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Background: Leprosy is a chronic and disabling infectious disease caused by Mycobacterium leprae. It has a wide clinical spectrum and is operationally classified into paucibacillary (PB) and multibacillary (MB) cases. There is evidence that the 16S rRNA gene can be used in Polymerase Chain Reaction (PCR) for complementary detection with high sensitivity and specificity. However, there is no literature convention on its diagnostic correspondence regarding the particular operational classification of the disease. This study aimed to correlate, through a meta-analysis, the detection rate of leprosy between the PCR method with the 16S rRNA gene in the clinical forms PB and MB in relation to confirmed cases. Methods: This is a systematic review and meta-analysis study conducted according to the PRISMA 2020 guidelines, using the search descriptors with "AND": "Leprosy"; "Polymerase Chain Reaction"; "16S rRNA" in the PUBMED, SciELO, LILACS, and Science Direct databases. The search was limited to original observational articles in Portuguese, English, or Spanish, with no defined time frame. The methodological quality assessment of the selected articles was performed using the JBI checklists. A scientometric approach to the article using used the VOS Viewer and Scimago Graphica software. The meta-analysis was conducted using Comprehensive Meta-Analyses software, under Pearson's Correlation effect test and fixed effect model and subgroup analysis concerning the type of sample analyzed. Results: The study was significant from the perspective of the paucibacillary group (Clinical biopsy: -0.45 [95% CI= -0.63 - -0.22], p < 0.001/Slit smear skin: -0.52 [95% CI= -0.65 - -0.36], p < 0.001 / Overall: -0.50 [95% CI= -0.61 - -0.37], p < 0.001). The PCR diagnostic method for the16S rRNAgene of M. lepraehas low viability and diagnostic sensitivity in both clinical biopsy samples and leprosy skin smears. Conclusion: This implies little validation of it as a PCR target gene for diagnosing the disease, highlighting limitations in the actual technique. [ABSTRACT FROM AUTHOR]

BackgroundLeprosy is a chronic and disabling infectious disease caused by Mycobacterium leprae. It has a wide clinical spectrum and is operationally classified into paucibacillary (PB) and multibacillary (MB) cases. There is evidence that the 16S rRNA gene can be used in Polymerase Chain Reaction (PCR) for complementary detection with high sensitivity and specificity. However, there is no literature convention on its diagnostic correspondence regarding the particular operational classification of the disease. This study aimed to correlate, through a meta-analysis, the detection rate of leprosy between the PCR method with the 16S rRNA gene in the clinical forms PB and MB in relation to confirmed cases.MethodsThis is a systematic review and meta-analysis study conducted according to the PRISMA 2020 guidelines, using the search descriptors with “AND”: “Leprosy”; “Polymerase Chain Reaction”; “16S rRNA” in the PUBMED, SciELO, LILACS, and Science Direct databases. The search was limited to original observational articles in Portuguese, English, or Spanish, with no defined time frame. The methodological quality assessment of the selected articles was performed using the JBI checklists. A scientometric approach to the article using used the VOS Viewer and Scimago Graphica software. The meta-analysis was conducted using Comprehensive Meta-Analyses software, under Pearson’s Correlation effect test and fixed effect model and subgroup analysis concerning the type of sample analyzed.ResultsThe study was significant from the perspective of the paucibacillary group (Clinical biopsy: -0.45 [95% CI= -0.63 – −0.22], p

The diagnosis of paucibacillary (PB) leprosy often possesses a diagnostic challenge, especially for pure neuritic and lesser skin lesions with the zero bacillary load, requiring a sensitive and accurate diagnostic tool. We have included 300 clinically diagnosed new leprosy cases (comprising 98 PB cases) and analyzed the sensitivity and specificity of PB leprosy cases by nested PCR with folP , gyrA , rpoB , RLEP , and 16SrRNA and Enzyme-linked Immunospot Assay test (ELISPOT) with MMPII, NDO-BSA, and LID-1 antigens by detecting interferon gamma (IFN-γ) release. The overall positivity rates of genes tested in 300 clinical specimens were identified as 55% of 16SrRNA , 59% of RLEP , 59.3% of folP , 57.3% of rpoB , 61% of gyrA while 90% of nested folP , 92.6% of nested rpoB , and 95% of nested gyrA , and 285 (95%) of at least one gene positive cases. For PB specimens, 95% PCR positivity was achieved by three tested genes in nested PCR. The data obtained from ELISPOT for three antigens were analyzed for IFN-γ expression with 600 subjects. Among 98 PB leprosy cases, the sensitivity of MMP II, LID-1, and NDO-BSA was 90%, 87%, and 83%, respectively, and the specificity was 90%, 91%, and 86%, respectively. The total number of cases positive for at least one antigen was 90 (91.8%) in PB, which is significantly higher than that in multibacillary (MB) leprosy (56.7%). The combination of multi-targets nested PCR and ELISPOT assay provides a specific tool to early clinical laboratory diagnosis of PB leprosy cases. The two assays are complementary to each other and beneficial for screening PB patients. [ABSTRACT FROM AUTHOR]

The diagnosis of paucibacillary (PB) leprosy often possesses a diagnostic challenge, especially for pure neuritic and lesser skin lesions with the zero bacillary load, requiring a sensitive and accurate diagnostic tool. We have included 300 clinically diagnosed new leprosy cases (comprising 98 PB cases) and analyzed the sensitivity and specificity of PB leprosy cases by nested PCR with folP, gyrA, rpoB, RLEP, and 16SrRNA and Enzyme-linked Immunospot Assay test (ELISPOT) with MMPII, NDO-BSA, and LID-1 antigens by detecting interferon gamma (IFN-γ) release. The overall positivity rates of genes tested in 300 clinical specimens were identified as 55% of 16SrRNA, 59% of RLEP, 59.3% of folP, 57.3% of rpoB, 61% of gyrA while 90% of nested folP, 92.6% of nested rpoB, and 95% of nested gyrA, and 285 (95%) of at least one gene positive cases. For PB specimens, 95% PCR positivity was achieved by three tested genes in nested PCR. The data obtained from ELISPOT for three antigens were analyzed for IFN-γ expression with 600 subjects. Among 98 PB leprosy cases, the sensitivity of MMP II, LID-1, and NDO-BSA was 90%, 87%, and 83%, respectively, and the specificity was 90%, 91%, and 86%, respectively. The total number of cases positive for at least one antigen was 90 (91.8%) in PB, which is significantly higher than that in multibacillary (MB) leprosy (56.7%). The combination of multi-targets nested PCR and ELISPOT assay provides a specific tool to early clinical laboratory diagnosis of PB leprosy cases. The two assays are complementary to each other and beneficial for screening PB patients.