

Radiologic and laboratory differences in patients with tuberculous and parapneumonic pleural effusions showing non-lymphocytic predominance and high adenosine deaminase levels

PURPOSE

Tuberculous pleural effusion (TPE) is characterized by lymphocytic predominance and high adenosine deaminase (ADA) levels. However, TPEs sometimes present non-lymphocytic predominance, and parapneumonic effusion (PPE) often exceeds the cutoff value of ADA for TPE. Thus, the differential diagnosis of cases with pleural fluid (PF) showing non-lymphocytic predominance and high ADA levels is challenging. However, limited data concerning the clinical differences in these patients are available.

METHODS

A retrospective study was conducted on TPE and PPE patients with PF showing non-lymphocytic predominance and ADA levels ≥40 U/L in 2009-2013 in a South Korean tertiary referral hospital. The clinical, laboratory, and computed tomography (CT) findings between the groups were analyzed using multivariate logistic regression to develop a prediction model with independent factors for TPE.

RESULTS

Among 353 patients with TPE, 24 (6.8 %) showed PF with non-lymphocytic predominance and ADA levels of ≥40 U/L. Twenty-eight PPE patients who presented PF findings comparable with those of TPE patients were included in the control group. In the final analysis, PF ADA levels >58 U/L and nodular lung lesions on CT were independent positive predictors, while loculated effusion was an independent negative predictor for TPE. Using the prediction model, a score ≥ +3 provided a sensitivity of 88 %, specificity of 93 %, positive predictive value of 91 %, and negative predictive value of 90 % for TPE.

CONCLUSION

PF ADA levels, nodular lung lesions, and loculated pleural effusion may help differentiate TPE from PPE in patients with PF showing non-lymphocytic predominance and ADA levels ≥40 U/L.

Clinical Utility of CT-Based Bronchial Aspirate TB-PCR for the Rapid Diagnosis of Pleural Tuberculosis

Background

Thoracoscopic pleural biopsy is often required for rapid and confirmative diagnosis in patients with suspected pleural tuberculosis (PL-TB). However, this method is more invasive and costly than its alternatives. Therefore, we evaluated the clinical utility of the chest computed tomography (CT)-based bronchial aspirate (BA) TB-polymerase chain reaction (PCR) test in such patients.

Methods

Bronchoscopic evaluation was performed in 54 patients with presumptive PL-TB through diagnostic thoracentesis but without a positive result of sputum acid-fast bacilli (AFB) smear, pleural fluid AFB smear, or pleural fluid TB-PCR test. Diagnostic yields of BA were evaluated according to the characteristics of parenchymal lesions on chest CT.

Results

Chest radiograph and CT revealed parenchymal lesions in 25 (46%) and 40 (74%) of 54 patients, respectively. In cases with an absence of parenchymal lesions on chest CT, the bronchoscopic approach had no diagnostic benefit. BA TB-PCR test was positive in 21 out of 22 (95%) patients with early-positive results. Among BA results from 20 (37%) patients with patchy consolidative CT findings, eight (40%) were AFB smear-positive, 18 (90%) were TB-PCR-positive, and 19 (95%) were culture-positive.

Conclusion

The BA TB-PCR test seems to be a satisfactory diagnostic modality in patients with suspected PL-TB and patchy consolidative CT findings. For rapid and confirmative diagnosis in these patients, the bronchoscopic approach with TB-PCR may be preferable to the thoracoscopy.

Predictive factors for tuberculosis in patients with a TB-PCR-negative bronchial aspirate

PURPOSE

Pulmonary tuberculosis (PTB), with a tuberculosis (TB)-polymerase chain reaction (PCR)-negative bronchial aspirate (BA), but a positive culture result is often encountered in clinical practice. However, limited data are available concerning clinical judgment in patients with suspected PTB and a TB-PCR-negative BA pending culture results. The present study aimed to identify predictors for PTB in patients with a TB-PCR-negative BA.

METHODS

A retrospective study was conducted on patients who had undergone a bronchoscopy because of suspected PTB. Clinical, laboratory, and computed tomography (CT) findings were investigated in PTB patients with TB-PCR-negative but positive culture BA results, and non-PTB patients with a radiographic lesion comparable to the former.

RESULTS

Of 250 patients screened, 31 (12 %) were diagnosed with PTB by positive culture results only. Of these 31 patients, 30 (97 %) had a lesion within one-third of the hemithorax as determined by chest radiography. In the final analysis of 30 PTB and 65 non-PTB patients with comparable radiographic lesions, a positive QuantiFERON-TB Gold In-Tube (QFT) result was independently associated with an increased risk of a positive TB culture. CT findings of consolidation were a negative predictor for PTB. Patients with a negative QFT result and consolidation had a negative predictive value of 95 % for PTB, while patients with a positive QFT result and nodular CT abnormalities without consolidation had a positive predictive value of 86 % for PTB.

CONCLUSION

The simple combination of CT findings of consolidation and QFT test results may help clinicians to refine decision-making in patients with a TB-PCR-negative BA.