Leonine facies: A unique presentation of T-prolymphocytic leukemia.

We report a 52-year-old man who presented with erythroderma and nodular lesions on face manifesting as "Leonine facies". He had impaired sensation over the face and was initially diagnosed to have lepromatous leprosy and was treated with antileprosy drugs. Investigations showed a total Leukocyte count of 550 X 109/l with 90% atypical lymphoid cells with prominent central nucleolus suggestive of prolymphocytes. On flow cytometry, these cells were positive for cytoplasmic CD3, CD2, CD5, CD7, CD4, and CD38 (dim) and were negative for CD1a and TdT and diagnosis of T-prolymphocytic leukemia was made.

Increased activated memory B-cells in the peripheral blood of patients with erythema nodosum leprosum reactions.

B-cells, in addition to antibody secretion, have emerged increasingly as effector and immunoregulatory cells in several chronic inflammatory diseases. Although Erythema Nodosum Leprosum (ENL) is an inflammatory complication of leprosy, the role of B- cell subsets has never been studied in this patient group. Therefore, it would be interesting to examine the contribution of B-cells in the pathogenesis of ENL. A case-control study design was used to recruit 30 untreated patients with ENL and 30 non-reactional lepromatous leprosy (LL) patient controls at ALERT Hospital, Ethiopia. Peripheral blood samples were obtained before, during and after treatment from each patient. Peripheral blood mononuclear cells (PBMCs) were isolated and used for immunophenotyping of B- cell subsets by flow cytometry. The kinetics of B-cells in patients with ENL before, during and after Prednisolone treatment of ENL was compared with LL patient controls as well as within ENL group. Total B-cells, mature B-cells and resting memory B-cells were not significantly different between patients with ENL reactions and LL controls before treatment. Interestingly, while the percentage of naive B-cells was significantly lower in untreated ENL patients than in LL patient controls, the percentage of activated memory B-cells was significantly higher in these untreated ENL patients than in LL controls. On the other hand, the percentage of tissue-like memory B-cells was considerably low in untreated ENL patients compared to LL controls. It appears that the lower frequency of tissue-like memory B-cells in untreated ENL could promote the B-cell/T-cell interaction in these patients through downregulation of inhibitory molecules unlike in LL patients. Conversely, the increased production of activated memory B-cells in ENL patients could imply the scale up of immune activation through antigen presentation to T-cells. However, the generation and differential function of these memory B-cells need further investigation. The finding of increased percentage of activated memory B-cells in untreated patients with ENL reactions suggests the association of these cells with the ENL pathology. The mechanism by which inflammatory reactions like ENL affecting these memory cells and contributing to the disease pathology is an interesting area to be explored for and could lead to the development of novel and highly efficacious drug for ENL treatment.

Development of Type 2, But Not Type 1, Leprosy Reactions is Associated with a Severe Reduction of Circulating and In situ Regulatory T-Cells.

Leprosy is frequently complicated by the appearance of reactions that are difficult to treat and are the main cause of sequelae. We speculated that disturbances in regulatory T-cells (Tregs) could play a role in leprosy reactions. We determined the frequency of circulating Tregs in patients with type 1 reaction (T1R) and type 2 reaction (T2R). The in situ frequency of Tregs and interleukin (IL)-17, IL-6, and transforming growth factor beta (TGF)-ß-expressing cells was also determined. T2R patients showed markedly lower number of circulating and in situ Tregs than T1R patients and controls. This decrease was paralleled by increased in situ IL-17 expression but decreased TGF-ß expression. Biopsies from T1R and T2R patients before the reaction episodes showed similar number of forkhead box protein P3+ (FoxP3+) and IL-17+ cells. However, in biopsies taken during the reaction, T2R patients showed a decrease in Tregs and increase in IL-17+ cells, whereas T1R patients showed the opposite: Tregs increased but IL-17+ cells decreased. We also found decreased expansion of Tregs upon in vitro stimulation with Mycobacterium leprae and a trend for lower expression of FoxP3 and the immunosuppressive molecule cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) in T2R Tregs. Our results provide some evidence to the hypothesis that, in T2R, downmodulation of Tregs may favor the development of T-helper-17 responses that characterize this reaction.

