Expression of cyclooxygenase type 2 in lepromatous and tuberculoid leprosy lesions

BACKGROUND

Leprosy is an infectious disease with two polar forms, tuberculoid leprosy (TL) and lepromatous leprosy (LL), which are dominated by T-helper (Th) 1 and Th2 cells, respectively. High concentrations of prostaglandin E2 produced by the inducible enzyme cyclooxygenase type 2 (COX-2) in LL could inhibit Th1 cytokine production, contributing to T-cell anergy.

OBJECTIVES

To compare the COX-2 expression in LL and TL.

METHODS

Skin biopsies from 40 leprosy patients (LL, n = 20; TL, n = 20) were used to determine by immunohistochemistry and automated morphometry the percentage of COX-2 immunostained cells.

RESULTS

Most COX-2-positive cells were macrophages; their percentages in the inflammatory infiltrate located in the papillary dermis, reticular dermis and periadnexally were significantly higher in LL than TL (P < 0.001 by Student's t-test).

CONCLUSIONS

The high expression of COX-2 in LL may be related to high prostaglandin production contributing to T-cell anergy.

Erythema nodosum leprosum and orbital involvement

This is the first report of ENL involving the orbit in a lepromatous patients with recurrent ENL, receiving MDT. Severe injury to the eye ensued, in spite of continued ENL and appropriate treatment of the reaction.

[Histoid leprosy with erythema nodosum leprosum]

Histoid leprosy is a particular variant of lepromatous leprosy presenting as cutaneous or subcutaneous nodular and/or plaque-like lesions arising form apparently normal skin. It is characterized histologically by spindle-shaped histiocytes in interlacing bundles and whorls, containing numerous intact and rod-shaped Mycobacterium leprae. It can occur de novo or secondary in patients treated for a long course by dapsone alone. We describe a case of lepromatous leprosy treated according to the national Moroccan protocol who developed histoid lesions during his treatment by dapsone. The patient responded well to fluoroquinolone, rifampicin and clofazimine, with however, the occurrence of erythema nodosum leprosum.

Ultrastructural Study of Schwann Cells and Endothelial Cells in the Pathogenesis of Leprous Neuropathy

Peripheral nerve biopsies from 4 borderline tuberculoid (BT) and 4 lepromatous (LL) patients who were on multidrug therapy were investigated by light and electron microscopic studies. The variation of diameters and distribution of myelinated and unmyelinated fibers between BT and LL patients were not significant. This study has shown significant changes in peripheral nerves and endoneural blood vessels. It was revealed that besides Schwann cells (SC), the endothelial cells (EC) of endoneural blood vessels frequently harbor M. leprae. In BT, peripheral nerves in addition to the degenerative changes of SC and presence of perineural and perivascular cuffing by mononuclear cells, the endoneurial blood vessels showed thickening of basement membrane with hypertrophy of EC leading to narrowing or complete occlusion of lumen. On the other hand, peripheral nerves of LL patients were infiltrated with large number of M. leprae shown to be present in the electron transparent zone (ETZ) of the SC. The EC of endoneurial blood vessels were found to be loaded with M. leprae, and this bacillary loaded EC was found to release M. leprae into the lumen through its ruptured membrane.

Molluscum contagiosum-like lesions in lepromatous leprosy

A 23-year old male presented with multiple, asymptomatic, raised lesions of 4 months' duration. The lesions were well demarcated. Dome-shaped papules and nodules were seen on normal looking skin; some were shiny, pearly white and umbilicated. Bilateral greater auricular, ulnar, radial cutaneous and lateral popliteal nerves were thickened. Slit skin smear from an umbilicated nodule had a BI of 6+. Biopsy showed features of lepromatous leprosy.

Nodular Leprosy of Childhood and Tuberculoid Leprosy: A Comparative, Morphologic, Immunopathologic and Quantitative Study of Skin Tissue Reaction

