Quantitative Real-Time Polymerase Chain Reaction for Detection of Mycobacterium leprae DNA in Tissue Specimens from Patients with Leprosy.

In leprosy, early diagnosis is crucial to prevent transmission and onset of disabilities of the disease. The purpose of this study was to determine usefulness of quantitative real-time polymerase chain reaction (PCR) in clinically diagnosed cases of leprosy. Thirty-two leprosy cases were included. The real-time PCR was performed using commercial kit targeting Mycobacterium leprae-specific insertion sequence element. The slit skin smear was positive in two (22.2%) borderline tuberculoid (BT) patients, five (83.3%) borderline lepromatous (BL) patients, and seven (50%) lepromatous leprosy (LL). The positivity of quantitative real-time PCR in BT, BL, LL, and pure neuritic leprosy were 77.8%, 83.3%, 100%, and 33.3%, respectively. Using histopathology as the gold standard, sensitivity of quantitative real-time PCR was 93.1%, and specificity was 100%. The DNA load was higher in LL (3,854.29/106 cells), followed by BL (140.37/106 cells), and BT (2.69/106 cells). Because of the high sensitivity and specificity of real-time PCR, our study strongly suggests the use of real-time PCR as a diagnostic tool for leprosy.

Utility of Multi-target Nested PCR and ELISPOT Assays for the Detection of Paucibacillary Leprosy: A Possible Conclusion of Clinical Laboratory Misdiagnosis.

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.

Altered cytokine profiles in relapsed paucibacillary leprosy: a case report.

BACKGROUND: Individuals with relapses of leprosy should be monitored carefully, however, with respect to paucibacillary (PB) leprosy, it is sometimes difficult to make a definitive diagnosis of relapse, because the bacillary index is often negative. To evaluate the usefulness of cytokine profiling in a patient with relapsed PB leprosy who tested negative for anti-phenolic glycolipid-I antibodies, we analyzed the Mycobacterium leprae protein-induced cytokine expression in peripheral blood mononuclear cells of the patient. CASE PRESENTATION: An 89-year-old-male relapsed PB patient, first treated for leprosy over 50 years prior, was examined. In April 2012, he noticed three skin lesions consisting of annular erythema in the thighs. Slit skin smear tests were negative, and skin biopsies revealed a pathology of indeterminate-to-borderline tuberculoid leprosy. He received 600 mg of rifampicin once per month and 75 mg of dapsone daily for 12 months. The annular erythemas disappeared after starting treatment. Before treatment, and 6 and 12 months after starting treatment, the Th1/Th2 cytokine profiles in the supernatant of mononuclear cells from the patient before and after stimulation with Mycobacterium leprae soluble protein (MLS) were examined using a Cytometric Bead Array (CBA) Human Th1/Th2 Cytokine Kit II. The CBA Enhanced Sensitivity Flex Set system was applied to detect small amounts of cytokines in the serum just before treatment and one year before relapse. In the culture supernatant, just before treatment, increases in IFN-γ level and the IFN-γ/IL-10 ratio and a decreased IL-6 level were observed without stimulation. Upon stimulation with MLS, just before treatment, both the IFN-γ and TNF levels increased markedly, and twelve months after starting treatment, the IFN-γ and TNF levels decreased greatly. In the serum, just before treatment, increases in IFN-γ and TNF levels and the IFN-γ/IL-10 ratio were evident compared with those measured one year before relapse. CONCLUSIONS: Cytokine profiling using culture supernatants and serum samples may be useful for the diagnosis of relapsed PB leprosy.

Sensitivity and specificity of multibacillary and paucibacillary leprosy laboratory tests: A systematic review and meta-analysis.