CD4+, CD8+, CD3+ cell counts and CD4+/CD8+ ratio among patients with mycobacterial diseases (leprosy, tuberculosis), HIV infections, and normal healthy adults: a comparative analysis of studies in different regions of India.

In this study, we estimated the CD4+, CD8+, CD3+ cell counts and the CD4/CD8 ratio among normal healthy controls (adults and children), leprosy patients (without any complications and during reactional states), TB patients (with and without HIV), and HIV-positive patients (early infection and full-blown AIDS) and correlated the changes with disease progression. In our study, it was observed that among adults, CD4+ cell counts ranged from 518-1098, CD8+ from 312-952, whereas CD4/CD8 ratio from 0.75-2.30. Among children, both CD4+ and CD8+ cells were more and the CD4/CD8 ratio varied from 0.91-3.17. With regard to leprosy patients, we observed that CD4+ and CD8+ cell counts were lower among PB (pauci-bacillary) and MB (multi-bacillary) patients. CD4/CD8 ratio was 0.99 ± 0.28 among PB patients while the ratio was lower, 0.78 ± 0.20, among MB patients. CD4+ cell counts were raised during RR (reversal reactions) and ENL (erythema nodosum leprosum) among the PB and MB patients whereas the CD8+ cell counts were lower among PB and MB patients. CD4/CD8 ratio doubled during reactional episodes of RR and ENL. Among the HIV-negative tuberculosis (TB) patients, both the CD4+ and CD8+ cell counts were found to be less and the CD4/CD8 ratio varied between 0.53-1.75. Among the HIV-positive TB patients and HIV-positive patients, both the CD4+ and CD8+ cells were very less and ratio drops significantly. In the initial stages of infection, as CD4+ counts drop, an increase in the CD8+ cell counts was observed and the ratio declines. In full-blown cases, CD4+ cell counts were very low, 3-4 to 54 cells, CD8+ cells from 12-211 and the ratio drops too low. This study is the first of its kind in this region of the country and assumes importance since no other study has reported the values of CD4+ and CD8+ T-lymphocyte counts among patients with mycobacterial diseases (leprosy and TB), HIV infections along with normal healthy individuals of the region, and correlation with clinical presentations of patients.

Diffuse alopecia areata is associated with intense inflammatory infiltration and CD8+ T cells in hair loss regions and an increase in serum IgE level.

BACKGROUND: Mechanism leading to an abrupt hair loss in diffuse alopecia areata (AA) remains unclear. AIMS: To explore the characteristics of diffuse AA and possible factors involved in its pathogenesis. METHODS: Clinical and laboratory data of 17 diffuse AA patients and 37 patchy AA patients were analyzed retrospectively. Serum IgE level was evaluated in all diffuse and patchy AA patients, as well as 27 healthy subjects without hair loss to serve as normal control. Univariate analysis was performed using Fisher's exact test and Wilcoxon rank-sum test. Associations between inflammatory cell infiltration and laboratory values were analyzed using Spearman rank correlation test. RESULTS: The mean age of patients with diffuse AA was 27 years with a mean disease duration of 1.77 months. All of them presented in spring or summer with an acute onset of diffuse hair loss preceded by higher incidence of scalp pruritus. Although no statistically significant difference on the incidence of atopic disease among three groups has been found, serum IgE level in diffuse AA was higher than that in healthy controls, but was comparable to that in patchy AA group. Histopathology of lesional scalp biopsies showed more intense infiltration comprising of mononuclear cells, eosinophils, CD3 + , and CD8 + T cells around hair bulbs in diffuse AA group than in patchy AA group. Moreover, IgE level in diffuse AA patients positively correlated with intensity of infiltration by mononuclear cells, eosinophils, and CD8 + T cells. CONCLUSIONS: Hypersensitivity may be involved in pathogenesis of diffuse AA. The acute onset of diffuse AA may be related to intense local inflammatory infiltration of hair loss region and an increase in serum IgE level.

Lower numbers of natural killer T cells in HIV-1 and Mycobacterium leprae co-infected patients.

