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Twenty-four tuberculoid (T)-type and 31 lepromatous (L)-type leprosy patients from Taiwan Provincial Lo-Sheng Leprosarium were enrolled in this study. Twenty-six age- and sex- matched normal subjects were also studied as a control group. The evaluation of their general and specific humoral immunity included B-cell subpopulations, 3 major classes of immunoglobulin (G, A and M) and antibodies in the IgG class against lepromin suspension and Bacillus Calmette-Guerin (BCG) sonicate. T-type patients showed a larger B-cell percentage than L-type patients (p less than 0.01). In general, patients with leprosy, both T and L types, had higher serum immunoglobulin levels than the control group. T-type patients showed greater antibody levels than the control group (p less than 0.05 for anti-lepromin and p less than 0.0001 for anti-BCG). L-type patients demonstrated a higher anti-BCG IgG level than the control group (p less than 0.0001). The level of anti-BCG IgG was more frequently above the cutoff level than that of anti-lepromin IgG in leprosy patients (p less than 0.01 for T, p less than 0.005 for L). In conclusion, humoral immunity is not impaired in leprosy patients. Discrepancies for T- and L-type patients among B-cell subpopulation, serum immunoglobulin levels and specific antibody levels reflect different aspects of cell-mediated immunity impairment. Though leprosy patients had elevated anti-BCG IgG levels, it is impossible to differentiate L- and T-type patients; specific antigens are needed for serodiagnosis of leprosy patients in Taiwan.

Lymphocyte transformation in response to PHA, M. leprae and BCG with the use of measurements of 3H-thymidine uptake, was studied in 10 normal controls, and 71 leprosy patients of different types histologically classified according to the Ridley-Jopling scale. Lepromin and PPD tests were done in each one of them. It was found that there was a generalized depression of immune responsiveness to PHA in all forms of leprosy. The immune responsiveness of lymphocytes to M. leprae continuously and gradually increases from the lepromatous (LL) towards the tuberculoid (TT) end of the spectrum. The loss of immune response of lymphocytes from lepromatous patients to M. leprae is specific as evidenced by their capacity to respond selectively to BCG when PPD-positive, irrespective of their place in the leprosy spectrum.

A study was made on the in situ characteristics of dermal infiltrates in the early and late lepromin reaction with monoclonal antibodies defining T cell subsets, Langerhan cells and Ia like antigens. The early reaction (24 hrs) was elicited either with standard Dharmendra lepromin or leprosin-A and the late reaction (3-4 weeks) was elicited with standard Dharmendra lepromin. In all, 15 biopsies were studied. Most lymphocytes in the infiltrates of both the lepromin and leprosin reactions were positive for OKT 11, Leu 3a, OKT 8 and Ia like antigens indicating thereby the presence of activated T cells. A high proportion of OKT6 + cells were also noticed in the infiltrates of these reactions. In the late reaction, the lymphocytes in the granulomas were predominantly activated T lymphocytes expressing OKT 11, Leu 3a, OKT 8 and Ia like antigens. Leu 3a + cells were scattered diffusely amidst the epithelioid cells. In contrast, OKT 8 + cells were present mainly in the peripheral region of the granuloma. A small proportion of OKT6 + cells were also seen in these granulomas. Ia like antigens and T6 antigens were not discernible on the epithelioid cells. No difference in the number of OKT6 + epidermal langerhan cells was observed in the various types of reactions.

HLA antigens in 157 unrelated Koreans with leprosy have been identified and compared with 162 healthy Korean controls. The patient group consisted of 124 with lepromatous leprosy and 33 with tuberculoid leprosy. Although no significant differences were detected between the two patient groups, several antigens were found to be increased in the combined patient group compared to healthy controls. Two Class I antigens were increased: HLA-A11 (22% vs 12%) and Aw33 (27% vs 14%). Four Class II antigens were increased: HLA-DR1 (16% vs 7%), DR2 (39% vs 21%), DRw9 (14% vs 6%) and DQw1 (74% vs 55%). HLA-DR4 (28% vs 48%), DRw53 (46% vs 69%) and DQw3 (50% vs 75%) in contrast were significantly decreased in patients. Interaction of DR1, DR2, DRw9 and DQw1 as risk factors was analyzed. HLA-DR2 appeared to be the strongest risk factor. No evidence for synergy between DR1, DR2 and DRw9 was detected. DQw1 was not significantly increased in patients in the absence of DR1 and DR2, and thus it was not apparent in this study that DQw1 was an independent risk factor.

