Silent iritis in treated bacillary negative leprosy

Iridectomy specimens from 59 leprosy patients who had adequate medical records of whom 33 belong to the lepromatous (LL) leprosy variety and 16 normal controls were studied histopathologically. All patients were bacteriologically negative and had received dapsone followed by multidrug therapy (MDT), or MDT only, or only dapsone for varying periods. It was found that leprosy, particularly lepromatous disease, did not significantly decrease the age of formation of cataract. Of the 33 LL patients studied 60.6% had silent iritis. The duration of treatment had no obvious influence on the persistence of iritis. Treatment with only 2 years of MDT for LL patients did not significantly increase the prevalence of persistent silent iritis compared to those who received other types of antileprosy therapy for long periods. It is pointed out that chronic iritis is a serious complication that continues even after the patient is declared clinically and bacteriologically cured, especially in patients who had a history of chronic iritis clinically.

Viability of Mycobacterium leprae in skin and peripheral nerves and persistence of nerve destruction in multibacillary patients after 2 years of multidrug therapy

The pathological changes, bacterial load, and viability of Mycobacterium leprae in the skin and nerves of nine lepromatous leprosy patients who had undergone 2 years of multidrug therapy (MDT) were studied. M. leprae and varying amounts of their remnants were present in the nerves and skin of all but one patient. M. leprae isolated from skin biopsies of six patients and nerve biopsies of nine patients were inoculated into mouse foot pads. No growth was obtained from any one of them. During the electron-microscopic examination of three nerve biopsies, only one specimen showed a small number of solid-staining M. leprae. These findings would explain the low relapse rate in patients treated with 2 years of fix-duration MDT. Results of a long-term follow up of patients is awaited with interest. The possibility of nerve paralysis due to intraneural microreaction and fibrosis consequent to the continued presence of dead bacterial remnants should be seriously considered.

Nerve in reversal reaction

1. Much of the nerve destruction in leprosy takes place during the reactive phase, both during ENL reaction and RR. 2. The high risk patients expected to develop RR are borderline patients with generalized lesions (more than 10 skin lesions) and those presenting with three or more thickened nerve trunks. 3. In RR there is a sudden enhancement of already existing DTH to M. leprae and its antigens resulting in the release of excessive quantities of TNF alpha, INF gamma, and IL-2. The triggering mechanisms of this phenomenon is poorly understood. 4. The already existing granulomas suddenly increase considerably in size due to oedema and rapid influx of lymphocytes, Langhan's and foreign body giant cells. Fragments of M. leprae are also present in the granuloma of some patients. 5. In RR, the acute granulomatous inflammation can produce destruction of nerves even to the extent of causing caseous necrosis of the nerve tissue and irreversible paralysis. The swelling of the nerves due to sudden increase in inflammatory cells and oedema within an unyielding perineurium produce ischaemia and transient paralysis. 6. With prompt administration of anti-inflammatory drugs, paralysis recovers quickly, if it is of ischaemic origin; but will not recover if the Schwann cells and other nerve tissues are destroyed as a result of the immune granuloma. 7. A course of corticosteroids for six months along with anti-leprosy therapy is suggested in high risk patients as a preventive measure. 8. Further the serious problem of continuing nerve damage after clinical cure should be urgently tackled.

Viability of Mycobacterium leprae in lepromatous patients after five years of dapsone monotherapy supplemented with two years of multidrug therapy

Eleven lepromatous leprosy (LL) patients with a bacterial index (BI) of three and above who had undergone two years of multidrug therapy (MDT) and yet had positive skin smears at the end of treatment were chosen for this study. Biopsies from the skin and lymphnodes were histopathologically evaluated for the presence of granulomas and M. leprae. M. leprae isolated from the skin and lymphnodes were inoculated into the foot-pads of normal mice to test their viability. On histopathological examination of the biopsy specimens, it was found that granulomas and M. leprae were present in the skin and lymphnode biopsies of all patients except two, in whom, although granulomas persisted, M. leprae were not found in skin biopsy specimens. No growth was obtained in the foot-pads of mice inoculated with organisms isolated from skin and lymphnode biopsies of all 11 patients indicating a near complete bacterial kill. That would account for the extremely low relapse rates reported until now in LL patients who had undergne two years of MDT.

Transmission of leprosy in nude mice through thorn pricks

The dorsum of the feet of 10 nude mice was smeared with 10(7) Mycobacterium leprae and then pricked with cactus thorns contaminated with M. leprae. In 15 months five of them developed lepromatous nodules at the infected site and disseminated lesions in the ears, nose, tail and the organs of the reticuloendothelial system. Penetrating injuries through unprotected skin contaminated with M. leprae from the environment may play a role in the transmission of leprosy in humans.