Natural killer T (NKT) cells are a heterogeneous population of lymphocytes that recognize antigens presented by CD1d and have attracted attention because of their potential role linking innate and adaptive immune responses. Peripheral NKT cells display a memory-activated phenotype and can rapidly secrete large amounts of pro-inflammatory cytokines upon antigenic activation. In this study, we evaluated NKT cells in the context of patients co-infected with HIV-1 and Mycobacterium leprae. The volunteers were enrolled into four groups: 22 healthy controls, 23 HIV-1-infected patients, 20 patients with leprosy and 17 patients with leprosy and HIV-1-infection. Flow cytometry and ELISPOT assays were performed on peripheral blood mononuclear cells. We demonstrated that patients co-infected with HIV-1 and M. leprae have significantly lower NKT cell frequencies [median 0.022%, interquartile range (IQR): 0.007-0.051] in the peripheral blood when compared with healthy subjects (median 0.077%, IQR: 0.032-0.405, P < 0.01) or HIV-1 mono-infected patients (median 0.072%, IQR: 0.030-0.160, P < 0.05). Also, more NKT cells from co-infected patients secreted interferon-γ after stimulation with DimerX, when compared with leprosy mono-infected patients (P = 0.05). These results suggest that NKT cells are decreased in frequency in HIV-1 and M. leprae co-infected patients compared with HIV-1 mono-infected patients alone, but are at a more activated state. Innate immunity in human subjects is strongly influenced by their spectrum of chronic infections, and in HIV-1-infected subjects, a concurrent mycobacterial infection probably hyper-activates and lowers circulating NKT cell numbers.

Expression of the chemokine receptor CXCR4 on lymphocytes of leprosy patients

Leprosy is caused by Mycobacterium leprae, which induces chronic granulomatous infection of the skin and peripheral nerves. The disease ranges from the tuberculoid to the lepromatous forms, depending on the cellular immune response of the host. Chemokines are thought to be involved in the immunopathogenesis of leprosy, but few studies have investigated the expression of chemokine receptors on leukocytes of leprosy patients. In the present study, we evaluated 21 leprosy patients (M/F: 16/5) with a new diagnosis from the Dermatology Outpatient Clinic of the University Hospital, Federal University of Minas Gerais. The control group was composed of 20 healthy members (M/F: 15/5) of the community recruited by means of announcements. The expression of CCR2, CCR3, CCR5, and CXCR4 was investigated by flow cytometry on the surface of peripheral blood lymphocytes. There was a decrease in percentage of CD3+CXCR4+ and CD4+CXCR4+ lymphocytes in the peripheral blood of leprosy patients (median [range], 17.6 [2.7-41.9] and 65.3 [3.9-91.9], respectively) compared to the control group (median [range], 43.0 [3.7-61.3] and 77.2 [43.6-93.5], respectively). The percentage of CD4+CXCR4+ was significantly lower in patients with the tuberculoid form (median [range], 45.7 [0.0-83.1]) of the disease, but not in lepromatous patients (median [range], 81.5 [44.9-91.9]). The CXCR4 chemokine receptor may play a role in leprosy immunopathogenesis, probably directing cell migration to tissue lesions in tuberculoid leprosy patients.

Expression of the chemokine receptor CXCR4 on lymphocytes of leprosy patients.

Leprosy is caused by Mycobacterium leprae, which induces chronic granulomatous infection of the skin and peripheral nerves. The disease ranges from the tuberculoid to the lepromatous forms, depending on the cellular immune response of the host. Chemokines are thought to be involved in the immunopathogenesis of leprosy, but few studies have investigated the expression of chemokine receptors on leukocytes of leprosy patients. In the present study, we evaluated 21 leprosy patients (M/F: 16/5) with a new diagnosis from the Dermatology Outpatient Clinic of the University Hospital, Federal University of Minas Gerais. The control group was composed of 20 healthy members (M/F: 15/5) of the community recruited by means of announcements. The expression of CCR2, CCR3, CCR5, and CXCR4 was investigated by flow cytometry on the surface of peripheral blood lymphocytes. There was a decrease in percentage of CD3+CXCR4+ and CD4+CXCR4+ lymphocytes in the peripheral blood of leprosy patients (median [range], 17.6 [2.7-41.9] and 65.3 [3.9-91.9], respectively) compared to the control group (median [range], 43.0 [3.7-61.3] and 77.2 [43.6-93.5], respectively). The percentage of CD4+CXCR4+ was significantly lower in patients with the tuberculoid form (median [range], 45.7 [0.0-83.1]) of the disease, but not in lepromatous patients (median [range], 81.5 [44.9-91.9]). The CXCR4 chemokine receptor may play a role in leprosy immunopathogenesis, probably directing cell migration to tissue lesions in tuberculoid leprosy patients.