The lymphocyte hyporesponsiveness to M. leprae of patients with active lepromatous leprosy has been well described. This immune defect is less well understood in terms of its time of origin, possible reversibility and specificity. To further examine the persistence and specificity of this abnormality, lymphocyte transformation tests of 93 leprosy patients to lepromin, BCG and PHA were studied. Among lepromatous patients, a decreased response to M. leprae was seen, whether the disease was active or inactive. Decreased responses to BCG were found in lepromatous patients with active disease, but not in those with inactive disease. The duration of patient symptoms was not associated with differences in LTT responses among the active lepromatous patients.

One hundred two armadillos captured from the wild were lepomin tested. Nine of them (8.8%) showed a positive Mitsuda reaction. The histopathological appearance of the reaction had a spectrum showing tuberculoid, borderline tuberculoid, borderline lepromatous, and lepromatous histology. It is possible that armadillos can develop all the different types of leprosy seen in humans. The armadillo is a good animal model to test protective vaccines against leprosy.

The author describes the progress made in our knowledge of tuberculoid leprosy since the original case of Jadassohn in 1898. The numerical importance of T patients in different parts of the world is reviewed and their role in the transmission of the disease discussed. An analysis is made of the subgroups into which T leprosy is divided according to the clinical symptoms, bacteriology, histopathology and immunology in the Madrid classification as well as in the Souza-Lima-Souza Campos and Ridley-Jopling studies. The author concludes that a majority of T patients are immunologically stable and belong to two well defined groups, the first called T annular in the Souza-Lima-Souza Campos study and TT in the Ridley-Jopling classification and the second called T reactional by S.L.-S.C. and BT by R.J. Taking into account the high proportion of T cases in most epidemiological situations, their generally accepted good prognosis under treatment and the present availability of several drugs of proved efficacy, the author suggests to carry out in T leprosy under controlled conditions a trial of a number of therapeutic regimens of not more than 12 months duration. Follow-up periods will make possible medium and long-term evaluation of results after 3 and 5 years respectively of the initiation of the chemotherapeutic regimens. The practical implications of effective and well tolerated short-term therapy in T leprosy is stressed. Its widespread use in field programmes will represent among other advantages a considerable economy in personnel and drugs costs. The use of a single protocol is recommended. The one worked out by THELEP for therapeutic trials in lepromatous leprosy could be adopted with a few changes made necessary because of the morphological and bacteriological differences between L and T leprosy. It is suggested that, if the results of the trial are successful, similar regimens could be tried in indeterminate leprosy.

Three lepromin-positive armadillos and three lepromin-negative armadillos were tested intradermally with 100 micrograms of phenolic glycolipid-I (PGL-I) in 0.1 ml of normal saline. Positive delayed-hypersensitivity granulomas at 21 days in the lepromin-positive animals and negative responses in the lepromin-negative animals were obtained. These observations suggest that purified PGL-I is capable of eliciting cell-mediated immune or delayed-hypersensitivity responses in animals sensitized to Mycobacterium leprae.

Clinico-bacteriological profile of 106 leprosy patients below 15 years of age was studied. Majority of the patients were males and fell in the 10-15 years age group (p less than 0.01). Nearly 89% had not received any prior treatment because of financial constraints. Seventy per cent gave a positive history of contact with adult patients who were mainly of the lepromatous variety (p less than 0.01). Skin lesions were present in 103 cases, mainly on the exposed areas and their number was found to increase significantly with advancing age (p less than 0.01). These lesions were hypopigmented patches in 71% of the children and erythematous in the rest. Cutaneous sensations were affected in most of the patients while nerve thickening was observed in 45. Positivity of the skin smears increased significantly as the number of skin lesions per patient increased (p less than 0.05). With advancing age, the disease moved from the tuberculoid end of the spectrum towards the lepromatous end (p less than 0.01).

