Abstract
Abstract
Introduction
Leprosy is a chronic disease caused by the bacillus Mycobacterium leprae and remains a public health concern in endemic countries. Early diagnosis is fundamental to prevent transmission and irreversible disabilities. Histopathological identification of acid-fast bacilli in tissue specimens is traditionally considered the laboratory reference standard; however, its sensitivity is limited, particularly in paucibacillary forms. Immunohistochemistry (IHC) has been proposed as an adjunctive diagnostic tool for detecting M. leprae antigens in tissue samples, but its diagnostic accuracy has not been systematically synthesised. This protocol outlines a systematic review aimed at evaluating the sensitivity and specificity of IHC in the laboratory diagnosis of leprosy.
Methods and analysis
This systematic review of diagnostic test accuracy studies will include analytical observational studies and clinical trials evaluating IHC in human subjects with suspected leprosy. The reference standard will be defined as the identification of acid-fast bacilli in skin biopsy specimens from patients with compatible clinical presentation using conventional staining methods (eg, Fite-Faraco), with the exclusion of alternative mycobacterial infections when applicable. Searches will be conducted in PubMed/MEDLINE (Medical Literature Analysis and Retrieval System Online), Embase, Scopus, Web of Science and BVS/LILACS (Biblioteca Virtual em Saúde/Latin American and Caribbean Health Sciences Literature), as well as grey literature sources, at 31 May 2026. Two independent reviewers will perform study selection, data extraction using a standardised Microsoft Excel form and risk of bias assessment using the Quality Assessment of Diagnostic Accuracy Studies-2. Sensitivity and specificity estimates will be calculated. If appropriate, a bivariate random-effects meta-analysis will be conducted using RevMan (Review Manager) and Stata.
Ethics and dissemination
Ethical approval is not required because this study will use publicly available data. The results will be submitted to a peer-reviewed journal and presented at scientific conferences.
Keywords: Epidemiology, Tropical medicine, Pathology, Infectious diseases & infestations
STRENGTHS AND LIMITATIONS OF THIS STUDY.
Comprehensive search strategy without language or publication date restrictions.
Use of validated methodological tools for diagnostic accuracy reviews, including Quality Assessment of Diagnostic Accuracy Studies-2 and Grading of Recommendations, Assessment, Development and Evaluation.
This protocol follows Preferred Reporting Items for Systematic Review and Meta-analysis of Diagnostic Test Accuracy Studies (PRISMA-DTA) recommendations for systematic review protocols.
The review focuses on an underexplored diagnostic tool for the detection of Mycobacterium leprae.
Expected heterogeneity in immunohistochemistry (IHC) protocols and antibodies may limit comparability between studies.
Introduction
Leprosy is a chronic disease caused by the bacillus Mycobacterium leprae1 and can infect individuals regardless of sex or age group.2 This bacillus is acid-fast and has a cell wall rich in complex lipids, such as mycolic acids and phenolic glycolipid-1 (PGL-1), which protect the bacterium from host defences and are crucial for its pathogenicity, favouring its adhesion and invasion of Schwann cells in the peripheral nervous system. M. leprae has a genome with a large number of pseudogenes, which reflects its adaptation to an obligatory intracellular niche and explains its inability to be cultured in vitro in artificial culture media.3
Despite being one of the oldest diseases known to humankind, leprosy still represents a serious public health problem in many countries, with Brazil ranking as the second country in the world in terms of the number of newly reported cases.4 Diagnosing the disease can be difficult in many cases, especially in the early stages and in paucibacillary forms.1
M. leprae spreads mainly through the respiratory route,5 with the hypothesis that, after transmission, the bacilli adhere to the epithelial cells of the mucosa,6 and a process of haematogenous dissemination of the bacillus may subsequently occur.7
The bacillus exhibits neural tropism, and its bacterial wall contains specific pathogenic components, notably PGL-1, which can bind to laminin-2 of the extracellular basal lamina, which in turn binds to dystroglycan in the plasma membrane of the subcutaneous tissue.3
Leprosy can manifest with various dermatological lesions, including spots, plaques, nodules and others, in addition to potentially causing neurological involvement of the peripheral nervous system, resulting in decreased or lost thermal, painful and tactile sensitivity and muscle strength.8 Involvement of the peripheral nervous system occurs. The lesions vary and involve only small cutaneous branches, a single peripheral nerve, several nerve trunks in an asymmetrical pattern or several peripheral nerves in a symmetrical pattern.9 Cases of leprosy neuropathy can be classified as mononeuropathy, multiple mononeuropathy or polyneuropathy.10