Vaccine for tuberculosis: up-regulation of IL-15 by Ag85A and not by ESAT-6.

IFN-γ is the most commonly measured cytokine released by the cells to define the cellular immune responses induced by the vaccine candidates for tuberculosis. IL-15 acts as a co-stimulator in IFN-γ production by NK cells and may therefore be important in the control of Mycobacterium tuberculosis that requires IFN-γ for clearance. The aim of the study is to determine whether Ag85A can also stimulate the innate immune response through the expression of IL-15, a cytokine that bridges the innate and adaptive immune systems. The expression of IL-15 was up regulated by about 4 fold in PPD+ healthy controls as compared with TB patients. Significantly higher expression of IL-15 mRNA in the Ag85A stimulated cells not only in PPD+ healthy controls but also in TB patients substantiates the use of Ag85A as a vaccine candidate over ESAT-6.

A histopathological study of cutaneous leishmaniasis in Sri Lanka.

UNLABELLED: INTRODUCTION; Cutaneous leishmaniasis is endemic in Sri Lanka. The immunopathogenesis of these lesions in Sri Lankans has not been documented. OBJECTIVES: To classify skin lesions into histological groups, to assess parasitic load, density of each inflammatory cell type and necrosis and to characterise the lymphocytic reaction in cutaneous leishmaniasis in comparison to leprosy. METHODS: Skin biopsies from 31 patients with demonstrable amastigotes in smears or tissue sections were studied. The lesions were classified by two independent observers into four distinct histological groups based on different cell types in the inflammatory infiltrate and formation of granulomata. Parasitic load and the presence of necrosis were recorded. Immunohistochemical staining for CD45RO and CD20 for counting T and B cells respectively was done. RESULTS: Histological groups of cutaneous leishmaniasis ranging from group I-IV were similar to that of the spectrum in leprosy ranging from lepromatous to tuberculoid leprosy. The histological groups from I-IV showed a significant inverse relationship with the mean parasitic index. Necrosis was not a prominent feature. The mean percentage of T cells in the histological spectrum from group I-IV in leishmaniasis was similar to the spectrum from lepromatous to tuberculoid leprosy. Mean percentage of T cells were 20.1% in group I, 20.5% in group II, 33.8% in group III and 47.8% in group IV. Lepromatous, borderline tuberculoid and tuberculoid leprosy had 21.3%, 33.4% and 48.0% T cells respectively. CONCLUSION: Cutaneous leishmaniasis is a spectral disease similar to leprosy. The mean percentage T cells from group I-IV were similar to those in the spectrum of leprosy and mean percentage B cells varied in a narrow range.

The human CD1-restricted T cell repertoire is limited to cross-reactive antigens: implications for host responses against immunologically related pathogens.

The repertoires of CD1- and MHC-restricted T cells are complementary, permitting the immune recognition of both lipid and peptide Ags, respectively. To compare the breadth of the CD1-restricted and MHC-restricted T cell repertoires, we evaluated T cell responses against lipid and peptide Ags of mycobacteria in leprosy, comparing tuberculoid patients, who are able to restrict the pathogen, and lepromatous patients, who have disseminated infection. The striking finding was that in lepromatous leprosy, T cells did not efficiently recognize lipid Ags from the leprosy pathogen, Mycobacterium leprae, or the related species, Mycobacterium tuberculosis, yet were able to efficiently recognize peptide Ags from M. tuberculosis, but not M. leprae. To identify a mechanism for T cell unresponsiveness against mycobacterial lipid Ags in lepromatous patients, we used T cell clones to probe the species specificity of the Ags recognized. We found that the majority of M. leprae-reactive CD1-restricted T cell clones (92%) were cross-reactive for multiple mycobacterial species, whereas the majority of M. leprae-reactive MHC-restricted T cells were species specific (66%), with a limited number of T cell clones cross-reactive (34%) with M. tuberculosis. In comparison with the MHC class II-restricted T cell repertoire, the CD1-restricted T cell repertoire is limited to recognition of cross-reactive Ags, imparting a distinct role in the host response to immunologically related pathogens.