Twenty-eight armadillos were lepromin tested and infected with M. leprae; 18 intravenously and 10 intradermally. The lepromin test was repeated after 3 months and at intervals of 6 months thereafter until their death or sacrifice up to 30 months. The one animal with tuberculoid lepromin was resistant and 14 of the 16 with lepromatous lepromin developed generalized disease. Of the 11 with borderline lepromin, 6 developed disseminated disease and 5 were resistant. There is a definite relationship between resistance and tuberculoid lepromin in the armadillo. Repeated lepromin testing had no effect in the rate of infection and the course of the disease in animals infected intravenously. In the intradermally infected animals the results were inconclusive. Whereas all the 20 animals with disseminated disease showed lesions in the liver, spleen and lymph nodes, only 4 animals had sciatic nerve involvement. Peripheral nerve trunk is not necessarily the preferred site in the armadillo. Lung lesions were an important cause of death in lepromatous armadillos.

From the field of view of own observative and experiences was tried to outline the present situation in leprosy. It is referred to the results of the modern epidemiological, bacteriological, immunological and medicamentous leprosy research which was particularly stimulated under the impression of the increasing DDS-resistance of the leprosy bacteria. At present ambulatory polychemotherapy, sometimes combined with a vaccination technique, is in the centre of the world-wide combat programme against leprosy. In no other infectious disease, however, social-economical points of view are so important as in leprosy and in the opinion of the author they are finally also decisive for an actually successful and permanent combat.

Early and total E--rosettes counts were made in the leprosy patients of different clinical types classified histologically and compared with those of healthy controls. The T-cell population in LL cases were found to be significantly lower than in other types of leprosy cases and controls. The study of the E--rosette formation at different times of incubation indicated that any point of observation could be used for comparison. However, early (1 hour--2 hour) counts help to distinguish the LL cases from other types of leprosy. A good correlation was noticed between the percentage of rosettes and lepromin test.

In an attempt to further define their immunopathogenesis, the cellular infiltrates of Mitsuda reactions were studied in situ using immunoperoxidase techniques and monoclonal antibodies. Lepromin A-elicited Mitsuda reactions from six patients with borderline tuberculoid leprosy (TT/BT or BT) and three healthy kindred and contacts of lepromatous patients were examined. In the dermis, cells bearing the Leu4 phenotype comprised a mean of 61% of the infiltrate; the Leu3a, 47%; the Leu2a, 17%; anti-IL-2, 0.2%; anti-Tac, 1.5%; and cells bearing the Ia phenotype were virtually universal; OKT6 positive cells were present. The Leu2 phenotype was sequestered to the periphery of epithelioid tubercules. In the epidermis, there were mild, focal lymphocytic infiltrates, hyperplasia of epidermal Langerhans' cells, and well-developed expression of Ia upon nucleated keratinocytes. These findings, when compared with those of a better-defined reaction, tuberculin, are further evidence that the Mitsuda response may be a delayed-type hypersensitivity phenomenon.

An unusual principle has been observed: when obliged to reproduce in a new medium ill-adapted to their development, mycobacteria abandon their common mode of reproduction--transversal division--and adopt a mode of evolution that puts less of a strain on their vitality: the long evolutive cycle, first described in 1899. In an initial step, the mycobacilli used for seeding purposes undergo auto-bacteriolysis, creating a cyanophilous fundamental substance which is in fact a symplasm due to the ex-bacillary microgranules, a multitude of independent and mobile genes. These genes merge according to a new and simpler arrangement: thus are formed the slender cocci that take the place of the amorphous cyanophilous substance. These cocci, released in the culture, multiply and lengthen into bacilli which merge to form a new amorphous cyanophilous substance. This new amorphous cyanophilous substance, thanks to another rearrangement of its genes, then forms a "crust" which undergoes exfoliation and crumbles into alcohol-acid-fast (a.a.f.) bacilli. Coryneforms and a.a.f. bacilli (mycobacteria) constitute two distinct agents with different and even occasionally opposite pathogenicities, as can be observed in co-cultures of Coryneforms (Hansen's bacillus or bacillus Calmette-Guérin) and tubercle (Koch's) bacillus. In such co-cultures, the tubercle bacilli progressively lose their vitality and virulence while, inversely, the Coryneforms reinforce their pathogenicity. Co-cultures of BCG and lepromin thus constitute an association with a particular property and most likely an auto-vaccinating activity against leprosy which is the subject of on-going research.