Nodular leprosy of childhood (NL) is a benign clinical variant of tuberculoid leprosy that affects breast-feeding infants and children that remained in a highly infected environment. The lesions resolve with complete healing and NL has been considered a manifestation of allergy and congenital immunity to Mycobacteria leprae. We studied the tissue reaction, Mycobacterial antigen frequency, and the lymphocyte subsets (CD45RO+, CD4+, CD8+, B, NK), dendritic cells (epidermal CD1a+ cells and S100+ dermal dendrocytes), and macrophages in skin lesions of a clinically well characterized NL group (N = 11). Results were compared to children (N = 23) and adults (N = 24) with classical tuberculoid leprosy. NL lesion histopathology was characterized by dense granulomatous inflammatory reaction, with a greater number of confluent tubercles when compared to the other groups. Neural compromise was seen in all biopsies. The frequency of Mycobacterium antigen was similar in all groups. The population of CD45RO+, CD4+ and CD8+ T lymphocytes, natural killer cells, B lymphocytes, CD1a+ epidermal cells, and macrophages of NL lesions did not differ from the other groups. The number of S100+ dermal dendritic cells of the NL group was smaller than that of the adult group, although it did not differ from the other group of children. Except for the confluent tubercules, our data could not disclose any other difference in the tissue reaction of NL, in spite of its peculiar clinical features and evolution when compared with the classical tuberculoid leprosy. The localization of NL lesions may be the result of the intimate skin contact with lepromatous parents or relatives, in areas such as cheeks, arms, buttocks, and limbs, and the innoculation of M. leprae into skin may strongly stimulate cell mediated immunity (CMI) against the bacilli. These circumstances might explain the good CMI response leading to high resistance, stability, and auto-resolution of nodular leprosy of childhood.

Pentoxifylline in the treatment of erythema nodosum leprosum

Erythema nodosum leprosum (ENL) is a well-known serious complication affecting 10% of lepromatous multibacillary leprosy patients. In the chronic form, its morbidity may be considerable. Thalidomide and systemic steroids are the two current effective drugs for the management of ENL. However, their use in endemic countries is often difficult and hazardous, and a search for new therapies is needed. We report our experience on the effects of pentoxifylline, a methylxanthine derivative, which has recently been suggested as a possible effective treatment for ENL attacks.

Relapse of lepromatous leprosy after WHO/MDT with rapid bacterial growth

The authors report a case of relapse in a lepromatous patient 6 years after he had been cured by MDT/WHO/24 doses. The atypical aspect emphasized in this case is the bacterial load increase in a short period of time of 1 year after the smear count was negative, and the case reinforces the importance of patient education on release. No leprosy cases were identified in the patient's close contacts. It seems that relapse was a result of bacillary persistence, since a significant improvement was noted in relapsed lesions after two doses of MDT/WHO.

Thalidomide in the treatment of leprosy

Leprosy is a chronic infection of the skin and nerves caused by Mycobacterium leprae. Erythema nodosum leprosum (ENL) is a reactive state in lepromatous leprosy. Thalidomide has been used to treat ENL since the 1960s. One of its mechanisms of action is anti-inflammatory through selective inhibition of the pro-inflammatory cytokine TNF-alpha produced by monocytes.

Mycobacterium leprae and leprosy: a compendium

Leprosy is a chronic infectious disease caused by Mycobacterium leprae, which was discovered by G.H.A. Hansen in 1873. M. leprae is an exceptional bacterium because of its long generation time and no growth in artificial media. Entire sequencing of the bacterial genome revealed numerous pseudogenes (inactive reading frames with functional counterparts in M. tuberculosis) which might be responsible for the very limited metabolic activity of M. leprae. The clinical demonstration of the disease is determined by the quality of host immune response. Th1-type immune response helps to kill the bacteria, but hosts are encroached upon when Th2-type response is predominant. The bacteria have affinity to the peripheral nerves and are likely to cause neuropathy. M. leprae/laminin-alpha2 complexes bind to alpha/beta dystroglycan complexes expressed on the Schwann cell surface. WHO recommends a chemotherapy protocol [multidrug therapy (MDT)] which effectively controls the disease and contributes to the global elimination program. Leprosy has been stigmatized throughout history, and recent topics regarding the disease in Japan are also discussed.

Localized lepromatous leprosy presenting as a painful nodule in a muscle

Lepromatous leprosy is a generalized disease usually presenting with numerous macules, papules, nodules or plaques involving wide areas of the skin. It is generally believed that in India lepromatous leprosy often originates from the borderline spectrum (Jha et al, 1991). Localized lepromatous or borderline lepromatous disease is a rare variant of multibacillary leprosy (Yoder et al, 1985; Jha et al, 1991; Pfaltzgraff & Ramu, 1994; Vijaikumar et al, 2001). This variant usually presents as a single nodule or a localized area of nodules and papules, while most of the body surface appears normal (Pfaltzgraff & Ramu, 1994; Vijaikumar et al, 2001). Its occurrence in our case as a single painful nodule in the bicep muscle of left forearm was indeed intriguing, such presentation being rarely reported in the literature.