This systematic review (number register: CRD42018112736) was performed to compare the sensitivity and specificity of leprosy diagnostic methods. The search was conducted in 3 electronic databases in January 2021. Studies evaluating leprosy diagnostic tests were included according the eligibility criteria. Meta-analysis was performed to calculate the sensibility and specificity of the groups. We included 36 studies. The test sensitivity for paucibacillary patients was 0.31 (95%CI: 0.29-0.33) and the specificity was 0.92 (95%CI: 0.92-0.93). In multibacillary patients, the sensitivity was 0.78 (95%CI: 0.77-0.80) and specificity was 0.92 (95%CI: 0.92-0.93). Comparing the sensitivity and specificity of the different techniques included, it should be noted that polymerase chain reaction (PCR) test presented the highest sensitivity for paucibacillary patients, while the western blot technique showed the highest sensitivity for multibacillary patients. However, further studies are needed to optimise the diagnosis of leprosy, requiring research with a larger number of samples and more uniform protocols.

Lepra tuberculoide borderline en paciente con reacción lepromatosa tipo eritema nudoso simulando un síndrome de Sweet / Borderline Tuberculoid Leprosy in Erythema Nodosum Leprosum Reaction Mimicking Sweet's Syndrome

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Indeterminate leprosy

Leprosy in its determinate from (I) is a clinical presentation of the disease preceding the forms described in the Ridley and Jopling (R & J) classification and any other special forms of leprosy or the reactions. In this chapter, the histopathological and bacilloscopic characteristics of the I form of leprosy are described, and the main differential diagnoses are discussed. The histopathological criteria that distinguish the I form from the other forms of leprosy and the reaction processes that may occur during the disease course are also discussed. The identification of the histopathological characteristics of I leprosy is of great importance with respect to the selection of the treatment. I leprosy should not be confused with other forms of leprosy, especially the multibacillary forms, wich require more prolonged treatment and wich can develop reaction phenomena, causing permanent sequelae.

Intermediate or Borderline forms (BT, BB, and BL)

Leprosy is a long-term spectrum disease and can present various clinical and histopathological aspects. Between the two poles of leprosy, there is a wide range of types, consisting of intermediate or borderline forms. In this chapter, the clinical, histopathological, and bacilloscopic characteristics of the intermediate forms (borderlibe-tuberculoid [BT], borderline-borderline [BB], and borderline lepromatous [BL]) are presented and discussed. The main clinical and pathological characteristics that allow the diagnosis and classification of leprosy among the different borderline forms are described and illustrated in panel form, as well as their most significant clinical and histopathological differential diagnoses are also discussed. The clinical-pathological classification of this disease has important implications in the choice of the correct treatment, the understanding of the pathophysiology, and the development of the reaction phenomena typical of leprosy,.

Lepra borderline tuberculoide. Presentación de un caso / No disponible

La lepra es una enfermedad no hereditaria, infectocontagiosa de evolución crónica, controlable y curable. Sin embargo, el grado de deficiencia inmunológica presente en el individuo desde su nacimiento, es lo que determina la posibilidad de enfermarse, así como la forma clínica que desarrolla el enfermo. El presente artículo describe un caso de lepra boderline tuberculoide en una paciente de 63 años, ama de casa, con lesiones en miembros inferiores y abdomen de más de dos años de evolución, constituyendo el diagnóstico de la enfermedad basados en los criterios clínicos, histopatológicos y baciloscópicos

Leprosy is a non-hereditary, infectious, chronic and curable disease. However, the degree of immunological deficiency present in the individual at birth is what determines the possibility of becoming ill, as well as the clinical form that the patient will develop. This article describes a case of tuberculoid borderline leprosy in a 63-year-old housewife with lesions in the lower limbs and abdomen of more than two years of evolution. The diagnosis of the disease was based on the clinical, histopathological and skin smear characteristics of the lesions

Lepra: a propósito de tres casos de presentación atípica / No disponible

La lepra es una enfermedad infectocontagiosa, crónica, producida por el Mycobacterium leprae. Afecta principalmente los nervios y la piel. La mayoría de las veces las lesiones son típicas y de fácil diagnóstico para los ojos entrenados de los profesionales. Sin embargo, de entre las múltiples formas clínicas, existen también lesiones de presentación muy atípicas, tanto en las formas paucibacilares como en multibacilares, dificultando el diagnóstico clínico inicial. Presentamos tres casos de lepra con manifestaciones cutáneas atípicas, 2 por la propia enfermedad y el tercero enmascarado por otra dermatosis concomitante. Los estudios histolopatológicos definieron el diagnóstico final

Leprosy is a chronic, infectious disease caused by Mycobacterium leprae. It mainly affects the nerves and the skin. Most of the time the injuries are typical and easily diagnosed by the trained eyes of professionals. However, there are also very atypical forms of presentation, both in paucibacillary and multibacillary, of difficult clinical diagnosis. Here we present three cases of atypical presentations of Hansen's disease, that required histological studies for the final and definitive diagnosis

Lazarine leprosy: A unique phenomenon of leprosy.

