Assessment of possible tuberculous lymphadenopathy by PCR compared to non-molecular methods

Abstract

Tuberculosis is a major public health problem in India and other developing countries and has formed a lethal partnership with AIDS. It often presents a diagnostic challenge especially when clinical presentation is suggestive but bacteriological proof is lacking. The objective of this study was to compare the various diagnostic techniques in clinically suspected cases of tubercular lymph nodes and to find a suitable, cost-effective but sensitive and specific method for diagnosis. A total of 100 cases were recruited for the study. Fine needle aspiration cytology was done in all cases and the smears prepared were processed for Giemsa, Ziehl-Neelsen's, Kinyoun and Papanicolaou stains. Parts of the aspirated materials were assessed by fluorescent staining, culture and PCR. Seventyfour percent of aspirates were positive by fluorescent stain while only 22 % were positive by culture. PCR could be performed in 55 cases, out of which 22 (40 %) were positive. When compared to culture, the sensitivity and specificity of PCR were found to be 89 . 5 % and 86 . 1 %, respectively. Fluorescent stain was found to be the most sensitive (81 . 8 %) of the conventional methods but showed poor specificity (28 . 2 %). Interestingly, PCR detected 80 % of smear-negative but culturepositive cases.

Assessment of Clinically Suspected Tubercular Lymphadenopathy by Real-Time PCR Compared to Non-Molecular Methods on Lymph Node Aspirates

“…Published data [20] reports 55% of patients with lymphadenopathy and 22% having fever. Female patients outnumbered males in this study, which is also supported by the published data [19] . These observations reflect biological, hormonal, social, environmental, and behavioural differences between men and women.…”

“…Published data [19,20] indicates that a positive history of contact among TB patients ranges from 13 to 20%; however, in our study the rate was 8.1%. The clinical manifestations of tuberculous lymphadenitis are thought to be through the local manifestation of a systemic disease.…”

Efficacy of TB-PCR Using EBUS-TBNA Samples in Patients With Intrathoracic Granulomatous Lymphadenopathy

“…Similar to pulmonary tuberculosis, TB-PCR using fine needle aspiration samples of cervical, axillary, or inguinal lymph nodes has also been reported as a useful molecular test [16,17]. In the present study, we found that the sensitivity, specificity, positive predictive value, negative predictive value, and overall diagnostic accuracy of TB-PCR using EBUS-TBNA samples in patients with IGL were 56, 100, 100, 81, and 85 %, respectively.…”

Reactive Lymphoid Hyperplasia or Tubercular Lymphadenitis: Can Real-Time PCR on Fine-Needle Aspirates Help Physicians in Concluding the Diagnosis?

“…A few studies [19, 20] do report such instances, with 10.5% PCR-negative and 48% culture-positive cases, but these particular studies considered only cytology-diagnosed TBLN cases, whereas our study was conducted on cytology-diagnosed RLH cases.…”