Several classifications have been developed to characterise the clinical forms of leprosy. The Ridley-Jopling classification is comprehensive and lists the following types: tuberculoid-tuberculoid, which is the most localised form, occurring in people who have an effective cellular immune response to the bacillus and a negative skin smear; lepromatous-lepromatous, in which the cellular immune response to the leprosy bacillus is deficient or absent, and the smear is positive and the intermediate forms borderline-tuberculoid, borderline-borderline and borderline-lepromatous.11 There is another classification from the WHO based on the number of skin lesions and nerves affected, called paucibacillary or multibacillary, which was created to facilitate treatment regimens.12
The clinical presentation in leprosy is determined by the manifestation of innate immune resistance. In patients with the tuberculoid form, there is a Th1 response, with a well-defined granuloma infiltrated by CD4+T lymphocytes, containing epithelioid and multinucleated giant cells mediated by cells of the monocytic lineage, and synthesis of interferon-gamma and interleukin-2, with macrophage activation. In cases of lepromatous leprosy, the Th2 response, characterised by the production of interleukin-4, interleukin-5 and interleukin-10, assists in the production of antibodies and, consequently, negatively regulates the cellular immunity induced by the Th1 response, and there is no characteristic granuloma, resulting in an ineffective immune reaction against the bacillus.13 Early diagnosis of leprosy is the most important element in preventing transmission, complications and disabilities.14
The diagnosis is based on clinical, epidemiological and laboratory characteristics. The diagnostic criteria for leprosy include characteristic skin lesions with altered sensitivity, positive bacilloscopy, thickening of a peripheral nerve with related functional impairment, but complementary tests may be necessary, such as histopathological examination, serological examination and PCR for segments of M. leprae DNA, in addition to electroneuromyography and ultrasound of peripheral nerves.15 Histopathological examination is considered the gold standard for diagnosing leprosy,16 and it also allows for precise classification of leprosy forms.17 18
The conventional method of anatomopathological diagnosis of leprosy involves demonstrating acid-fast bacilli, usually using the Fite-Faraco method; however, the use of fluorescence microscopy with auramine-rhodamine staining can allow for more precise quantification of the bacilli with greater sensitivity.19
Another test that could be useful for the diagnosis of some cases of leprosy is immunohistochemistry (IHC).20 The development of IHC began in the 1930s, and the first study using this method was published in 1941.21 From the 1970s onwards, with the refinement of techniques for producing specific monoclonal antibodies, researchers began to apply IHC to study infectious diseases.22 The first article describing the use of IHC to detect M. leprae in tissues was published in 1983.23
Through IHC, it is possible to identify several immunological processes involved in leprosy and leprosy reactions.24 Using monoclonal or polyclonal antibodies, it is possible to detect M. leprae, especially in the initial phases, without depending on bacillary viability;25 therefore, IHC is important for supporting and guiding histopathological diagnosis.16
It is known that there is an apparently specific reactivity of monoclonal antibodies against PGL-1 and lipoarabinomannan in leprosy.26
Other techniques, such as immunofluorescence, can enable the diagnosis of inflammatory and neoplastic diseases; however, they present some improvements compared with IHC, such as loss of fluorescence over time, the need for a specialised light criterion and lower quality for evaluating morphology.27
Current evidence indicates that diagnostic methods for leprosy still have significant limitations.28 In this context, the role of IHC remains insufficiently explored, and evaluating the diagnostic performance of IHC in comparison with established reference standards is particularly relevant. However, the available evidence has not yet been systematically synthesised.
Objectives
The main objective of this systematic review is to identify in the scientific literature the existence of primary studies that characterise the sensitivity and specificity of IHC in the laboratory diagnosis of leprosy in relation to histopathological examination.