Armadillos (Dasypus novemcinctus) as a model to test antileprosy vaccines; a preliminary report

The efficacy of two candidate leprosy vaccines, BCG and a mixture of BCG and killed Mycobacterium leprae, was tested in 62 armadillos caught in the wild. The abilities of the vaccines to convert lepromin-negative armadillos to a positive reaction were compared with a group of control animals. Both vaccines upgraded subsequent lepromin skin-test histopathology. The conversion results parallel the protection values obtained in some BCG vaccine trials against leprosy in humans. Before conducting expensive human trials with new antileprosy vaccines, it would be worthwhile first to evaluate them in the armadillo model.

Extent, origin, and implications of observer variation in the histopathological diagnosis of suspected leprosy

Identical slides from 100 biopsies obtained from individuals suspected of having leprosy, ascertained in a total population survey in Malawi, were examined twice, independently, by three histopathologists. Results were reported in a standard protocol, and were compared among themselves and with a standardized clinical assessment of each "suspect." The proportion of biopsies considered to show definite evidence of leprosy ranged from 29 to 55 among the six evaluations (twice by each of three histopathologists). Comparisons of variations within and between histopathologists revealed three different patterns. Two of the pathologists were very consistent as individuals, but differed markedly between themselves in that one was the least inclined and the other the most inclined to report definite evidence of leprosy. The third pathologist was less consistent, reporting appreciably more definite leprosy on the first than on the second examination of the same biopsies. Although acid-fast bacilli (AFB) were reported on at least 1 examination in 40 of the biopsies, they were observed in all six examinations of only six of the biopsies. There was greater agreement regarding classification than regarding diagnosis, except with reference to the indeterminate category which was employed more frequently by one histopathologist than by the other two. A workshop of participants at the end of the investigation highlighted several reasons for the variations observed. The fact that AFB were reported in only nine biopsies by one histopathologist but in 33 by another reveals the importance of the examination method and time in arriving at a diagnosis of leprosy. The differences in the interpretation of cellular evidence of inflammation revealed the need for further studies of nerve-related pathology in nonleprosy conditions to serve as a reference against which to judge possible evidence of leprosy per se.

Lepromin skin testing in the classification of Hansen's disease in the United States

Hansen's disease, or leprosy, although a relatively uncommon disease in the United States, continues to be important because of its implications--physical, psychological, and social--for the patient. Prognosis and treatment of the disease are based largely on clinical classification, which ranges from the multibacillary "lepromatous" to the paucibacillary "tuberculoid" forms, depending on the patient's specific immune capabilities. Traditionally, skin testing with lepromins--suspensions of the etiologic agent of Hansen's disease, Mycobacterium leprae--have been used as adjuncts to clinical parameters for classification in endemic areas. However, these have not been systematically studied in the United States. This report describes the results obtained from skin testing 38 volunteers (22 patients and 16 uninfected persons) with standard lepromin preparations. These results support the adjunctive value of lepromins for clinically classifying Hansen's disease in our "hypoendemic" population.

Detection of Mycobacterium leprae and the potential for monitoring antileprosy drug therapy directly from skin biopsies by PCR

An improved protocol for PCR analysis of Mycobacterium leprae-infected tissues, based on enzymatic lysis, has been developed and used to demonstrate the feasibility of using PCR for detecting M. leprae in routine skin biopsies taken from leprosy patients throughout the clinical spectrum. Of 92 multibacillary patients tested, 99% were PCR-positive using gel electrophoresis or DNA hybridization to detect the amplified product. Similar analysis of paucibacillary patients, in which only one of 27 biopsies had demonstrable AFB microscopically, gave a positivity rate of 74%. No PCR signals were demonstrated from skin biopsies from seven patients with non-leprosy dermatoses and one AIDS patient with a disseminated atypical mycobacteriosis. Evaluation of leprosy patients with antileprosy drug therapy prior to biopsy demonstrated that PCR signals were either greatly diminished or absent after 2 months of continuous antibiotic therapy. PCR was also able to detect the presence of M. leprae in tissues of patients receiving antibacterial therapy when patients were suspected of harbouring drug-resistant M. leprae.

