Role of histopathological, serological and molecular findings for the early diagnosis of treatment failure in leprosy.

BACKGROUND: Treatment failure (TF) in leprosy following multidrug therapy (MDT) presents a significant challenge. The current World Health Organization (WHO) fixed-duration MDT regimen, based on lesion count, might not be adequate. Leprosy lacks clear-cut objective cure criteria, and the predictive value of post-MDT histopathological findings remains uncertain. This study aims to identify predictive factors for TF among leprosy patients who have completed the WHO-recommended MDT. METHODS: An analysis was conducted on 80 individuals from a national leprosy reference center, comprising 40 TF cases (with a mean relapse at 13.0 months) and 40 controls (with a mean of 113.1 months without disease signs). Various epidemiological and clinical-laboratory parameters were assessed post-MDT. RESULTS: In skin samples, the presence of foamy granuloma (OR = 7.36; 95%CI2.20-24.60; p = 0.0012) and histological bacillary index (hBI) ≥ 1+ (OR = 1.55; 95%CI1. 22-1.99; p = 0.0004) were significantly associated with TF, with odds ratios of 7.36 and 1.55, respectively. Individuals who experienced TF had a mean hBI of 3.02+ (SD ± 2.02), while the control group exhibited a mean hBI of 1.8+ (SD ± 1.88). An hBI ≥ 3 + showed a sensitivity of 73% and a specificity of 78% for TF detection (AUC: 0.75; p = 0.0001). Other histopathological features like epithelioid granulomas, and skin changes did not show significant associations (p > 0.05). Additionally, higher anti-phenolic glycolipid-I (anti-PGL-I) ELISA index (EI) levels were linked to a 1.4-fold increased likelihood for TF (OR = 1.4; 95%CI1.13-1.74; p = 0.0019). A mean EI of 4.48 (SD ± 2.80) was observed, with an EI ≥ 3.95 showing a sensitivity of 79% and a specificity of 59% for TF detection (AUC: 0.74; p = 0.0001). Moreover, the presence of Mycobacterium leprae (M. leprae) DNA in real-time polymerase chain reaction (qPCR) was associated with a 3.43-fold higher likelihood of TF. Multivariate regression analysis indicated that concurrent presentation of neural/perineural lymphocytic infiltrate, foamy granuloma, hBI ≥ 1+, and EI ≥ 1 markedly increased the likelihood of TF by up to 95.41%. CONCLUSION: Persistence of nerve-selective lymphocytic infiltrate, foamy granulomas, and bacilli in skin biopsies, and elevated EI post-MDT, may serve as predictive factors for identifying individuals at higher probability of TF.

Mycobacterium leprae and Mycobacterium lepromatosis in small mammals in Midwest Brazil.

Leprosy is a chronic infectious disease caused by the bacilli Mycobacterium leprae and Mycobacterium lepromatosis. In addition to humans, animals such as nine-banded armadillos and red squirrels are species naturally infected. The objective of this study was to investigate the presence of M. leprae and M. lepromatosis in non-volant small mammals of the order Didelphimorphia and Rodentia through Polymerase Chain Reaction (PCR) assay. During 2015 and 2018, field expeditions were carried out in three municipalities, covering biotic elements of the Amazon and Cerrado biomes, in the Mato Grosso State, Midwest of Brazil. A specific primer for repetitive sequences of the genomic DNA of M. leprae and M. lepromatosis targeting the RLEP and RLPM gene, respectively, was used to screen for these agents. The molecular detection of M. leprae DNA in the samples was 13.8%. M. lepromatosis was not detected. The present study reports a description of M. leprae in small non-volant mammals in Brazil.

Molecular Identification of Mycobacterium leprae in the Leprosy Patients.