The secondary objectives are: (1) to analyse the types of studies that addressed IHC in the laboratory diagnosis of leprosy; (2) to compare the difference in sensitivity of IHC for the diagnosis of paucibacillary and multibacillary forms of leprosy; (3) to describe the antibodies used for IHC in the laboratory diagnosis of leprosy; (4) to list the sensitivity of IHC in the laboratory diagnosis of leprosy in relation to other diagnostic methods, such as PCR testing for segments of M. leprae and serology for leprosy.
Methods and analysis
We conducted a preliminary search of the scientific literature, which revealed the absence of previously published systematic reviews on the subject, and we developed the review protocol.
Statement section
The protocol was prospectively submitted for registration in the Open Science Framework database (OSF Registration DOI: https://doi.org/10.17605/OSF.IO/JFC67), and data can be accessed.
Study design
This protocol will describe a systematic review that will be conducted to synthesise the evidence on the diagnostic accuracy of IHC for laboratory diagnosis of leprosy in relation to histopathological examination, leprosy serology or PCR for M. leprae.
The review will follow the recommendations of the Joanna Briggs Institute Manual for Evidence Synthesis.29
It will also follow the Preferred Reporting Items for Systematic Review and Meta-analysis of Diagnostic Test Accuracy Studies (PRISMA-DTA),30 proposed in the Enhancing the Quality and Transparency of health Research (EQUATOR) Network guidelines.31
Period
The review will be conducted from May 2026 to October 2026.
Team and training
The project team consists of three principal reviewers: a pathologist with experience in IHC, an epidemiologist, a neurologist and a dermatologist. All reviewers will undergo a standardised training programme, which will include theoretical modules on clinical and laboratory aspects of leprosy, principles of IHC, evaluation of diagnostic tests and methodology of systematic reviews. The training will be complemented with practical exercises in data selection and extraction from scientific articles.
Central question of the review
What is the sensitivity and specificity of IHC in the laboratory diagnosis of leprosy in patients of any age, gender, race or ethnicity, compared with histopathological examination or serology? The central question of this review is defined using the acronym PIRD, suitable for reviews of diagnostic tests:
P (population)=subjects of any sex and age with leprosy; It should be noted that a case of leprosy will be defined as a clinically compatible presentation confirmed by histopathology.
I (index test)=IHC examination for leprosy;
R (reference test or gold standard)=histopathological examination identifying acid-fast bacilli by Fite-Faraco staining in patients with compatible clinical presentation.
Comparator tests: PCR assays and serological tests (eg, anti-PGL-1 antibodies).
D (diagnosis of interest)=leprosy.
Databases
A comprehensive search will be conducted in the following electronic databases: Scopus, Embase, Web of Science, PubMed/MEDLINE and BVS/LILACS. Additionally, grey literature sources will be consulted, including Google Scholar, OpenGrey and ProQuest (dissertations and theses).
Population
Studies of children and adults, regardless of age or sex, diagnosed with leprosy will be included.
Eligibility criteria
Inclusion criteria
Studies published and fully available in the defined databases.
Articles from all references of all included studies.
Primary studies with research designs such as clinical trials, analytical observational studies (cohort, case-control or cross-sectional) that evaluate the diagnostic accuracy (sensitivity and specificity) of IHC for the diagnosis of leprosy, using histopathological examination as the gold standard.
Population: human beings of any age or sex, with clinical suspicion of leprosy.
Studies approved by a research ethics committee.
Studies without restrictions on year of publication or language.
Exclusion criteria
Descriptive observational studies (case series, case reports) without a control group.
Non-original publications (letters to the editor, editorials, commentaries, literature reviews).
Studies without explicit approval from a research ethics committee (when applicable).
Duplicate or retracted studies.
Studies whose full text cannot be obtained after contacting the authors.
Search strategy for systematic review
The preliminary search strategy was initially developed with the assistance of a specialised librarian for PubMed/MEDLINE and will be adapted for the other databases according to their specific indexing systems and search requirements.
The search strategy combines controlled terms (MeSH (Medical Subject Headings) and DeCS (Descritores em Ciências da Saúde)) and free keywords related to leprosy, IHC and diagnostic accuracy. There will be no restrictions regarding language or publication date. The reference lists of all included studies and relevant systematic reviews will be manually scanned to identify additional studies.