Skin tests were conducted on 3 lepromatous, 3 dimorphous and 6 tuberculoid leprosy patients and 3 others not suffering from leprosy with lepromin, purified protein derivative from M. leprae of armadillo origin and tuberculin. Results show that a delayed hypersensitivity reaction could be produced with PPD in 72 hours on all Mitsuda positive cases, with one anomalous exception, without cross reaction to tuberculin. The results were promising from the point of view of substituting lepromin with PPD in usual tests.

The presence or absence of suppressor cells in leprosy patients was investigated by measuring peripheral blood lepromin-induced suppression of the Con A response. Significant suppressor activity was measured in 15 of 15 untreated or recently treated patients with lepromatous leprosy and 3 of 5 patients with borderline lepromatous leprosy. In addition, in patients with lepromatous leprosy, suppressor cell activity was found in 10 of 14 patients that had been under treatment for more than 1 year but in only 2 of 27 patients who had active or thalidomide controlled erythema nodosum leprosum. Suppression was observed in only 5 of 29 tuberculoid leprosy patients, 1 of 6 patient contacts, and 0 of 11 normal controls. The differences between the lepromatous or borderline lepromatous group as compared with the tuberculoid group were statistically significant (P less than 0.001). Our findings confirm the presence of lepromin-triggered suppressor cells in the peripheral blood of patients with lepromatous leprosy. These suppressor cells may contribute to the selective unresponsiveness of lepromatous patients to the antigens of Mycobacterium leprae.

The lepromin test was studied in 64 medical students and in a control group consisted of 40 patients from the orthopedic clinic. Both groups matched with respect to age and sex, but differed with regard to socio-economical conditions. The Fernandez reaction showed low frequency of positive results in both groups: 10% in the first group and 5,6% in the second one. This difference was not significant. The Mitsuda reaction showed high frequency of positive results: 98,4% in the medical students and 85,0% in the control group. This difference was significant. The authors discuss the factors that might have caused the high positivity of the lepromin test among the medical students.

The M. leprae-culture isolate, being a culture, is identified by biochemical criteria. Majority belong to either M. avium-intracellulare-scrofulacieum complex, or corynobacterium group. The identification is also determined by serological methods using soluble sonicates. Skin tests with heat-killed suspension often give positive Mitsuda response and hence the isolates are discarded as non-M. leprae. The data on ICRC strains show that Dharmendra type antigen prepared from ICRC bacilli compares very well with lepromin in lepromatous patients. The CMI/DTH tests in mice by FPE and LMI technique have experimentally demonstrated that ICRC bacillus is the first cultivable mycobacterium that can sensitize mice against lepromin. These data also brought out antigenic differences between the ICRC strains. The clinical trial on ICRC vaccine has shown that the ICRC bacilli is immunogenic in Man. The biochemical data on ICRC strain show that they possess DOPA-Oxidase and can express biochemical character of 9/10 similarity index with M. leprae with appropriate substrates in the medium. Thus, the ICRC strains possess both M. leprae and M. avium characters. An hypothesis is proposed to explain these observations--The 'Janus face' of M. leprae--by proposing a relationship between M. leprae and its culture isolates, e.g. ICRC bacilli (1). The M. leprae-culture isolate may by a recombinent of M. leprae with M. avium background (2). The ML-isolate may express the CMI related antigenic determinants corresponding to that of M. leprae in the biopsy (3). The CMI related antigens of whole bacilli in the ML-culture isolate may be inducing type as against only eliciting antigen expressed by M. leprae (4). Recombination may provide immunogenicity as well as 'in vitro' growth potential to the ML-culture isolate (5). Absence or failure to express inducing antigen by M. leprae maybe alternate biological escape mechanism from immune surveillance for survival in vivo, with or without suppressor mechanisms.