BACKGROUND: Several discoveries about leprosy indicate that Mycobacterium leprae transmission mainly occurs by inhalation, and the nose is a major port of entry and exit. Molecular probes have shown certain potential for the detection and identification of M. leprae in patients. The aim of this study was to identify M. leprae in nasal swab specimens using polymerase chain reaction (PCR)-based assays followed by gene sequencing methods. This observational study examines 64 anterior nasal swab samples taken from pretreatment leprosy patients, on-treatment and completed leprosy treatment in Bulukumba, South Sulawesi, Indonesia. METHODS: samples were analyzed by molecular detection methods according to the standard methods at the Clinical Microbiology Laboratory of Hasanuddin University. Descriptive statistics were utilized to summarize patient demographics and outcomes. RESULTS: This study uses PCR to detect the M. leprae deoxyribonucleic acid (DNA) from nasal swab specimens. Data were collected from 64 patients with a percentage of male patients 51.54%. Based on the age category, the group 45-46 years was the most frequent (39.05%). PCR detection proline-rich antigen gene of a 531 bp DNA fragment from M. leprae, was positive in eight patients, and they were multibacillary. Furthermore, PCR was positive in 5 (31.25%) of 16 new leprosy patients, 2 (8.69%) of 23 on-treatment patients, and 1 (4%) of 25 treatment completed patients. Based on the results of the phylogenetic tree and analysis of 8 positive results detected by M. leprae from leprosy patients, almost all samples have a level of similarity, except for sample Ua7. CONCLUSIONS: M. leprae cannot grow in vitro, so molecular diagnostic tools were used to confirm the disease. This study predominantly of males with the age above 45 years of age being the most common. Eight M. leprae were positive from nasal swab leprosy patients. The sequencing findings provide insight into the genetic diversity of the genus M. leprae, so it is necessary to consider the detection of whole-genome sequence.

Pure neuritic leprosy: Latest advancements and diagnostic modalities: Diagnosis of Pure Neuritic Leprosy.

Pure neuritic leprosy (PNL) is characterized by exclusive peripheral neuropathy without dermatological alterations. Diagnosis is difficult since skin lesions and acid-fast bacilli (AFB) in slit smears are absent. Presently, the gold standard for diagnosis is the histopathological examination of peripheral nerve biopsy. Even then, the detection of bacteria is difficult, and histological findings may be non-specific. Nerve biopsy is an invasive procedure that is possible only in specialized centers and limited to certain sensory nerves. Therefore, the establishment of serological, immunological, and molecular laboratory tests could be more beneficial for diagnosing pure neuritic leprosy to achieve effective treatment and reduction in its consequent disabilities. This review suggests that the presence of Mycobacterium leprae (M.leprae) in PNL cases can be proven by using non-invasive procedures, viz., multiplex polymerase chain reaction (M-PCR), serological findings, immunological profiling, and improved nerve-imaging. Findings also indicate the necessity for improving the sensitivity of PCR and further research on specificity in ruling out other clinical conditions that may mimic PNL.

Diagnostic Utility of Multiplex Polymerase Chain Reaction in Patients of Clinically Suspected Pure Neuritic Leprosy by Identifying Mycobacterium leprae in Skin Biopsy Samples and Nasal Swabs.

Pure neuritic leprosy (PNL) often remains underdiagnosed due to the lack of simple, reliable diagnostic tools to detect Mycobacterium leprae. This study aimed to investigate the utility of multiplex polymerase chain reaction (MPCR) in easily accessible and less invasive biopsy sites, including skin biopsy samples and nasal swabs (NSs), to detect M. leprae. A total of 30 (N = 30) clinically suspected and untreated patients with PNL were recruited. Nasal swabs and skin biopsy samples from the innervation territory of an "enlarged nerve" were collected. DNA was extracted and subjected to MPCR (targeting leprae-specific repetitive element [RLEP], 16S rRNA, and SodA genes) and RLEP-PCR (individual gene PCR). The PCR products were analyzed by 3% agarose gel electrophoresis. In 30 patients with clinically suspected PNL, 60% (N = 18) of skin biopsy samples and 53% (N = 16) of NSs were found positive for M. leprae DNA by MPCR, whereas only 23.3% (N = 7) of skin biopsy samples and 10% (N = 3) of NSs were found positive by RLEP-PCR. MPCR demonstrated a greater positivity rate than did RLEP-PCR for detection of M. leprae. Serologic positivity for anti-natural disaccharide-octyl conjugated with bovine serum albumin (ND-O-BSA) antibodies was 80% (16/20), including 35% (7/20) of PNL patients for which the skin MPCR was negative. Both serologic positivity and skin MPCR positivity were observed in 65% of patients (N = 20). Multiplex polymerase chain reaction is a useful tool for detection for M. leprae in skin biopsy samples and NSs in clinically suspected cases of PNL, with the added advantages of being less invasive and technically easier than nerve biopsy.

A case report and literature review: Mycobacterium leprae infection diagnosed by metagenomic next-generation sequencing of cerebrospinal fluid.