Search strategy
(Leprosy OR Hansen’s Disease OR Leprosy OR Leprosy OR Hansen’s Disease OR Lèpre OR Hansen’s Disease OR Mycobacterium leprae OR Hansen’s Bacillus OR Bacillus de Hansen OR Bacille de Hansen OR Bacillus leprosy OR Bacille de la Lèpre OR Bacillus de la Lepra) AND (immunohistochemistry OR immunocytochemistry OR immunohistochemistry OR Immunocytochemistry OR Immunohistochimie) AND (Diagnosis OR Diagnostic OR Diagnosis) AND (sensitivity OR sensitivity OR sensitivity OR sensibilité OR accuracy OR accuracy OR precision OR precision OR prevalence OR prevalence OR prevalence OR prevalence).
Study selection process
Citations identified in the searches will be managed in the Rayyan software. The selection process will be carried out in two phases by two independent reviewers:
Title and abstract screening
Reviewers will apply eligibility criteria based on titles and abstracts.
Full-text evaluation
Potentially relevant studies will be retrieved and read in full and reassessed for eligibility. Any disagreements in article selection at any stage will be resolved by consensus or, when necessary, by a third reviewer.
Extraction and analytical management of extracted data
Data extraction will be performed independently by two reviewers using a standardised data extraction form developed in Microsoft Excel, which will be pilot-tested before use.
Information to be extracted includes:
Study characteristics: author, year, country, design and sample size.
Population characteristics: age, sex and clinical forms of leprosy (by Ridley-Jopling and/or WHO classification).
Index test details: antibodies used in IHC, staining protocol and dilution.
Reference test details:
The reference standard will be defined as the histopathological identification of acid-fast bacilli in skin biopsy specimens from patients with clinical findings compatible with leprosy using conventional staining methods (such as Fite-Faraco staining). When reported in the primary studies, alternative mycobacterial infections, particularly cutaneous infections caused by Mycobacterium tuberculosis, should have been excluded through microbiological, molecular or clinical evaluation.
PCR assays will be considered comparative tests only when they use validated primers targeting specific genomic regions of M. leprae and when the study clearly reports the positivity criteria, including cycle limit (Ct) values or other defined detection limits. In extracting PCR data for each included study, the following methodological parameters will be collected: type of PCR assay (conventional PCR or quantitative PCR (qPCR)); target specificity (the PCR assay must target genomic sequences considered specific for M. leprae, such as RLEP or next-generation RLEP -LYON1/LYON2-such as RLEP (Mycobacterium leprae repetitive element) or next-generation RLEP - LYON1/LYON2 (specific primer sequences targeting the RLEP region); primer description (the study must clearly report the primer sequences or the validated primer sets used); definition of positivity (for qPCR assays, the cycle limit -Ct- or equivalent positivity criteria defined by the original study must be reported); laboratory validation (PCR assays must be described as validated by the authors of the original study or based on previously published protocols) and also the verified biological sample (skin biopsy, skin smear or nerve biopsy). Assays targeting the RLEP repetitive element (M. leprae repetitive element) will be accepted, as this is the most widely validated molecular target for the detection of M. leprae due to its high copy number in the bacillus genome and its superior analytical sensitivity. Therefore, conventional PCR assays targeting the RLEP repetitive element and qPCR using RLEP-specific primers (LYON1/LYON2) will be accepted. Sensitivity estimates will be evaluated separately for conventional PCR with RLEP and qPCR-RLEP (LYON1/LYON2). The positivity limits defined for each laboratory will be adopted.
Serology (anti-PGL-1 antibodies) will be considered the comparator. Tests that detect antibodies against PGL-1 or its synthetic derivatives, such as NDO-BSA (natural disaccharide octyl-bovine serum albumin), will only be analysed as comparative tests. Serology will not be considered the gold standard for case definition, since even with a reactive result, antibody titres may reflect past exposure, not active disease, and the diagnostic cut-off values defined by the original study and the related sensitivity and specificity, when available.
Diagnostic accuracy data: true positives, false positives, false negatives, true negatives, sensitivity, specificity, predictive values and/or raw data for their calculation.