Macrophage culture was performed on 45 healthy adults who were initially categorised on the basis of their Lepromin reactivity using Dharmendra antigen. There were 25 individuals in the Lepromin positive group and 20 in the Lepromin negative group. The cultures were challenged with M. leprae and the macrophages studied at varying time intervals of culture. No difference was evident in the behaviour of cultured macrophages to M. leprae in both the groups. The Lepra bacilli were phagocytosed by the macrophages and retained essentially intact till the termination of culture. The Lepromin reactivity of a healthy individual was not reflected on the macrophage function in vitro. The observations suggested against the possibility of an intrinsic genetically determined macrophage defect in dealing with M. leprae.

The type of leprosy which develops after infection with Mycobacterium leprae is influenced by the presence or absence of HLA-DR3, as has been demonstrated in an ethnic group originating from Surinam. In the present study we investigated in this same ethnic group the role of HLA-DR, and of HLA-DR3 in particular, in monocyte-T cell interactions during leprosy specific proliferative responses in vitro. HLA-DR3 heterozygous T cells from tuberculoid leprosy patients were cultured with antigen and either HLA-DR3 positive or HLA-DR3 negative homozygous HLA-DR compatible allogeneic monocytes as antigen presenting cells (APCs). T cell proliferative responses with DR3 homozygous monocytes as APCs, were observed to be decreased as compared to T cell proliferative responses with DR3 negative homozygous monocytes as APCs. Furthermore, although the leprosy specific monocyte-T cell interactions were shown to be restricted for HLA-DR, in the anti-MLW-1 response HLA-DR3 appeared to function as a restricting element poorly or not at all. These observations may imply, that an in vitro correlate has been found for an (HLA associated) genetic control of leprosy in vivo.

Three multidrug regimens all containing rifampin and dapsone have been tried for the treatment of 278 cases of paucibacillary leprosy. Regimen I was the one recommended by the WHO Study Group. Regimen II was the same as Regimen I with depsone alone continued for a further 6 months. Regimen III was the same as Regimen II but rifampin was given daily for the first 7 days. The patients were comparable with regard to disease classification, lepromin status, bacteriological status, and number of lesions. As reported earlier, the disease inactivity rates by 1 year of treatment were much greater with Regimens II and III than with Regimen I (94% and 97% vs 76%). Early reaction was seen in 6% of those in Regimen III and in none in Regimens I and II. Late reaction was observed in 9% of those in Regimen I and none in Regimens II and III. During 3 1/2 years of follow up, 13% of the cases in Regimen I, 1% in Regimen II, and 2% in Regimen III relapsed. Since the patients in the three regimens were otherwise comparable, it is concluded that the high inactivity rate, low relapse rate (1%-2%), and no early or late reaction as observed in Regimen II patients were because of adequate treatment.

The authors carried out 3 double blind trials to determine the correlation between the early and the late lepromin reactions and to verify the practical and control values of the 48 hours or Fernandez reaction. Children and adolescents non-contacts were tested with human lepromin (40 x 10(6) bacilli/ml) and different concentrations of armadillo lepromin (160, 40, 20, 10, 5, 2,5, and 1 x 10(6) bacilli/ml). The conclusions are as follows: 1. The coefficients of correlation (r values) point out that the correlation between the two reactions is poor or almost null. 2. The negative or doubtful reactions, the most often observed, have no practical value because they are almost always followed by a positive Mitsuda reaction. 3. The positive Fernandez reaction was always followed by a positive Mitsuda reaction. Thus it has practical importance. However as the frequency of early positivity is low with human and armadillo lepromin of lower concentrations, recommended in routine testing, the 48 hours reading is unnecessary and without control value. It would represent a loss of time and money.