Reactions in borderline leprosy

This is a retrospective study of 276 patients consisting of 157 active and 119 reactive patients of borderline leprosy. They were followed up for 10 years after sulphone monotherapy. The presenting symptoms were carefully examined from the records and systematically presented. Frequency of reactions was least in BT cases and most in BL cases. Risk factors of reaction appear to be the type of leprosy, multiplicity of lesions, high BI and, possibly, psychological stress. Biopsy of skin lesions was performed in all cases initially, and at the subsidence of the disease. Histological findings closely correlated with clinical classification. While all the cases showed clinical subsidence, histological subsidence was found in 200 (73%) cases, and the condition was static in 36 cases (13%). Immunological upgrading was seen in 110%, while 4% showed downgrading. Bacteriological status and lepromin reaction of active and reactive cases were compared. All these factors need to be taken into consideration for instituting prompt and proper treatment.

A fatal case of erythema necroticans

Erythema nodosum leprosum (ENL) classically presents as tender, erythematous nodules over the face, arms and legs. Severe ENL can become vesicular or bullous and break-down and is termed erythema necroticans (Jopling & McDougall, 1996) and is treated with corticosteroids. The causes of death in a majority of leprosy patients are the same as in the general population, with the exception of renal damage in lepromatous leprosy. There is possible increased mortality from side-effects of antileprosy drugs, steroids, or other drugs used in reactions, from toxaemia in severe reactions, and from asphyxia due to glottic oedema (Jopling & McDougall, 1996). We report here a case of erythema necroticans, the cause of death being septicaemia, secondary to skin ulcers and urinary tract infection, precipitated by corticosteroids.

Cytodiagnosis of erythema nodosum leprosum. A case report

BACKGROUND

The application of cytology in leprosy has been restricted to the evaluation of morphologic and bacterial indices by slit skin smears to facilitate diagnosis of cases according to the Ridley-Jopling scale. Isolated reports have now documented the use of fine needle aspiration cytology (FNAC) in the diagnosis of leprosy.

CASE

A 45-year-old male presented with the abrupt onset of multiple nodular eruptions all over the body. The clinical diagnosis was Sweet's syndrome. FNAC showed numerous neutrophils in a background of foamy macrophages. Special stains revealed the presence of a large number of fragmented acid-fast bacilli in the smears. A diagnosis of erythema nodosum leprosum (ENL) was made on FNAC.

CONCLUSION

The presence of neutrophils in a characteristic milieu of foamy macrophages is seen in lesions of ENL. Such a picture should prompt the cytologist to use a modified Ziehl-Neelsen stain to demonstrate acid-fast bacilli, as ENL can present as an acute episode in patients without a previous diagnosis of leprosy.

Feline leprosy: two different clinical syndromes

Feline leprosy refers to a condition in which cats develop granulomas of the subcutis and skin in association with intracellular acid-fast bacilli that do not grow on routine laboratory media. In this study, the definition was extended to include cases not cultured, but in which the polymerase chain reaction (PCR) identified amplicons characteristic of mycobacteria. Tissue specimens from 13 such cases from eastern Australia were obtained between 1988 and 2000. This cohort of cats could be divided into two groups on the basis of the patients' age, histology of lesions, clinical course and the sequence of 16S rRNA PCR amplicons. One group consisted of four young cats (less than 4 years) which initially developed localised nodular disease affecting the limbs. Lesions progressed rapidly and sometimes ulcerated. Sparse to moderate numbers of acid-fast bacilli were identified using cytology and/or histology, typically in areas of caseous necrosis and surrounded by pyogranulomatous inflammation. Organisms did not stain with haematoxylin and ranged from 2 to 6 microm (usually 2 to 4 microm). Mycobacterium lepraemurium was diagnosed in two cases based on the sequence of a 446 bp fragment encompassing the V2 and V3 hypervariable regions of the 16S rRNA gene a different sequence was obtained from one additional case, while no PCR product could be obtained from the remaining case. The clinical course was considered aggressive, with a tendency towards local spread, recurrence following surgery and development of widespread lesions over several weeks. The cats resided in suburban or rural environments. A second group consisted of nine old cats (greater than 9 years) with generalised skin involvement, multibacillary histology and a slowly progressive clinical course. Seven cats initially had localised disease which subsequently became widespread, while two cats allegedly had generalised disease from the outset. Disease progression was protracted (compared to the first group of cats), typically taking months to years, and skin nodules did not ulcerate. Microscopically, lesions consisted of sheets of epithelioid cells containing large to enormous numbers of acid-fast bacilli 2 to 8 microm (mostly 4 to 6 microm) which stained also with haematoxylin. A single unique sequence spanning a 557 bp fragment of the 16S rRNA gene was identified in six of seven cases in which it was attempted. Formalin-fixed paraffin-embedded material was utilised by one laboratory, while fresh tissue was used in another. The same unique sequence was identified despite the use of different primers and PCR methodologies in the two laboratories. A very slow, pure growth of a mycobacteria species was observed on Lowenstein-Jensen medium (supplemented with iron) and semi-solid agar in one of three cases in which culture was attempted at a reference laboratory. Affected cats were domicile in rural or semi-rural environments. These infections could generally be cured using two or three of rifampicin (10-15 mg/kg once a day), clofazimine (25 to 50 mg once a day or 50 mg every other day) and clarithromycin (62.5 mg per cat every 12 h). These findings suggest that feline leprosy comprises two different clinical syndromes, one tending to occur in young cats and caused typically by M lepraemurium and another in old cats caused by a single novel mycobacterial species.