Risk of bias and applicability assessment
The methodological quality of the included studies will be assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. This tool assesses the risk of bias and applicability in four domains: patient selection, index test, reference test and test flow and time.32
Data synthesis and statistical analysis
The extracted data will be organised into a narrative synthesis and also through meta-analysis, if possible. A table of study characteristics will be created. The diagnostic accuracy data (sensitivity and specificity) of each study will be plotted in forest plots and receiver operating characteristic curves. If clinical and methodological heterogeneity is acceptable, a meta-analysis will be performed using a bivariate random-effects model to obtain summary estimates of sensitivity and specificity with their respective 95% CIs. The occurrence of heterogeneity will be assessed using Cochran-Q, χ2 statistics and Higgins’ inconsistency test (I2) and assessment of threshold effects.33 Heterogeneity will be investigated through subgroup analyses (such as clinical forms according to the Ridley-Jopling and/or WHO classification or by the types of antibodies used) or meta-regression. Statistical analyses will be performed using RevMan (Review Manager) and Stata software, with the midas command or equivalent packages for meta-analysis of diagnostic tests.
Analysis of publication bias
The risk of publication bias in the meta-analysis will be assessed by constructing funnel plots, based on the logarithmic diagnostic OR as a parameter for the X-axis and with parameters related to sample size on the Y-axis of the graph.
A visual analysis of the funnel plots will be presented using Deeks’ funnel plot skewness test to investigate the presence of publication bias. Deeks’ test is specifically recommended for meta-analyses of diagnostic test accuracy, as it considers the specific sample size instead of the SE.34 A p value <0.10 (or p<0.05) will be considered indicative of significant skewness, indicating the presence of publication bias.
Analysis of the quality of evidence
For the analysis of the quality/certainty of the body of evidence of the diagnostic accuracy meta-analysis, the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) diagnostic instrument will be used.35 To organise and document the judgements, as well as to generate summary of findings tables for the accuracy outcomes, the GRADEpro GDT (Guideline Development Tool) software will be used.36
A comprehensive search strategy for all databases is available in figure 1 through a flowchart that provides a visual mapping of the information flow of the study selection process phases in this systematic review.
Figure 1. Flow diagram of the systematic review based on PRISMA 2020. PRISMA, Preferred Reporting Items for Systematic Review and Meta-analysis.
The complete search strategy for all databases is available in figure 1.
Ethics and dissemination
Ethical approval is not required because this study will use publicly available data. The results will be submitted to a peer-reviewed journal and presented at scientific conferences.
Acknowledgements
We would like to thank the Vice-Rectorate for Research, Graduate Studies and Innovation of the Federal University of Cariri and the Graduate Program in Health Sciences of the Federal University of Sergipe for their support in partially covering the article processing fee.
Footnotes
Funding: The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
prepub: Prepublication history for this paper is available online. To view these files, please visit the journal online (https://doi.org/10.1136/bmjopen-2025-115007).
Provenance and peer review: Not commissioned; externally peer reviewed.
Patient consent for publication: Not applicable.
Patient and public involvement: Patients and/or the public were not involved in the design, conduct, reporting or dissemination plans of this research.
