Pure neuritic leprosy in patients from a high endemic region of Colombia

Rodríguez, Gerzaín; Pinto, Rafael Cuervo; Gómez, Yenny; Rengifo, María Leonor; Estrada, Olga Lucia Troncoso; Sarmiento, Marta Osorio de; López, Fernándo; Beltrán-Alzate, Juan Camilo; Cardona‐Castro, Nora

doi:10.47276/lr.84.1.41

Cited by 16 publications

(6 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In fact, Jardim and coworkers [12] demonstrated that M. leprae infection in PNL cases is diagnosed most often by PCR, followed by anti-PGL-I antibodies and direct observation of the bacteria (acid-fast bacilli [AFB]). Hence, PCR is helpful and is being used as a confirmatory and diagnostic routine tool in difficult-to-diagnose cases such as PNL [60] – [62] .…”

Section: Pcr For Diagnosis Of Difficult Casesmentioning

confidence: 99%

PCR-Based Techniques for Leprosy Diagnosis: From the Laboratory to the Clinic

Talhari²,

et al. 2014

View full text Add to dashboard Cite

In leprosy, classic diagnostic tools based on bacillary counts and histopathology have been facing hurdles, especially in distinguishing latent infection from active disease and diagnosing paucibacillary clinical forms. Serological tests and IFN-gamma releasing assays (IGRA) that employ humoral and cellular immune parameters, respectively, are also being used, but recent results indicate that quantitative PCR (qPCR) is a key technique due to its higher sensitivity and specificity. In fact, advances concerning the structure and function of the Mycobacterium leprae genome led to the development of specific PCR-based gene amplification assays for leprosy diagnosis and monitoring of household contacts. Also, based on the validation of point-of-care technologies for M. tuberculosis DNA detection, it is clear that the same advantages of rapid DNA detection could be observed in respect to leprosy. So far, PCR has proven useful in the determination of transmission routes, M. leprae viability, and drug resistance in leprosy. However, PCR has been ascertained to be especially valuable in diagnosing difficult cases like pure neural leprosy (PNL), paucibacillary (PB), and patients with atypical clinical presentation and histopathological features compatible with leprosy. Also, the detection of M. leprae DNA in different samples of the household contacts of leprosy patients is very promising. Although a positive PCR result is not sufficient to establish a causal relationship with disease outcome, quantitation provided by qPCR is clearly capable of indicating increased risk of developing the disease and could alert clinicians to follow these contacts more closely or even define rules for chemoprophylaxis.

show abstract

Section: Pcr For Diagnosis Of Difficult Casesmentioning

confidence: 99%

PCR-Based Techniques for Leprosy Diagnosis: From the Laboratory to the Clinic

Talhari²,

et al. 2014

View full text Add to dashboard Cite

show abstract

“…More recently, real-time PCR has improved the rate of disease detection by facilitating the direct quantitation of the bacterial DNA content in clinical samples, thereby increasing the reliability of the results [ 9 – 11 ]. This tool has become particularly important in the differential diagnosis of cases with a negative bacillary load and non-conclusive histopathology [ 12 – 14 ].…”

Section: Introductionmentioning

confidence: 99%

Quantitative polymerase chain reaction in paucibacillary leprosy diagnosis: A follow-up study

et al. 2019

View full text Add to dashboard Cite

ObjectiveThe diagnosis of paucibacillary (PB) leprosy cases remains a challenge because of the absence of a confirmatory laboratory method. While quantitative polymerase chain reaction (qPCR) has been shown to provide reliable sensitivity and specificity in PB diagnoses, a thorough investigation of its efficacy in clinical practice has not yet been published. The present study evaluated patients with suspected leprosy skin lesions by using qPCR to identify PB individuals in the Leprosy Outpatient clinic at the Oswaldo Cruz Foundation in Rio de Janeiro, Brazil.MethodsOne hundred seventy-two suspected PB cases were included in the study. The patients were evaluated by a dermatologist at three different times. The clinical dermato-neurological examination and collected samples were performed on the first visit. On the second visit, the results of the histopathological analysis and PCR assay (DNA-based Mycobacterium leprae qPCR-targeting 16S gene) results were analyzed, and a decision regarding multi-drug therapy was made. A year later, the patients were re-examined, and the consensus diagnosis was established.ResultsIn 58% (100/172) of cases, a conclusive diagnosis via histopathological analysis was not possible; however, 30% (30/100) of these cases had a positive PCR. One hundred ten patients (110/172) attended the third visit. The analysis showed that while the sensitivity of the histopathological test was very low (35%), a qPCR alone was more effective for identifying leprosy, with 57% sensitivity.ConclusionThe use of qPCR in suspected PB cases with an inconclusive histology improved the sensitivity of leprosy diagnoses.

