mRNA and DNA PCR tests in cutaneous tuberculosis

Suthar, Chandanmal; Rana, Tanu; Singh, Urvashi; Singh, Manoj Kumar; Ramesh, V; Sharma, Vinod; Ramam, M

doi:10.4103/0378-6323.104671

Cited by 18 publications

(7 citation statements)

References 22 publications

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“…Other studies have reported PCR positivity in CTB ranging from 5%-77%. [30][31][32][33][34] This variation in results and range is possible because of FFPE tissue being used for the extraction of tubercular DNA. Formalin fixation affects DNA retrieval by 2 main factors: the amount of formalin used and the duration of fixation, 35 which also affects TB-PCR results.…”

Section: Discussionmentioning

confidence: 99%

Diagnostic Utility of Biplex/Multiplex Polymerase Chain Reaction in Infectious Granulomatous Dermatitis in North Indian Population

Parkhi

S²,

De³

et al. 2020

The American Journal of Dermatopathology

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Background: A definite diagnosis of infectious granulomatous dermatitis (IGD) is difficult for both practicing dermatologists and dermatopathologists due to overlapping clinical and histomorphological features. We aimed to explore the role of multiplex polymerase chain reaction (PCR) for identifying a definite etiological agent for diagnosis and appropriate treatment in IGD in formalinfixed paraffin-embedded tissue.Materials and Methods: Sixty-two cases of IGD were included, excluding leprosy. The histochemical stains including Ziehl-Neelsen, periodic acid-Schiff, and Giemsa were performed in all cases. A multiplex PCR was designed for detection of tuberculosis (TB) (IS6110 and mpt64), fungal infections (ITS1, ITS2; ZM1, and ZM3), and leishmaniasis (kDNA). The results of histomorphology, histochemical stains, and multiplex PCR were compared.Results: Among 62 cases, the sensitivity rate of PCR detection for organisms was 16.7%, 0%, 100%, 72%, 75%, and 66.7% in patients with TB, suggestive of TB, leishmaniasis, fungal infections, and granulomatous dermatitis not otherwise specified and granulomatous dermatitis suggestive of fungus, respectively. The TB PCR using IS6110 primers was negative in all cases; however, PCR using mpt64 primers was positive in 33.33% cases of scrofuloderma. The histochemical stains including Ziehl-Neelsen for acid-fast bacilli, periodic acid-Schiff for fungus, and Giemsa for Leishman-Donovan bodies showed positivity in 11.3%, 43.5%, and 3.2%, respectively. Conclusion:A multiplex PCR (Mycobacterium tuberculosis, Leishmania, and panfungal) is highly recommended in all cases of IGD where an etiological agent is difficult to establish by skin biopsy and histochemical stains along with a clinicopathological correlation. This will augment in appropriate treatment and will reduce empirical treatment and morbidity in such patients.

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Section: Discussionmentioning

confidence: 99%

Diagnostic Utility of Biplex/Multiplex Polymerase Chain Reaction in Infectious Granulomatous Dermatitis in North Indian Population

Parkhi

S²,

De³

et al. 2020

The American Journal of Dermatopathology

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“…A possible explanation for this low sensitivity of TB-DNA and TB-RNA assay could be as follows: (1) NTM strains are not in the detection range; (2) the presence of PCR inhibitors; (3) insufficient mycobacteria load and nucleic acid material in some specimens which are possibly caused by the severity of the infection. For the TB-RNA assay, especially the RNA degradation (Suthar et al, 2013 ; Marangu et al, 2017 ).…”

Section: Discussionmentioning

confidence: 99%

Comprehensive Determination of Mycobacterium tuberculosis and Nontuberculous Mycobacteria From Targeted Capture Sequencing

Gong

Zhao

et al. 2020

Front. Cell. Infect. Microbiol.

