Biochemical, immunological and genetic studies in leprosy. II. Profile of immunoglobulins, complement components and C-reactive protein in sera of leprosy patients and healthy controls.

Various classes of immunoglobulins (IgA, IgM, IgG, IgD and IgE), complement components (C3 and C4) and C-reactive protein (CRP) were estimated in sera from normal healthy controls and leprosy (lepromatous and tuberculoid) patients from Ethiopia. Higher levels of IgA, IgM, IgG and IgD were found in lepromatous leprosy compared with normal healthy people while in tuberculoid leprosy only IgM, IgG and IgD levels were increased. Borderline leprosy patients showed increase in IgG level only. Although an increase in IgE was noted in lepromatous leprosy, it was not significant; the variations in IgE levels could be due to different socioeconomic background and exposure to intestinal parasites. C3 component was significantly reduced in leprosy patients compared with healthy controls while no difference in C4 component was observed. The results point towards an involvement of the "alternate pathway". A positive test against C-reactive protein antiserum was given by about 20% of the normal healthy controls while more than 60% lepromatous and tuberculoid leprosy patients were CRP positive. The results are discussed in relation to the status of immunoglobulins and complement components in leprosy and possible factors (environmental and genetic) which might affect them.     

Serum antibodies against peripheral nervous system antigens in leprosy.

Since antibodies against peripheral nervous system (PNS) antigens may play a pathogenetic role in the mechanism of nerve damage in leprosy, sera from leprosy patients and contacts were investigated for anti-PNS antibodies by ELISA and immunoblot. In ELISA, elevated anti-PNS antibody levels were detected in 4 of 98 (4.1%) leprosy patients (4 of 52, 7.7%, lepromatous leprosy patients), in 1 of 28 (3.6%) contacts, and in 1 of 18 (5.6%) normal controls. There was no correlation between anti-PNS antibody levels and the bacterial index or neuropathy in leprosy. Immunoblot with a sample of six leprosy and five control sera showed that the antigenic binding pattern (mainly within the 100-200-kDa region) was very similar in patients and controls. Staining intensity, however, appeared to be higher with the leprosy sera than with the control sera. IgM and IgG were found to contribute to the staining pattern: IgM in the 150-200-kDa range, IgG with multiple bands between 25 kDa and 200 kDa. Thus, the presence and levels of serum anti-PNS antibodies in leprosy appear to be unrelated to parameters of disease activity, neuropathy in particular, and do not seem to be critically involved in the pathogenesis of nerve damage.     

Biochemical, immunological and genetic studies in leprosy. I. Changes in serum lactate dehydrogenase isoenzymes, creatine phosphokinase and aldolase activity in different forms of leprosy.

Serum lactate dehydrogenase isoenzymes, creatine phosphokinase and aldolase activity were determined in healthy control subjects and in lepromatous and tuberculoid leprosy patients from Ethiopia. Sera from lepromatous patients showed a higher total LDH activity compared with control subject. The values for tuberculoid leprosy patients were similar to those of controls. Sera from normal healthy controls showed a higher proportion of LDH-H form (72%) while lepromatous leprosy patient's sera exhibited a higher proportion of LDH-M form (55%). Tuberculoid leprosy patients showed a pattern similar to that of healthy controls. A possible significance of these observations is discussed. No significant variations were observed in fructose-1,6-diphosphate aldolase activity within the different types of disease and controls. Although creatine phosphokinase levels in different types of leprosy decreased significantly from those of normal healthy, it falls within the reported variation of the activity in normal sera.     

Protective effect of intradermal BCG against leprosy; a case-control study in central Brazil.

A case-control study was undertaken to evaluate the protective efficacy of intradermal BCG against leprosy in a high-endemic area of leprosy in central Brazil. Sixty-two cases and 186 controls were included in the study. Cases were all newly diagnosed leprosy patients under 16 years of age attending an outpatient health service, and all of them were schoolchildren. Three controls under 16 years old, frequency matched by sex and age group, were selected from schools geographically located in the area from which the cases came. The presence of BCG was negatively associated with leprosy, indicating a 5.3 risk of leprosy for those nonvaccinated and protective efficacy of 81%. Paucibacillary patients were more likely to have a BCG scar than multibacillary patients.     

Influence of environmental mycobacteria on the prevalence of leprosy clinical type

A comparison was made of antibody levels to 16 environmental mycobacteria in leprosy patients and healthy controls. Significant differences in response were found between patients and controls from an area of Zimbabwe with predominantly lepromatous leprosy when compared to an area where more tuberculoid cases were found. The results obtained suggest that exposure to some environmental mycobacteria may influence the type of leprosy developed by susceptible individuals.     