Supplementary material
References
- 1.Froes LAR, Junior, Sotto MN, Trindade MAB. Leprosy: clinical and immunopathological characteristics. An Bras Dermatol. 2022;97:338–47. doi: 10.1016/j.abd.2021.08.006. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Yang J, Li X, Sun Y, et al. Global epidemiology of leprosy from 2010 to 2020: A systematic review and meta-analysis of the proportion of sex, type, grade 2 deformity and age. Pathog Glob Health. 2022;116:467–76. doi: 10.1080/20477724.2022.2057722. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Hess S, Rambukkana A. Cell Biology of Intracellular Adaptation of Mycobacterium leprae in the Peripheral Nervous System. Microbiol Spectr. 2019;7 doi: 10.1128/microbiolspec.bai-0020-2019. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Nascimento Júnior VP, Santos FS, Oliveira JR, et al. Epidemiological analysis of leprosy in Brazil from 2016 to 2020. Res Soc Dev. 2022;11:e24411124988 [Google Scholar]
- 5.Mostafa HMA, Soliman NA, Far NNE, et al. A current perspective on leprosy (Hansen's disease) Int J Dermatol Venereology Leprosy Sci. 2023;6:130–6. doi: 10.33545/26649411.2023.v6.i2b.161. [DOI] [Google Scholar]
- 6.Silva MJA, Silva CS, Brasil TP, et al. An update on leprosy immunopathogenesis: systematic review. Front Immunol. 2024;15:1416177. doi: 10.3389/fimmu.2024.1416177. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.Araujo S, Freitas LO, Goulart LR, et al. Molecular Evidence for the Aerial Route of Infection of Mycobacterium leprae and the Role of Asymptomatic Carriers in the Persistence of Leprosy. Clin Infect Dis. 2016;63:1412–20. doi: 10.1093/cid/ciw570. [DOI] [PubMed] [Google Scholar]
- 8.Serrano-Coll H, Restrepo-Rivera L, Cuadros-Urrego Y, et al. Decoding leprosy: immune response, clinical manifestations and emerging diagnostic approaches. Trans R Soc Trop Med Hyg. 2025;119:988–98. doi: 10.1093/trstmh/traf058. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Scollard DM. The biology of nerve injury in leprosy. Lepr Rev. 2008;79:242–53. [PubMed] [Google Scholar]
- 10.Shukla B, Verma R, Kumar V, et al. Pathological, ultrasonographic, and electrophysiological characterization of clinically diagnosed cases of pure neuritic leprosy. J Peripher Nerv Syst. 2020;25:191–203. doi: 10.1111/jns.12372. [DOI] [PubMed] [Google Scholar]
- 11.Alrehaili J. Leprosy Classification, Clinical Features, Epidemiology, and Host Immunological Responses: Failure of Eradication in 2023. Cureus. 2023;15:e44767. doi: 10.7759/cureus.44767. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Asmin A, Amiruddin MD, Miranti AJ. Characteristics of Leprae Lesions Based on the Ridley Jopling Classification. Literature Review J EduHealth. 2024;15:829–44. [Google Scholar]
- 13.Yasmin H, Varghese PM, Bhakta S, et al. Pathogenesis and Host Immune Response in Leprosy. Adv Exp Med Biol. 2021;1313:155–77. doi: 10.1007/978-3-030-67452-6_8. [DOI] [PubMed] [Google Scholar]
- 14.Dharmawan Y, Fuady A, Korfage IJ, et al. Delayed detection of leprosy cases: A systematic review of healthcare-related factors. PLoS Negl Trop Dis. 2022;16:e0010756. doi: 10.1371/journal.pntd.0010756. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15.Chen K-H, Lin C-Y, Su S-B, et al. Leprosy: A Review of Epidemiology, Clinical Diagnosis, and Management. J Trop Med. 2022;2022:8652062. doi: 10.1155/2022/8652062. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.S M, G S, M R., Dr EXPRESSION OF S100 PROTEIN AND CD1A MARKER IN LESIONS OF LEPROSY. Ijsr. 2022:28–31. doi: 10.36106/ijsr/6400925. [DOI] [Google Scholar]
- 17.Khadilkar SV, Patil SB, Shetty VP. Neuropathies of leprosy. J Neurol Sci. 2021;420:117288. doi: 10.1016/j.jns.2020.117288. [DOI] [PubMed] [Google Scholar]