BACKGROUND: Leprosy is a chronic infectious disease caused by Mycobacterium leprae (M. leprae) that is responsible for deformities and irreversible peripheral nerve damage and has a broad spectrum of clinical and serological manifestations. Leprosy primarily affects the peripheral nerves and rarely presents with central nervous system involvement. Diagnosing leprosy can still be difficult in some cases, especially when the infection involves uncommon clinical manifestations and extracutaneous sites. Delayed diagnosis and treatment of leprosy may lead to irreversible damage and death. CASE PRESENTATION: We report a case of a 30-year-old female presenting with "repeated high fever with symptoms of headache for 14 days". On the day of admission, physical signs of lost eyebrows and scattered red induration patches all over her body were observed. The patient's diagnosis was based on the clinical characteristics using a combination of metagenomic next-generation sequencing (mNGS) of cerebrospinal fluid (CSF) and slit-skin smear. After confirming Listeria meningitis and multibacillary leprosy with erythema nodosum leprosum (ENL), a type 2 reaction, she was treated with ampicillin sodium, dapsone, rifampicin, clofazimine, methylprednisolone, and thalidomide. At the 1-year follow-up, the frequency and severity of headaches have significantly decreased and a good clinical response with improved skin lesions was found. CONCLUSION: This case highlights the importance of considering leprosy, which is a rare and underrecognized disease, in the differential diagnosis of skin rashes with rheumatic manifestations, even in areas where the disease is not endemic, and physicians should be alerted about the possibility of central nervous system infections. In addition, mNGS can be used as a complementary diagnostic tool to traditional diagnostic methods to enhance the diagnostic accuracy of leprosy.

Systemic Lupus Erythematosus Complicated with Mycobacterium Leprae Infection: a Rare Case Report.

BACKGROUND: In December 2023, our hospital confirmed a case of systemic lupus erythematosus complicated with Mycobacterium leprae infection. The patient has extensive patchy erythema on the back and face, with obvious itching. There are multiple subcutaneous masses on both hands, some of which are accompanied by tenderness, wave sensation, and other symptoms. The patient's mother has a history of leprosy and close contact with the patient. The patient tested positive for syphilis antibodies 2 years ago and did not receive formal treatment. There is no other history of chronic illness. METHODS: Under local anesthesia, the left hand skin lesion was excised, followed by tissue pathological biopsy, acid-fast staining, mNGS, and serum Treponema pallidum antibody detection. RESULTS: Pathological biopsy results: A large number of foam-like histiocytes, lymphocytes, and plasma cells were mainly found in the superficial and deep layers of the dermis, as well as around the blood vessels and sweat glands in the subcutaneous fat. Cellulose-like degeneration is seen in some blood vessel walls. Tissue acid-fast staining: positive, tissue mNGS detection: Mycobacterium leprae. CLINICAL DIAGNOSIS: 1. Borderline leprosy, 2. Subacute cutaneous lupus erythematosus. Treat with methylprednisolone 32 mg qd po + aluminum magnesium suspension 15 mL tid po + calcium carbonate D3 tablets 0.6 g qd po + rifampicin 450 mg qd po + dapsone 100 mg qd. After 10 days of treatment, the patient improved and was discharged from the hospital. CONCLUSIONS: Mycobacterium leprae infection occurs during SLE treatment and is often difficult to distinguish from skin symptoms caused by SLE. In the clinical treatment of infectious diseases, the effect of conventional anti-bacterial drugs is not good. The auxiliary examination indicates severe infection and the routine culture is negative. The possibility of special pathogen infection should be considered in combination with the medical history. With the popularity of new detection methods such as mNGS, the importance of traditional smear detection methods cannot be ignored.

A case report of de novo histoid leprosy in a Nigerian male: A diagnostic dilemma.

Histoid leprosy is an uncommon variant of lepromatous leprosy. It poses a diagnostic challenge because of its distinctive clinical and histopathological features. It presents as smooth papules and nodules that rarely ulcerate. We present the case of a 22-year-old Nigerian man with a 2-year history of multiple, dome-shaped papules and nodules on the skin with necrotic centres. General examination showed right axillary lymphadenopathy, non-pitting oedema, foot ulcer, and glove and stocking sensation loss. Despite previous misdiagnoses, histopathological examination showed dermal expansion by histiocytes arranged in a storiform pattern. Slit skin smear yielded abundant bacilli. The patient was started on WHO multidrug treatment, resulting in the improvement of his lesions. This case emphasises the importance of increased awareness of this rare presentation of leprosy.

Prevalence of Mycobacterium leprae and Mycobacterium lepromatosis in roadkill armadillos in Brazil.