The early lepromin reaction was studied clinically and histologically in 38 leprosy patients. There was a quantitative and a qualitative difference in the character of the early inflammatory response to lepromin in the different groups of leprosy patients. In tuberculoid patients, the extent and degree of inflammation and the density of lymphocytic infiltration were maximal. In the polar lepromatous group, the inflammatory reaction was far less intense, and lymphocytes were scarce or absent. An intermediate histology was noted in the borderline and indeterminate groups of patients. In 11 patients with negative clinical reactions, the histology showed moderately dense lymphocytic infiltrations. The paucity of the clinical reaction could be due to the injection and localization of the antigen in the mid- and deep dermis. The correlation between early and late lepromin reactivity, both clinically and histologically, in the polar tuberculoid group and the polar lepromatous group was good. In the borderline and indeterminate groups, only the correlation between the early and late histological reactions to lepromin was good. The relationships between the early and late clinical reactions to lepromin showed marked variation. It is suggested that the early reaction is as good an indicator of lepromin reactivity as the late reaction in all forms of leprosy but only if it is assessed histologically.

ICRC bacilli, the cultivable leprosy-derived mycobacteria, isolated from lepromatous nodules of leprosy patients were found to be immunogenic in BALB/c mice at a dose of 2 X 10(7) acid-fast bacilli when injected by the intradermal (i.d.) route. The sensitization to lepromin and ICRC antigens was measured by the foot pad enlargement (FPE) method. The same dose of bacilli when injected by intravenous (i.v.), intraperitoneal, and subcutaneous routes induced immune tolerance in mice as indicated by reduction in the FPE to the test antigens. The spleen cells obtained after i.v. injection of ICRC bacilli/Mycobacterium leprae after adoptive transfer brought about suppression of delayed-type hypersensitivity in sensitized as well as nonsensitized recipients, indicating production of suppressor cells after i.v. injection. Similarly, the tolerance induced by i.v. injection of M. leprae in mice could be partially converted to immunity by i.d. sensitization with live BCG and two strains of ICRC bacilli (C-44 and C-75).

To test the capacity of cimetidine to enhance cellular immunity in patients with lepromatous leprosy (LL), cimetidine was given for one month to 29 inactive LL patients and 3 active LL patients. Immune function was monitored with skin tests (lepromin, PPD, candida, and trichopytin), lymphocyte transformation tests (phytohemagglutinin, BCG, and Dharmendra lepromin), and quantitation of peripheral blood lymphocyte subpopulations. A small but significant "booster" response to PPD was the only change observed in the study of patients with inactive disease, and leprosy-related reactions did not occur. In the few active LL patients studied, neither immune enhancement nor leprosy-related reactions were observed. The results of this investigation suggest that cimetidine can be used safely in patients with inactive lepromatous leprosy.

Although the mechanism of immunologic unresponsiveness in lepromatous leprosy remains unknown, it has been shown that interleukin-2 (IL-2) production is defective in these patients. Peripheral blood mononuclear cells (PBMC) were isolated from treated (less than 16 months) and untreated leprosy patients as well as household contacts; age, sex, ethnically matched control subjects; and laboratory staff. PBMC were cultured for 6 days with sonicated Mycobacterium leprae (1-10 micrograms/ml), Dharmendra lepromin (1:10), or phenolic glycolipid-I (PGL-I) (0.05-5.0 micrograms/ml) in medium supplemented with various concentrations of recombinant IL-2 (rIL-2) or cultured for 3 days with one of the three mycobacterial antigens in the presence of concanavalin A (ConA). TT/BT patients and household control subjects had a robust response to M. leprae and lepromin, but were unresponsive to PGL-I delivered in liposomes. PBMC from LL patients did not respond to any of the three antigen preparations. rIL-2 induced proliferation of PBMC both in leprosy patients and control subjects regardless of the presence or absence of the three leprosy antigen preparations. This antigen nonspecific augmentation of proliferation by the wide range of doses of rIL-2 employed makes difficult the interpretation of the enhanced thymidine incorporation noted when rIL-2 is added in the presence of antigen to cultures of lymphocytes from LL patients. Our studies are at variance with reports that leprosy antigens, specifically PGL-I, induce immunological suppression, in that mycobacterial antigens did not cause significant suppression of the ConA-induced proliferations of PBMC from patients.