Leprosy, a chronic granulomatous disease, has been known since ages but even today continues to baffle the clinicians with a wide spectrum of clinical, histopathological, and immunological characteristics. Leprosy reactions are mainly of two types, namely, Type 1 and Type 2. In Type 1 leprosy reaction, the preexisting lesions become erythematous, edematous, and rarely ulcerate. Ulcerating Type 1 reaction is called lazarine leprosy. Ulcerations may occur in borderline tuberculoid (BT) pole or borderline lepromatous pole but more common in BT pole. In this postelimination era of leprosy, we report an interesting case report of BT Hansen's disease with Type 1 lepra reaction with ulceration, namely, lazarine leprosy.

Clinicobacteriological evaluation of leprosy patients with 1-5 skin lesions.

Background: Mycobacterium leprae is a noncultivable mycobacteria, and diagnosis of the disease is based on its clinical and histopathological characteristics and finding the bacteria in skin scrapings and in biopsies taken from the patients. The aim of this study was to shed light on the clinical classification (based on the number of skin lesions) used extensively in the field where patients classified as paucibacillary (PB) were positive on skin smears and histopathology leading to treatment failure and drug resistance. Methods: In this study, we enrolled untreated 62 leprosy patients with 1-5 skin lesions and did a detailed bacterio-histopathological analysis by slit-skin smears (SSSs) and histopathology. Results: Of 62 patients analyzed, 15 patients came out to be multibacillary (MB) and 47 were PB by SSS and histopathology. Conclusion: The findings of the present study showed that the WHO classification of leprosy based on the number of lesions seems to be inappropriate as it considers a number of MB lesions as PB only, thus misleading the treatment strategies. Hence, it is essential that a comprehensive clinicobacteriological assessment of leprosy cases should be done to ensure the appropriate bacillary status and guiding the appropriate treatment strategy.

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

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 (2007-2019), 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.

Lepra infantil. Presentación de tres casos / No disponible

La lepra en la infancia cursa con una diversidad de manifestaciones clínicas e histopatológicas que hacen necesario un minucioso examen cutáneo en todo niño, que presente lesiones dermatológicas sugestivas y una fuente infecciosa sospechosa. Para un oportuno diagnóstico es indispensable que el medico tenga siempre presente la enfermedad, así como la destreza al realizar el examen clínico, ya que muchas lesiones cutáneas suelen ser asintomáticas y con frecuencia simulan otros cuadros dermatológicos. El rango de edad en el cual la población infantil se encuentra más afectada está dentro de los 10 y 15 años. En la infancia la lepra refleja características clínicas del adulto, guardando ciertas particularidades; las formas paucibacilar son más comunes entre los dos y nueve años y las formas multibacilares entre los 10 a 14 años. En Cuba han sido reportados desde agosto de 1989 hasta diciembre 2016 un total de 135 casos de Lepra en pacientes en edad pediátrica de los cuales 44 (32,6 %), han sido atendidos en el Hospital Pediátrico Docente Juan Manuel Márquez. OBJETIVO: presentación clínica de tres casos de lepra infantil con formas clínicas diferentes. CONCLUSIONES: La lepra en la infancia cursa con una diversidad de manifestaciones clínicas e histopatológicas, que hacen necesario un minucioso examen cutáneo en todo nino, que presente lesiones dermatológicas sugestivas y una fuente infecciosa sospechosa. El mayor énfasis en la detección y vigilancia temprana de esta enfermedad se debe a que alguno de los niños que recientemente han sido diagnosticados ya mostraban signos de discapacidad