To evaluate the prevalence of Mycobacterium leprae and Mycobacterium lepromatosis in road killed armadillos identified along Brazilian regions, samples of liver, spleen, muscle, ear, nose and tail were collected on highways from 78 animals. The armadillos were of four different species, Cabassous tatouay, Dasypus novemcinctus, Dasypus septemcinctus and Euphractus sexcinctus. After DNA extraction from two tissues, specific primers were used for the detection of each pathogen using SYBR green qualitative Real-Time PCR, and amplicons were sequenced. The species with the highest prevalence was D. novemcinctus, mainly in the Central-West, South, and Southeast regions of Brazil. We detected M. leprae DNA in 32 (41 %) of the 78 individuals and M. lepromatosis DNA was not identified in any of the examined samples. The zoonotic component of leprosy may play a role in the transmission of the disease in endemic areas in which environmental conditions and contact with reservoirs must be investigated.

Leprosy Presenting as Distal Acquired Demyelinating Symmetric Variant of Chronic Inflammatory Demyelinating Polyneuropathy: An Atypical Manifestation of Hansan's Disease.

Leprosy, caused by the bacterium Mycobacterium leprae, is known to primarily affect the skin and peripheral nerves. We present a rare case of leprosy initially manifesting as demyelinating polyneuropathy. A 46-year-old female presented with progressive weakness, tingling, and numbness in her extremities. Nerve conduction studies revealed evidence of demyelination, prompting further investigations. Skin slit-skin smears confirmed the diagnosis of leprosy, with the presence of acid-fast bacilli. The patient was subsequently started on multidrug therapy, leading to significant clinical improvement. This case highlights the importance of considering leprosy as a differential diagnosis in patients presenting with demyelinating polyneuropathy, especially in endemic regions.

Molecular and spatial evaluation of small rodents and Didelphimorphis infected with Mycobacterium leprae in the southern Amazon, Brazil.

BACKGROUND: The high levels of recent transmission of leprosy worldwide demonstrate the necessity of epidemiologic surveillance to understand and control its dissemination. Brazil remains the second in number of cases around the world, indicating active transmission of Mycobacterium leprae (M. leprae) in the population. At this moment, there is a consensus that the bacillus is transmitted by inter-human contact, however, different serologic, molecular, and histopathological approaches indicate the existence of non-human transmission sources. METHODS AND RESULTS: The qPCR assay was used to amplify the molecular targets 16S RNAr and RLEP, in samples of liver, spleen, and ear of wild animals belonging to Didelphimorphia and Rodentia orders, in highly endemic areas of Mato Grosso, Brazil. The RLEP repetitive sequence was positive in 202 (89.0%) samples, with 96 (42.3%) of these also being positive for the 16S gene. Regarding the collection sites, it was observed that the animals were found in areas profoundly deforested, close to urban areas. CONCLUSIONS: Our results suggest that wild animals can play an important role in the maintenance of M. leprae in endemic regions with major anthropic action in Brazil. Therefore, integrating human, animal, and environmental health care with the One Health initiative is highly efficient for the development of effective strategies to contain and control leprosy in Brazil.

Comparative Evaluation of Multiplex PCR, RLEP PCR and LAMP PCR in Urine, Stool and Blood Samples for the Diagnosis of Pediatric Leprosy - A Cross-Sectional Study.

OBJECTIVE: To compare the diagnostic efficacy of multiplex polymerase chain reaction (PCR), Mycobacterium leprae-specific repetitive element (RLEP) PCR and loop-mediated isothermal amplification (LAMP) PCR in the diagnosis of pediatric leprosy as an alternative to slit-skin smear (SSS) examination. METHODS: A cross-sectional study was performed on 26 children aged 0-18 years with characteristic skin lesions of leprosy. SSS examination for acid fast bacilli (AFB) was performed for all children. Additionally, urine, stool and blood samples were tested by three PCR techniques - multiplex, RLEP and LAMP. The results of these tests were compared with each other and with results of SSS examination for acid fast bacilli (AFB) using appropriate statistical tests. RESULTS: Out of 26 patients studied, SSS examination was positive for AFB in 7 cases (26.9%). In blood samples, the positivity of multiplex PCR, RLEP PCR and LAMP PCR was 84.6%, 80.8%, and 80.8%, respectively. Multiplex PCR in blood samples was positive in 100% (n = 7) of SSS positive cases and 84.2% (16 out of 19) of the SSS negative cases (P < 0.001). The positivity of all PCR methods in urine and stool samples was significantly lesser than in blood. CONCLUSION: Multiplex PCR in blood sample is a superior diagnostic tool for pediatric leprosy compared to RLEP PCR and LAMP PCR as well as SSS examination.

A Case of Lepromatous Leprosy (Lucio's Phenomenon) Presenting as Periorbital Edema.