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Infection of Mycobacterium tuberculosis (MTB) and nontuberculous mycobacteria (NTM) challenges effective pulmonary infectious disease control. Current phenotypic and molecular assays could not comprehensively and accurately diagnose MTB, NTM, and drug resistance. Next-generation sequencing allows an “all-in-one” approach providing results on expected drug susceptibility testing (DST) and the genotype of NTM strains. In this study, targeted capture sequencing was used to analyze the genetic backgrounds of 4 MTB strains and 32 NTM pathogenic strains in 30 clinical samples, including 14 sputum specimens and 16 bronchoalveolar lavage fluid samples. Through comparing with other TB diagnostic tests, we proved that targeted capture sequencing could be used as a highly sensitive (91.3%) and accurate (83.3%) method to diagnose TB, as well as MGIT 960. Also, we identified 7 NTM strains in 11 patients; among them, seven patients were MTB/NTM co-affected, which indicated that it was a meaningful tool for the diagnosis and treatment of NTM infection diseases in clinic. However, based on a drug-resistant mutation library (1,325 drug resistance loci), only 9 drug resistance strains and 22 drug resistance loci were discovered, having considerable discordance with the drug-resistant results of MGIT 960. Our finding indicated that targeted capture sequencing approach was applicable for the comprehensive and accurate diagnosis of MTB and NTM. However, from data presented here, the DST results identified by next-generation sequencing (NGS) showed a relatively low consistency with MGIT 960, especially in sputum samples. Further work should be done to explore the reasons for low drug-resistance detection rate of NGS.

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“…It has a sensitivity ranging between 33% and 96% and specificity of 62.5% for pulmonary tuberculosis. 14 The TST is an useful adjunct in diagnosis of CTb, but it fails to distinguish active and past infections, and can even be negative in some forms of CTb, and in unvaccinated populations, the sensitivity increases to 97%. 6 Besides there is variation seen with the type of lesion, that is, TB chancre, miliary TB, and tuberculous orificialis often show negative TST results, whereas scrofuloderma and lupus vulgaris show strong TST positivity.…”

Section: Tuberculin Skin Testmentioning

confidence: 99%

Diagnostic Dilemma of Cutaneous Tuberculosis: Opening of the Pandora's Box

Chatterjee

Saikia

Ramesh

2021

The American Journal of Dermatopathology

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Tuberculosis in all forms, that is, pulmonary (PTB) or extrapulmonary (EPTB), is a universal health problem. Cutaneous tuberculosis (CTb) remains one of the least studied and often underreported variants of EPTB because of its wide and protean clinical presentation. The diagnosis of CTb remains challenging because of lack of sensitive and specific investigations for its diagnosis. The sensitivity of some of the traditional tests is low because of low concentration of mycobacteria in paucibacillary lesions. Besides it is difficult to distinguish between M. tuberculosis (MTb) and other mycobacterial species in skin biopsies morphologically. Molecular methods may target either MTb DNA or RNA, and serve as promising tools in the diagnosis of various forms of CTb, with high sensitivity and rapidity. This review is focused on diagnostic challenges of CTb and to discuss various methods and newer technologies for diagnosing CTb. This will help the dermatologists and dermatopathologists to elucidate and accurately diagnose CTb from other infectious granulomatous dermatitis for appropriate timely treatment of the patient.

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mRNA and DNA PCR tests in cutaneous tuberculosis

Abstract: The results of PCR tests in cutaneous tuberculosis should be interpreted in the light of clinical and histopathological findings.

Cited by 18 publications

References 22 publications

Diagnostic Utility of Biplex/Multiplex Polymerase Chain Reaction in Infectious Granulomatous Dermatitis in North Indian Population

Diagnostic Utility of Biplex/Multiplex Polymerase Chain Reaction in Infectious Granulomatous Dermatitis in North Indian Population

Comprehensive Determination of Mycobacterium tuberculosis and Nontuberculous Mycobacteria From Targeted Capture Sequencing

Diagnostic Dilemma of Cutaneous Tuberculosis: Opening of the Pandora's Box

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