Study of apoptosis in skin lesions of leprosy in relation to treatment and lepra reactions

In leprosy on treatment, one factor contributing to the healing of skin lesions with minimal fibrosis may be apoptosis of inflammatory cells, even though apoptosis is sparse in leprosy as compared to tuberculosis. The degree of apoptosis in skin lesions of leprosy was studied by histopathologic examination (HPE) and by DNA fragmentation and electrophoresis. The effect of various parameters on apoptosis was noted in untreated disease, during treatment at 3 and 6 months, and in lepra reactions in different parts of the spectrum of leprosy. Of the 31 patients, 13 had paucibacillary (PB) and 18 multibacillary (MB) disease. Twenty one patients were in reaction: 16 had type 1 reaction and 5 had type 2 reaction. The controls included patients with non-granulomatous skin diseases; there were no normal controls, and no separate controls for cases with reaction. Apoptosis occurred more frequently in patients with leprosy as compared to the controls. In both PB & MB lesions, apoptosis was observed to increase progressively with treatment at 3 and 6 months, and was more prominent in the MB cases at 6 months of treatment. When lesions in either type 1 or type 2 reaction were compared to lesions not in reaction, a significant increase in apoptosis (p = 0.014) was found only in lesions with type 2 reaction and those which were at 6 months of treatment. The type of treatment regimen, or oral steroids given for reactions, did not significantly alter the degree of apoptosis. Our observations indicate that increased apoptosis is present in leprosy lesions and that in leprosy it progressively increases with anti-leprosy treatment up to 6 months. If the process of apoptosis in skin lesions is followed up for a longer period of time, the degree of apoptosis may be expected to decline. The study of apoptosis may help to understand the mechanism of clearance of bacilli and resolution of granulomas in leprosy patients.     

A study of serum fibrinolytic activity in erythema nodosum leprosum (ENL)

Fibrinolytic activity was studied in 31 patients of leprosy and 10 healthy controls. Fibrinolytic activity was found to be significantly decreased in patients with erythema nodosum leprosum, compared to those with uncomplicated lepromatous leprosy, who in turn showed lowered activity compared to patients with tuberculoid form of leprosy and controls. The severity of ENL correlated very well with decrease in fibrinolytic activity. Fibrinolytic activity was improved to levels obtained in uncomplicated lepromatous leprosy after the subsidence of reaction. So it would seem reasonable to suggest that estimation of fibrinolytic activity provides a reliable criteria to quantitate the severity of erythema nodosum leprosum.     

Antibodies to sulfatide in leprosy and leprosy reactions.

Antibodies to sulfatide have been reported in various demyelinating peripheral polyneuropathies. We have investigated the diagnostic value of these antibodies in leprosy. Anti-sulfatide IgM in leprosy patients was not significantly elevated. High anti-sulfatide IgG titers were observed in individuals from endemic areas, irrespective of their leprosy status, while western European controls were negative. No significant correlation was found between IgM or IgG antibody titers and leprosy classification, although multibacillary patients had higher anti-sulfatide IgM titers than paucibacillary patients. In addition, 23 patients developing leprosy reactions were followed longitudinally. Antibody titers in these patients fluctuated slightly during the follow-up period. There was no association with the occurrence of leprosy reactions or treatment. Thus, IgG titers against sulfatides are high in both leprosy patients and healthy controls in endemic areas, whereas such antibodies are not found in western European controls, suggesting that these antibodies are induced by environmental factors, such as microorganisms.     

Palmar flexion creases and dermatoglyphics in leprosy patients

Palmar configurations of 115 male and 48 female leprosy patients were compared with 536 males and 426 female normal individuals of the same population. The data was derived from Nekararu (weavers) castes of Karnataka State, India. Among flexion creases, the single radial base crease (SRBC) especially showed more association with leprosy in both male and female patients than their respective controls. Among dermatoglyphics, only C-line types are significantly different in male leprosy patients as compared to their controls. The female patients also showed more C-absent lines than the control group. The susceptibility to bacterial infection may be due to some biologic deficiency which warrants continued investigation on a broader and more intensive basis.     

Human leukocyte antigen and leprosy: study in northern Louisiana and review

We examined the relationship of human leukocyte antigen (HLA) phenotype to leprosy in six sporadic cases in northern Louisiana and in the world literature through pooling of the results of several studies. We found that HLA antigens DR2 and DQwl were associated with leprosy in the six cases in northern Louisiana (relative risks, 4.57 for DR2 and 4.53 for DQwl), but the results are not statistically significant. We pooled the Louisiana study and other population studies of HLA and leprosy. The results of the pooling show DR2 and DQwl to be associated with leprosy (relative risks, 2.65 for DR2 and 2.73 for DQwl), and these associations are highly statistically significant (P less than 1 x 10(-8) for DR2 and P = 3.6 x 10(-8) for DQwl). Further, we pooled studies of lepromatous leprosy patients vs. controls and studies of tuberculoid leprosy patients vs. controls and found that DR2 and DQwl are associated with both the lepromatous and the tuberculoid forms of leprosy and that these associations are statistically significant. We consider the associations of DR2 and DQwl in these population studies to be evidence for an HLA-associated genetic influence on susceptibility to leprosy.     

Serum immunoglobulins, including IgG subclasses, in Vietnamese leprosy patients

Levels of serum immunoglobulins were measured in healthy Vietnamese and in leprosy patients. Healthy Vietnamese had higher levels of IgG, IgA, IgM, and IgE than did healthy Dutch controls, as well as higher levels of three of the four subclasses of IgG (IgG1, IgG2, IgG3). Lepromatous leprosy patients had significant increases in all classes and subclasses of immunoglobulins, except for IgG2, in comparison with local controls. Tuberculoid leprosy patients had more IgG1, IgG3, and IgG4 than did local controls and had higher total IgG levels. The patients had no increase in autoantibodies against tissue antigens compared to local or Dutch controls.     