Despite low prevalence of leprosy worldwide, new cases continue to present and require swift evaluation and diagnosis to prevent complications. Here, we describe a case of lepromatous leprosy with Lucio's phenomenon initially presenting with facial and periorbital edema. A 38-year-old Brazilian woman presented to the emergency department with facial swelling and erythema, initially treated as cellulitis. Due to rapid worsening despite broad-spectrum antibiotics, she underwent soft tissue exploration and biopsy due to concern for necrotizing fasciitis. During her course, she also developed retiform purpura of bilateral upper and lower extremities. Periorbital and lower extremity pathological specimens ultimately revealed acid-fast bacilli consistent with Mycobacterium leprae , and the patient improved with multidrug therapy. This case illustrates the diagnostic difficulty of lepromatous leprosy with Lucio's phenomenon, which can initially present with periorbital edema.

Ancient Mycobacterium leprae genome reveals medieval English red squirrels as animal leprosy host.

Leprosy, one of the oldest recorded diseases in human history, remains prevalent in Asia, Africa, and South America, with over 200,000 cases every year.1,2 Although ancient DNA (aDNA) approaches on the major causative agent, Mycobacterium leprae, have elucidated the disease's evolutionary history,3,4,5 the role of animal hosts and interspecies transmission in the past remains unexplored. Research has uncovered relationships between medieval strains isolated from archaeological human remains and modern animal hosts such as the red squirrel in England.6,7 However, the time frame, distribution, and direction of transmissions remains unknown. Here, we studied 25 human and 12 squirrel samples from two archaeological sites in Winchester, a medieval English city well known for its leprosarium and connections to the fur trade. We reconstructed four medieval M. leprae genomes, including one from a red squirrel, at a 2.2-fold average coverage. Our analysis revealed a phylogenetic placement of all strains on branch 3 as well as a close relationship between the squirrel strain and one newly reconstructed medieval human strain. In particular, the medieval squirrel strain is more closely related to some medieval human strains from Winchester than to modern red squirrel strains from England, indicating a yet-undetected circulation of M. leprae in non-human hosts in the Middle Ages. Our study represents the first One Health approach for M. leprae in archaeology, which is centered around a medieval animal host strain, and highlights the future capability of such approaches to understand the disease's zoonotic past and current potential.

Case Report: Lepromatous Leprosy and Psoriasis: An Uncommon Coincidence.

Leprosy, a chronic infectious disease, and psoriasis, an inflammatory disorder, are distinct entities. Epidemiology data show that these two diseases are almost mutually exclusive, with only a few reported cases of their coexistence. Here, we present the case of a patient manifesting intermingled psoriatic and leprosy lesions diagnosed as borderline lepromatous leprosy and plaque psoriasis. Of note, Mycobacterium leprae bacilli were detected not only in the two types of lesions but also in normal-appearing skin and blood.

Leprosy in the Heartland.

BACKGROUND: Mycobacterium leprae is an acid fast bacterium that causes leprosy, also known as Hansen's disease. M. leprae spreads primarily through respiratory droplets and skin contact, and widespread migration of the human population may lead to infection in non-endemic areas. Leprosy mainly affects the skin, peripheral nerves, mucosa of the upper respiratory tract, and the eyes, presenting as a spectrum of disease based on the host immune response consisting of skin lesions, areas of anesthesia, local tissue destruction, and even blindness or glomerulonephritis in severe cases. CASE DESCRIPTION: We describe a case of leprosy presenting in a South Dakota resident. Before this case, leprosy had not been reported in South Dakota in 11 years. The patient presented with chronic skin lesions with areas of anesthesia on her right knee and left elbow. Physical exam was unremarkable aside from the skin lesions, which had areas of decreased sensation over the involved skin. Biopsy of the lesions was positive for noncaseating granulomas with lymphocytic infiltrate that were acid-fast bacillus positive. The biopsy was sent to the National Hansen's Disease Program for further molecular testing, which confirmed M. leprae infection. The patient underwent 12 months of dapsone 100 mg po qd and rifampin 600 mg po qd per U.S. guidelines from the National Hansen's Disease Program Clinical Center. The patient responded well to treatment until developing a reversal reaction after nine months, which was resolved with corticosteroid treatment. Both dermatology and infectious disease continue to follow the patient, and she continues to do well with no evidence of recurrence of active infection or evidence of reversal reaction. CONCLUSIONS: It is important that clinicians be aware of the possibility of uncommon presentations/diseases such as leprosy in areas where it is extremely rare (such as South Dakota) due to immigration and travel among patients. The rarity of leprosy in areas like South Dakota, in addition to its potential for misdiagnosis, may lead to delay of treatment in the patient. Delays in treatment can allow progression of the disease causing skin lesions and possible nerve damage.