- 18.Froes Junior LAR, Sotto MN, Trindade MAB. Leprosy in the 21st century: a comprehensive review of immunological mechanisms, diagnosis, and treatment. Rev Inst Med Trop Sao Paulo. 2025;67:e74. doi: 10.1590/S1678-9946202567074. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 19.Soni S, Walke V, Asati D, et al. Fluorescent Microscopy: A Useful and Adjunct Tool in Leprosy Diagnosis: A Cross Sectional Study. Iran J Pathol. 2025;20:33–41. doi: 10.30699/ijp.2024.2023590.3263. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 20.Ferreira Medeiros M, Jardim MR, Vital RT, et al. An Attempt to Improve Pure Neural Leprosy Diagnosis Using Immunohistochemistry Tests in Peripheral Nerve Biopsy Specimens. Appl Immunohistochem Mol Morphol. 2014;22:222–30. doi: 10.1097/PAI.0b013e31828dc70c. [DOI] [PubMed] [Google Scholar]
- 21.Duraiyan J, Govindarajan R, Kaliyappan K, et al. Applications of immunohistochemistry. J Pharm Bioallied Sci. 2012;4:S307–9. doi: 10.4103/0975-7406.100281. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 22.Oumarou Hama H, Aboudharam G, Barbieri R, et al. Immunohistochemical diagnosis of human infectious diseases: a review. Diagn Pathol . 2022;17:17. doi: 10.1186/s13000-022-01197-5. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 23.Mshana RN, Belehu A, Stoner GL, et al. Demonstration of mycobacterial antigens in leprosy tissues. Int J Lepr Other Mycobact Dis. 1982;50:1–10. [PubMed] [Google Scholar]
- 24.Govindan A, Sasidharanpillai S, Ajithkumar K, et al. Immunohistochemistry of skin lesions in leprosy and leprosy reactions. LEPROSY. 2018;89:256–71. doi: 10.47276/lr.89.3.256. [DOI] [Google Scholar]
- 25.Lastória JC, Abreu MAMM de. Leprosy: a review of laboratory and therapeutic aspects--part 2. An Bras Dermatol. 2014;89:389–401.:S0365-05962014000300389. doi: 10.1590/abd1806-4841.20142460. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 26.Verhagen C, Faber W, Klatser P, et al. Immunohistological Analysis of In Situ Expression of Mycobacterial Antigens in Skin Lesions of Leprosy Patients Across the Histopathological Spectrum. Am J Pathol. 1999;154:1793–804. doi: 10.1016/S0002-9440(10)65435-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 27.Fuertes L, Santonja C, Kutzner H, et al. Immunohistochemistry in dermatopathology: a review of the most commonly used antibodies (part I) Actas Dermosifiliogr. 2013;104:99–127. doi: 10.1016/j.ad.2012.02.015. [DOI] [PubMed] [Google Scholar]
- 28.Malhotra KP, Husain N. Laboratory perspectives for Leprosy: Diagnostic, prognostic and predictive tools. Indian J Pathol Microbiol. 2022;65:S300–9. doi: 10.4103/ijpm.ijpm_1083_21. [DOI] [PubMed] [Google Scholar]
- 29.Aromataris E, Lockwood C, Porritt K, et al., editors. JBI Manual for Evidence Synthesis. JBI; 2024. https://jbi-global-wiki.refined.site/space/MANUAL Available. [Google Scholar]
- 30.McInnes MDF, Moher D, Thombs BD, et al. Preferred Reporting Items for a Systematic Review and Meta-analysis of Diagnostic Test Accuracy Studies: The PRISMA-DTA Statement. JAMA. 2018;319:388–96. doi: 10.1001/jama.2017.19163. [DOI] [PubMed] [Google Scholar]
- 31.EQUATOR Network Enhancing the quality and transparency of health research [internet] [13-Mar-2026]. https://www.equator-network.org/ Available. Accessed.
- 32.Whiting PF, Rutjes AWS, Westwood ME, et al. QUADAS-2: a revised tool for the quality assessment of diagnostic accuracy studies. Ann Intern Med. 2011;155:529–36. doi: 10.7326/0003-4819-155-8-201110180-00009. [DOI] [PubMed] [Google Scholar]
- 33.Secretariat of Science, Technology and Strategic Inputs. Department of Science and Technology . Methodological Guidelines: Preparation of Systematic Reviews and Meta-Analyses of Diagnostic Accuracy Studies. Brasília: Ministry of Health Publishing House; 2014. p. 116. [Google Scholar]
- 34.Deeks JJ, Macaskill P, Irwig L. The performance of tests of publication bias and other sample size effects in systematic reviews of diagnostic test accuracy was assessed. J Clin Epidemiol. 2005;58:882–93. doi: 10.1016/j.jclinepi.2005.01.016. [DOI] [PubMed] [Google Scholar]
- 35.Schünemann H, Brożek J, Guyatt G, et al., editors. GRADE handbook for grading quality of evidence and strength of recommendations. Updated October 2013. The GRADE Working Group. 2013;Available from https://gdt.gradepro.org/app/handbook/handbook.html Available. [Google Scholar]
- 36.McMaster University and Evidence Prime GRADEpro gdt: gradepro guideline development tool [software] https://gdt.gradepro.org/app Available.