Leprosy in childhood presents a variety of clinical and histopathological manifestations that require a thorough skin examination in every child, presenting suggestive dermatological lesions and a suspicious infectious source. For a timely diagnosis it is essential that the doctor always keeps in mind the disease, as well as the knowledge for performing the clinical examination, since many skin lesions are usually asymptomatic and often simulate other dermatological conditions. The age range in which children are most affected is most affected is within 10 and 15 years. In childhood, leprosy reflects the clinical characteristics of the adult, keeping certain peculiarities; paucibacillary forms are more common between two and nine years old and multibacillary forms between 10 and 14 years old. In Cuba, a total of 135 cases of leprosy have been reported from August 1989 to December 2016 in pediatric patients, of which 44 (32.6%) have been treated at the Juan Manuel Marquez Teaching Pediatric Hospital. OBJECTIVE: clinical presentation of three cases of childhood leprosy with different clinical forms. CONCLUSIONS: Childhood leprosy has a variety of clinical and histopathological manifestations, which require a thorough skin examination in every child, presenting suggestive dermatological lesions and a suspicious infectious source. The greatest emphasis on the detection and early surveillance of this disease is due to the fact that some of the children who have recently been diagnosed already showed signs of disability

Development of LepReact, a defined skin test for paucibacillary leprosy and low-level M. leprae infection.

The persistence of new leprosy cases in endemic areas such as India, Brazil, Bangladesh, and the Philippines has encouraged studies of chemoprophylaxis among contacts of patients. Epidemiological screening tools to enable early detection of infected individuals in endemic populations would be critical to target individuals most in need of intervention. Despite decades of attempts, however, there still are no tests available for the early detection of low-level infection with Mycobacterium leprae. In this report, we describe the development of a leprosy skin test using M. leprae-specific antigens. We selected the chimeric LID-1 fusion protein, formulated to achieve maximum performance at a minimal dose, as a skin test candidate based on its ability to elicit delayed-type hypersensitivity (DTH) reactions in M. leprae immune guinea pigs in a sensitive and specific manner, i.e., with no cross-reactivity observed with other mycobacterial species. Importantly, evaluations in armadillos indicated that intradermal inoculation of formulated LID-1 could distinguish uninfected from M. leprae-infected animals manifesting with symptoms distinctly similar to the PB presentation of patients. Together, our data provide strong proof-of-concept for developing an antigen-specific skin test to detect low-level M. leprae infection. Such a test could, when applied with appropriate use of chemo- and/or immunoprophylaxis, be instrumental in altering the evolution of clinical disease and M. leprae transmission, thus furthering the objective of zero leprosy.

Comparison of quality of life evaluated by SF-36 and DLQI in multibacillary and paucibacillary leprosy patients from Sao Paulo, Brazil.

BACKGROUND: Dermatological diseases have a negative impact on quality of life (QoL), affecting mental and physical health. Leprosy patients usually present with a worse QoL compared with those affected by other conditions. Reactions, neural damage, and pain are some of the consequences that contribute to the lower QoL. However, due to the wide spectrum of the disease, symptoms vary according to leprosy's subtype. This study aimed to compare the QoL between paucibacillary and multibacillary leprosy patients. Individuals were also compared considering the presence of reactions and a correlation between questionnaires was performed. METHODS: A total of 104 patients with leprosy aged 18 years old and over were selected. QoL was assessed by the Brazilian-Portuguese validated versions of the Medical Outcomes Study 36-item short-form health survey (SF-36) and the Dermatology Life Quality Life Index (DLQI). RESULTS: Multibacillary patients showed a more impaired physical function, worse bodily pain, lower score of SF-36, and higher interference of skin on the performance of daily activities when compared to the paucibacillary group. Individuals without reactions presented lower bodily pain and less effect of the skin on clothing choices compared to those with reactions. The SF-36 domains exhibited weak correlations with most DLQI questions, and the linear regression model showed that 32% of changes in QoL were related to the skin aspect. CONCLUSIONS: Multibacillary leprosy patients have a worse QoL when compared to paucibacillary patients. Reactions played a small role in the QoL of our cohort of patients.

Host immune responses induced by specific Mycobacterium leprae antigens in an overnight whole-blood assay correlate with the diagnosis of paucibacillary leprosy patients in China.