Lesional T-cell subset in leprosy and leprosy reaction.

BACKGROUND: The T-cell-mediated immune response plays an important role in leprosy. The in situ proportion and pattern of distribution of T-cell subsets in leprosy skin lesions have been studied, but no conclusion could be drawn. METHODS: We used monoclonal antibodies for T-helper and T-suppressor surface antigen to define the nature of dermal infiltration in 17 cases of nonreactional leprosy and 20 cases of reactional leprosy. RESULTS: We found T helper admixed with T suppressor in an aggregated pattern in the granulomas of most cases of nonreactional leprosy and in type I reactional leprosy, but a diffuse infiltrate throughout the dermis of type II reactional leprosy. The T-helper/suppressor ratio was 1.68 in tuberculoid and 1.5 in lepromatous cases. The T-helper/ suppressor ratios of borderline tuberculoid (3.11) and type I reactional leprosy (2.54) were not statistically different. The T-helper/suppressor ratio of type II reactional leprosy (5.83) was statistically higher than nonreactional lepromatous cases. CONCLUSIONS: The alteration of the T-helper/suppressor ratio in our study is mainly due to the reduction of T-suppressor cells in the dermal infiltrates, especially in type II reactional leprosy. Further studies of T-suppressor functions may be important in the pathogenesis of leprosy.

Prognostic evaluation of cell mediated immunity in leprosy and correlation with clinicopathological status of leprosy patients.

Cell mediated immunity was studied in 50 patients of leprosy and 15 control volunteers, by estimation of peripheral blood lymphocytes (PBL), total rosette forming cells (TRFC) and active rosette forming cell (ARFC) counts in vitro. PBL, TRFC and ARFC counts were slightly but not significantly increased in patients of tuberculoid leprosy (TT) and muculoanaesthetic variant of tuberculoid leprosy as compared to control group. However, gradual decrease in T-cell subsets, occurred in borderline tuberculoid leprosy (BT) as compared to tuberculoid type (TT)-(p < 0.05). Significant decrease in lymphocytes and T-cell subsets was observed in midborderline leprosy (BB), (p < 0.01):borderline lepromatous leprosy (BL), (p < 0.001) and lepromatous subpolar and polar types (LL); (p < 0.001) as compared to control group. Mycobacterium leprae (M.leprae) were positive in BT-(20%); BB-(72.7%); BL-(83.2%) and LL-(100%). Delayed hypersensitivity reactions (DHR) revealed significantly increased lepromin positivity in TT (83.3%) and BT (80%) which decreased in BB (63.6%) and BL (50%). Lepromin test showed anergic state in LL group (28.5% positivity). Dinitrochlorobenzene (DNCB) skin test showed 100% positivity in TT group and controls while gradual significant decrease was observed from BT (p < 0.05) to LL scale (p < 0.001). Leprosy spectrum of Ridley and Jopling scale is directly co-related with inherent cell mediated immune status of the patients which has a significant prognostic role in treatment and long term management.

Phenotype and cytokine expression of intralesional cells in borderline leprosy.

We studied the cytokine profiles and cellular compositions in the lesions of borderline lepromatous (BL) and borderline tuberculoid (BT) leprosy patients in order to ascertain the immunological distinctions between these two groups. Using a modified, reliable, noninvasive, suction-induced blister technique to sample lesions, we determined that CD4+ T cells predominated in BT lesions; whereas CD8+ T cells predominated in BL lesions. However, the numbers of CD8+ per mm2 surface area of the lesion did not differ significantly between the two patient groups. In BT lesions, the elevation in the number of CD4+ cells was paralleled by the levels of soluble interleukin-2 (IL-2) receptor and soluble CD4 in the lesions. The CD4+:CD8+ ratio was 16:1 in BT lesions and 0.36:1 in BL lesions, although this ratio in the peripheral blood was similar in both groups. In addition, cells expressing the CD8 molecule dominated in the TCR-gamma delta subpopulation. The cytokine profiles in the lesions were not as distinctly different between BL and BT patients as were the cellular compositions. However, trends observed included elevated concentrations of IL-6 in BL lesions and elevated TNF-alpha levels in BT lesions.