The pathogenesis of leprosy in the nine-banded armadillo and the significance of IgM antibodies to PGL-1

Twenty-seven nine-banded armadillos captured from the wild and tested free of wild M. leprae infection were distributed into four groups. They were injected at the right hind footpad with saline suspensions of M. Leprae at doses of 10(3), 10(4), 10(5) and 10(6). PGL-1 antibody levels were estimated using an ELISA test, twice during six months before the infection and every two months after the infection. One animal from each group was sacrificed at 6, 12, 18, 24, and 30-month intervals and another eight at unspecified intervals. A thorough autopsy and histopathological examination were conducted on all of them. Of the 27 animals, 18 developed the infection. In 10, there were granulomas at the site of inoculation and in 17 the regional lymph nodes were infected. The disease spread extensively to other lymph nodes and to the liver and spleen and then to the other organs. Peripheral nerves were invaded by M. leprae in only five animals. PGL-1 antibody levels registered a positive reading in only six of the 18 animals with the infection. In armadillo leprosy, the lesions did not persist at the site of entry in all animals M. leprae multiplied in the macrophages at the site of inoculation and the reticuloendothelial cells of the lymph nodes before they spread to other organs. There was evidence of invasion of endothelial cells of capillaries and possible bacteraemia even at an early phase of the infection. Peripheral nerves were not the preferred sites of entry or multiplication of M. leprae. Progressive increase in PGL-1 antibodies was recorded in five lepromatous armadillos with disseminated infection and high bacterial load. However, PGL-1 antibodies response was not sensitive enough to detect early disease.

Comparison of polymerase chain reaction technique with other methods for detection of Mycobacterium leprae in tissues of wild nine-banded armadillos

Thirty, nine-banded armadillos weighing between 3 and 5 kilograms trapped from an area endemic for armadillo leprosy were collected at random; killed, autopsied and examined histopathologically. Also, one of the right inguinal lymph nodes was removed under sterile precautions and examined using PCR, direct smear examination, mouse footpad study, culture in laboratory media and histopathology with a view to detecting Mycobacterium leprae. Blood was collected at death and tested for IgM antibodies to PGL-1. According to the PCR study of the inguinal lymph nodes 16 of 30 armadillos (53.3%) had evidence of M. leprae. Significant levels of IgM antibodies to PGL-1 and identifiable lepromatous granuloma in inguinal lymph nodes were found in 2 animals (6.7%) with advanced disseminated disease. The prevalence of generalized leprosy according to autopsy study was 13.3% and according to histopathological examination of ear tissue 3.3%. The presence of M. leprae in the tissues evoked no special tissue reaction in the early stages. The pattern of spread of the disease in 2 animals closely resembled that found in experimental animals infected intracutaneously. Initiation of infection by inoculation of M. leprae through thorn pricks remains a distinct possibility.

Nine-banded armadillo (Dasypus novemcinctus) as an animal model for leprosy

Dr. Dharmendra was one of the most distinguished leprologists of our time. He loved India so much that he offered his entire life to fight leprosy, a major health problem in India. He realized the great need in this much neglected field of medicine and willingly gave his utmost, whatever be the cost. He served in the field of leprosy with great distinction and he earned the respect of his fellow workers from all over the world. He made outstanding contributions to the study of leprosy, the identification and isolation of the active principle in the lepromin reagent, the use of lepromin test for identifying persons susceptible to leprosy, the use of an antileprosy drug as a means of chemoprophylaxis, the nurturing of the Indian Journal of Leprosy and developing it as one of the foremost leprosy journals, are a few of his major contributions. He received many well deserved national and international honours and awards. I first met Dr. Dharmendra in 1956 and feel privileged to have known him and to be associated with him all these years. I am honored to be asked to contribute this paper for a publication meant to pay tribute to his memory.

Seasonal and spatial trends in the detectability of leprosy in wild armadillos

A survey for leprosy among 565 armadillos from Louisiana and Texas found IgM antibodies to the phenolic glycolipid-1 antigen of Mycobacterium leprae in 16% of the animals. There were no geographic trends in the distribution of prevalence rates between the sites and the disease probably has a much greater range. Repeat observations in one location showed significant seasonal variations in the observable antibody prevalence rate, but the yearly average remained similar. Infected armadillos tended to be heavier, and the females usually had plasma progesterone concentrations indicative of sexual maturity. Using these characteristics to stratify the populations into adult and sub-adult cohorts, variations in the observable leprosy prevalence rate were seen to be proportional to changes in the age structure of the populations. Leprosy appears to be maintained in steady state within some regions, and nearly a third of the adult armadillos in Louisiana and Texas harbour M. leprae.