BACKGROUND: Leprosy, caused by Mycobacterium leprae, affects over 200,000 people annually worldwide and remains endemic in the ethnically diverse, mountainous and underdeveloped southwestern provinces of China. Delayed diagnosis of leprosy persists in China, thus, additional knowledge to support early diagnosis, especially early diagnosis of paucibacillary (PB) patients, based on the host immune responses induced by specific M. leprae antigens is needed. The current study aimed to investigate leprosy patients and controls in Southwest China by comparing supernatants after stimulation with specific M. leprae antigens in an overnight whole-blood assay (WBA) to determine whether host markers induced by specific M. leprae antigens improve the diagnosis or discrimination of PB patients with leprosy. METHODOLOGY/PRINCIPAL FINDINGS: Leprosy patients [13 multibacillary (MB) patients and 7 PB patients] and nonleprosy controls [21 healthy household contacts (HHCs), 20 endemic controls (ECs) and 19 tuberculosis (TB) patients] were enrolled in this study. The supernatant levels of ten host markers stimulated by specific M. leprae antigens were evaluated by overnight WBA and multiplex Luminex assays. The diagnostic value in PB patients and ECs and the discriminatory value between PB patients and HHCs or TB patients were evaluated by receiver operator characteristics (ROC) analysis. ML2044-stimulated CXCL8/IL-8 achieved the highest sensitivity of 100%, with a specificity of 73.68%, for PB diagnosis. Compared to single markers, a 3-marker combination model that included ML2044-induced CXCL8/IL-8, CCL4/MIP-1 beta, and IL-6 improved the diagnostic specificity to 94.7% for PB patients. ML2044-stimulated IL-4 and CXCL8/IL-8 achieved the highest sensitivity (85.71% and 100%) and the highest specificity (95.24% and 84.21%) for discriminating PB patients from HHCs and TB patients, respectively. CONCLUSIONS: Our findings suggest that the host markers induced by specific M. leprae antigens in an overnight WBA increase diagnostic and discriminatory value in PB patients with leprosy, with a particularly strong association with interleukin 8.

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

OBJECTIVE: The 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. METHODS: One 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. RESULTS: In 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. CONCLUSION: The use of qPCR in suspected PB cases with an inconclusive histology improved the sensitivity of leprosy diagnoses.

Development and evaluation of a droplet digital PCR assay for the diagnosis of paucibacillary leprosy in skin biopsy specimens.

BACKGROUND: The reduced amounts of Mycobacterium leprae (M. leprae) among paucibacillary (PB) patients reflect the need to further optimize methods for leprosy diagnosis. An increasing number of reports have shown that droplet digital polymerase chain reaction (ddPCR) is a promising tool for diagnosis of infectious disease among samples with low copy number. To date, no publications have investigated the utility of ddPCR in the detection of M. leprae. The aim of this study was to develop and evaluate a ddPCR assay for the diagnosis of PB leprosy. METHODOLOGY: The two most sensitive DNA targets for detection of M. leprae were selected from electronic databases for assessment of sensitivity and specificity by quantitative polymerase chain reaction (qPCR) and ddPCR. Control patients (n = 59) suffering from other dermatological diseases were used to define the cut-off of the duplex ddPCR assay. For comparative evaluation, qPCR and ddPCR assays were performed in 44 PB patients and 68 multibacillary (MB) patients. PRINCIPAL FINDINGS: M. leprae-specific repetitive element (RLEP) and groEL (encoding the 65 kDa molecular chaperone GroEL) were used to develop the ddPCR assay by systematically analyzing specificity and sensitivity. Based on the defined cut-off value, the ddPCR assay showed greater sensitivity in detecting M. leprae DNA in PB patients compared with qPCR (79.5% vs 36.4%), while both assays have a 100% sensitivity in MB patients. CONCLUSIONS/SIGNIFICANCE: We developed and evaluated a duplex ddPCR assay for leprosy diagnosis in skin biopsy samples from leprosy patients. While still costly, ddPCR might be a promising diagnostic tool for detection of PB leprosy.