Hepatic involvement in lepromatous leprosy

Hepatic involvement in a lepromatous leprosy (LL) patient is reported. The serum concentrations of aminotransferases were much higher than previously described in the leprosy literature. Other causes for hepatic damage were ruled out. Such hepatic involvement and elevation of aminotransferases have never been described in leprosy.

Histological changes in the nerve, skin and nasal mucosa of patients with primary neuritic leprosy

Primary neuritic leprosy (PNL) presents as a peripheral neuropathy with no visible skin patches and skin smears negative for acid fast bacilli. The pathogenesis of PNL is poorly understood. The aim of the study was to document the histological changes in the nerve, apparently normal skin and nasal mucosa in PNL and to study its significance to the pathogenesis of leprosy lesions. The study is based on a cohort of 208 PNL patients registered at the Schieffelin Leprosy Research and Training Centre, Karigiri. All patients had a nerve biopsy, 196 had a skin biopsy and 39 had a nasal mucosal biopsy. The findings reveal that PNL patients exhibit a spectrum of disease histologically in the nerve ranging from lepromatous to tuberculoid leprosy with a significant proportion (46%) manifesting a multibacillary leprosy histology. Findings in the apparently normal skin and nasal mucosa reveal that there are widespread changes due to leprosy in tissues such as the skin and nasal mucosa even when the disease appears clinically confined to a few nerves. PNL may be an early stage in the pathogenesis of the disease before the appearance of skin lesions. The number of nerves enlarged and lepromin status did not give any clue to the nature of underlying disease.

Leprosy. Recognition and treatment

Leprosy is a slowly progressive, chronic infectious disease caused by the bacillus Mycobacterium leprae. It is a very serious, multilating and stigmatizing disease in many parts of the world and early diagnosis and therapy is the most important strategy for its control. The skin and peripheral nerves are the most affected organs. It is highly infective, but has low pathogenicity and low virulence with a long incubation period. The geographical distribution of leprosy has varied greatly with time and it is now endemic only in tropical and subtropical regions such as India and Brazil. The diagnosis of leprosy is made from the clinical picture, but must be complimented by skin bacilloscopy and histopathology. Leprosy has a number of distinct clinical presentations. Indeterminate leprosy is frequently the initial form consisting of a few lesions that either evolves into the other forms or resolves spontaneously. Lepromatous leprosy is the more contagious form and affects mainly the skin. In addition, some peripheral nerves may be thickened and other symptoms maybe present. The tuberculid form affects the skin and nerves, although usually there are few lesions. There is also a form borderline between the lepromatous and tuberculoid forms. Current treatment of leprosy involves use of 3 drugs: rifampicin (rifampin); clofazimine; and dapsone. Multidrug therapy aims to effectively eliminate M. leprae in the shortest possible time to prevent resistance from occurring. The duration of therapy was recently reduced from 24 to 12 months. Other treatment options are under evaluation in both preclinical and clinical trials and a number show promise. The combination of rifampicin, ofloxacin and minocycline given as a single dose has been recommended for the treatment of paucibacillar leprosy. Only when physicians, other health workers, and the population in endemic countries become fully aware of, and able to recognize, the disease in its initial phase, will it be possible for therapy to be instituted at the very beginning with either the standard scheme or the newer ones. Intervention at such an early stage will avoid the onset of the more serious signs and symptoms, meaning that leprosy will eventually become a less important public health problem. Therefore, efforts must be made to alert populations at risk and all health workers of the importance of an early diagnosis and treatment in leprosy infection.