show abstract

“…Over the last two to three decades, detection and identification of M. leprae DNA in various tissues has proven to be a useful tool in diagnosing leprosy. [21][22][23] Direct detection of AFB in slit-skin smears has a high specificity but low sensitivity, as approximately 50% of all leprosy patients are SSS negative. 24,25 In the current cohort, SSS was negative in all cases when it was performed, and skin biopsy revealed nonspecific granulomas in only 4/18 cases, and none showed AFB.…”

Section: Discussionmentioning

confidence: 99%

Appropriately Selected Nerve in Suspected Leprous Neuropathy Yields High Positive Results for Mycobacterium leprae DNA by Polymerase Chain Reaction Method

Vengalil

Lavania²,

Singh³

et al. 2020

The American Journal of Tropical Medicine and Hygiene

View full text Add to dashboard Cite

Identification of Mycobacterium leprae DNA by polymerase chain reaction (PCR) is a reliable and an affordable method to confirm leprosy. DNA from 87 nerve samples (61 from paraffin blocks and 26 fresh samples) was extracted. Mycobacterium leprae DNA was amplified by PCR from 80/87 (92%) specimens. Patients were seen over a period of 11 years (2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015)(2016)(2017)(2018)(2019), and leprosy was diagnosed based on clinical and characteristic histopathology findings. The clinical diagnostic possibilities were as follows: leprous neuropathy in 73/80 (91.3%), mononeuritis multiplex of unknown etiology in four (5.0%), vasculitic neuropathy in two (2.5%), and distal symmetric sensory motor neuropathy in one (1.3%). The biopsied nerves were as follows: superficial radial = 34 (42.6%), dorsal cutaneous branch of ulnar = 19 (23.8%), sural = 18 (22.5%), and superficial peroneal = 9 (11.3%), and corresponding neurological deficits were recorded in 77 (96.3%) cases. The histopathological diagnoses in total group were as follows: (borderline tuberculoid (BT) = 52, tuberculoid (TT) = 8, borderline lepromatous (BL) = 8, borderline borderline (BB) = 3, nonspecific inflammation = 3, healed/ fibrosed = 4, and axonopathy = 2). Acid fast bacilli (AFB) was demonstrated in 11 (13.7%) samples. For comparison, 31 clinically and histopathologically defined non-leprous disease control nerves (inherited neuropathy = 20, vasculitis = 8, and nutritional neuropathy = 3) subjected to PCR were negative for M. leprae DNA. In most instances, there are multiple thickened peripheral nerves in suspected cases of leprosy, but neurological deficits pertaining to the thickened nerve are not as widespread. The current findings emphasize the importance of selecting the most appropriate nerve for biopsy to obtain a positive PCR result. We infer that clinical, histopathological, and PCR tests complement each other to help achieve a definitive diagnosis of leprosy particularly in pure neuritic leprosy and in leprous neuropathy with negative skin smears/biopsy.

show abstract

Pure neuritic leprosy in patients from a high endemic region of Colombia

Cited by 16 publications

References 18 publications

PCR-Based Techniques for Leprosy Diagnosis: From the Laboratory to the Clinic

PCR-Based Techniques for Leprosy Diagnosis: From the Laboratory to the Clinic

Quantitative polymerase chain reaction in paucibacillary leprosy diagnosis: A follow-up study

Appropriately Selected Nerve in Suspected Leprous Neuropathy Yields High Positive Results for Mycobacterium leprae DNA by Polymerase Chain Reaction Method

Contact Info

Product

Resources

About