The systemic influence of recombinant interleukin 2 on the manifestations of lepromatous leprosy

14 patients with lepromatous leprosy received twice daily injections of 10 micrograms recombinant interleukin 2 (rIL-2), by the intradermal route, in the skin of the back for 8 d (total dose, 160 micrograms). Lymphokine administration was accomplished without drug toxicity, or the development of acute nerve damage. The majority of patients developed nontender axillary lymphadenopathy during the course of treatment. Local injection sites showed progressively larger zones of induration, peaking at 24 h and persisting for many days. Early 12-h reactions were of a macular, erythematous nature and exhibited an increasingly striking diurnal variation. The morning injection sites were three- to fourfold larger in diameter than those placed in the evening (9 am to 9 pm). Systemic manifestations of intradermal rIL-2 administration were noted. Peripheral blood T cells, including CD4+ and CD8+ phenotypes, increased 2-2.5-fold and NK cells increased sixfold. Elevations in [3H]TdR incorporation into peripheral blood mononuclear cells occurred to a variety of mycobacterial antigens, but not to those of Mycobacterium leprae. Within 2 wk, biopsies at sites far removed from the back showed increased infiltration of mononuclear cells in 12 of 14 patients. Immunocytochemistry revealed the presence of newly emigrated CD4+ T cells, monocytes, and dermal CD1+ Langerhans cells. Endothelial cells of small dermal vessels expressed major histocompatibility complex class II determinants on their surface. Transmission electron microscopy of these specimens revealed markedly enlarged endothelial cells with many surface projections extending into the lumen as well as extravasating lymphoid cells. The numbers of acid-fast M. leprae in the peripheral sites were examined by slit smear and in biopsies of matched leprosy lesions taken before and after IL-2 administration. Within 2 mo, slit smears showed a 0.5 log or greater reduction in 12 of 14 patients, with a mean for all patients tested of 0.5 log units. Biopsy specimens showed a 1 log unit or greater reduction in the bacterial index (B.I.) in 6 of 14 patients. Historical controls in this Nepalese population showed a 0.5 log unit reduction after multidrug therapy over a period of 12 mo. Thus, after 8 d of IL-2 injections, a fivefold reduction in B.I. was observed during the first 2 mo of the study. Antibody levels against M. leprae phenolic glycolipid 1 (PGL-1) and lipoarabinomanan B were markedly elevated after IL-2 injections, while PGL-1 antigen levels were reduced. We conclude that the administration of rIL-2 has had a significant effect in decreasing the total body burden of M. leprae.(ABSTRACT TRUNCATED AT 400 WORDS)

An attempt to produce experimental tuberculoid leprosy in the nine-banded armadillo

In an attempt to produce experimental tuberculoid leprosy, three nine-banded armadillos, two with borderline tuberculoid lepromin reaction, and one with tuberculoid lepromin reaction, were chosen. They were injected subcutaneously in a four square centimetre area in the abdominal skin with saline suspension of 6.5 x 10(7) M. leprae. Induration of skin at the injected site appeared in 24 hours and persisted for 6 months in one and for 18 months in the other two animals. Histopathological examination of the infected site at 6 weeks, 18 and 20 months showed progressively decreasing granulomatous inflammation; but the cutaneous nerves were uninvolved. Autopsy examination of the three animals failed to show disseminated disease. Since there was no evidence of nerve involvement, experimental transmission of tuberculoid leprosy to armadillos could not be established in this study.

Intralesional variations from lepromatous to tuberculoid histology--a case report

A patient showing simultaneously in one lesion clearly demarcated histopathological changes consistent with borderline lepromatous and tuberculoid leprosy is described. To our knowledge, this is the first recorded case of such an unusual histopathological appearance.

Widespread intradermal accumulation of mononuclear leukocytes in lepromatous leprosy patients treated systemically with recombinant interferon gamma

Intradermal administration of recombinant interferon gamma (rIFN-gamma) to lepromatous leprosy patients has converted the local histology toward a tuberculoid pattern. However, such changes have been confined to the site of injection. In contrast, in the present study, marked, intradermal accumulation of CD3+, CD4+, CD8+, and CD1a+ T cells and Leu-M5+ mononuclear phagocytes was induced at a distance from the sites of administration, in a dose-dependent manner, by 10 daily intramuscular injections of 10-30 micrograms rIFN-gamma/m2. Mononuclear cell infiltration began within 3 d of onset of rIFN-gamma therapy and persisted at least 8 wk. Intramuscular administration of rIFN-gamma to lepromatous patients receiving concurrent chemotherapy can safely induce widespread histologic features of an upgrading reaction.

Skin pigmentation from clofazimine therapy in leprosy patients: a reappraisal

Skin biopsy specimens from two lepromatous leprosy patients with dark brown pigmentation who were receiving long-term clofazimine therapy were studied. Ceroid-lipofuscin pigment was demonstrated inside macrophages that contained numerous phagolysosomes. These contained lipids and clofazimine that appeared as electron-lucent vacuoles and a lipofuscin pigment that was electron dense, granular, and lamellated. Although the presence of the drug in tissues contributed to the skin pigmentation, the main cause was a drug-induced, reversible ceroid lipofuscinosis.