Immunologic defects in leprosy patients. I. Evidence of immune aberration of suppressor-T lymphocytes in lepromatous leprosy

Immunoregulation in various types of leprosy patients was evaluated in vitro using peripheral blood mononuclear leukocytes (PBML) stimulated with phytohemagglutinin-P (PHA-P) or concanavalin A (ConA) for a cell-mediated immune (CMI) assay or pokeweed mitogen (PWM) for a humoral-mediated immune (HMI) assay. The immune responses were evaluated by a lymphocyte transformation test (LTT) and lymphocyte-mediated cytotoxicity (LMC) for the immunoregulation of CMI, and a reverse hemolytic plaque assay for measuring the plaque-forming cells (PFC) and a sandwich ELISA for measuring IgG concentrations for the immunoregulation of HMI. In LTT with PHA-P or ConA, the mean of the normal controls was not significantly different from the means of the untreated LL, BL, BB, BT, and TT leprosy patients. However, a wide variation of LTT results from BT to LL patients was noted: the LTT results of TT patients and normal controls were less variable. A similar pattern of immune responses was noted when studied by LMC in untreated LL, BL, BB, BT, and TT leprosy patients and normal controls. When the untreated patients and normal controls were studied for PFC, using PBML stimulated with PWM, a very similar pattern of PFC was obtained with the different types of leprosy patients. The immunoregulatory role of lymphocytes in leprosy patients was further evaluated by cell mixing cultures. ConA-stimulated PBML from lepromatous leprosy patients were mixed with normal PBML and then stimulated with PHA-P.(ABSTRACT TRUNCATED AT 250 WORDS)     

Clinical and immunological assessment of periodontal disease in Japanese leprosy patients

Periodontitis is a chronic inflammatory disease caused by the infection of periodontopathic bacteria in dental plaque. However, an individual's susceptibility to this disease appears to be associated with multiple genetic factors, as seen in the case of leprosy. In order to gain a better understanding of the pathophysiology of periodontal disease in subjects with leprosy, we investigated the clinical features of periodontitis and the immunological responses against periodontopathic bacteria in 382 subjects with a history of leprosy and 451 age-matched control subjects. The prevalence of periodontitis and the degree of periodontal pocket depth were found to be significantly higher in leprosy patients than in age-matched controls. Furthermore, a comparison of the clinical parameters of lepromatous leprosy (L-lep) and tuberculoid leprosy (T-lep) patients showed that the probing pocket depth of L-lep patients with periodontal disease was significantly higher than that for T-lep patients. In contrast, serum IgG titers against Porphyromonas gingivalis in L-lep patients were significantly lower than in T-lep patients. These results imply that L-lep patients show more severe periodontal disease than T-lep patients or age-matched control subjects, and that low humoral immunity against P. gingivalis might be one of the genetic factors determining periodontal disease susceptibility in leprosy patients.     

Impairment of fingertip vasomotor reflexes in leprosy patients and apparently healthy contacts.

Fingertip blood-flow velocity and its control by vasomotor reflexes were studied in leprosy patients and in healthy controls with a laser Doppler flowmeter. In newly registered patients, the flow was significantly lower than in the healthy controls, and even lower values were recorded in the long-standing patients with lower limb ulcers and/or deformity. The newly registered patients showed substantially impaired vasomotor reflex responses in the fingertips to cold challenge of the opposite hand or deep inspiratory gasp. Low blood flow and impairment of vasomotor reflexes were more prominent in those leprosy patients who showed clinical evidence of neuropathy and/or histological evidence of reaction in a punch biopsy of leprosy skin lesions. This aspect of dysautonomia to cold challenge was particularly prominent in apparently healthy, fully treated ex-patients. There was an unexpectedly high prevalence of impairment of vasomotor reflexes in newly registered and apparently healthy, adequately treated leprosy patients. The method is very sensitive, and it remains to be established whether the lesions it detects are nonprogressive residues, or previous nerve damage, or an indication of on-going nerve damage. A minority of leprosy contacts showed impairment of vasomotor reflexes. Those with two or more affected fingers were more likely to have had a higher level of exposure to Mycobacterium leprae than those with one or no affected fingers. The cause of this unexpected impairment of fingertip vasomotor reflexes in a minority of leprosy control workers has not yet been determined.     

Leprosy and hepatitis B virus markers: incidence of HBsAg and HBeAg in Somalian patients.

Serum samples from 222 Somalian patients, 135 with the lepromatous form of leprosy and 87 with the tuberculoid form of the disease, were examined for the presence of the surface antigen (HBsAg), the "e" antigen (HBeAg), and their corresponding antibodies (anti-HBs and anti-e). HBsAg was present in 24.4% of the LL cases and in 11.5% of the TT patients while anti-HBs was found respectively in 46.6% and 58.6%. The e-antigen was not found in any case of leprosy; anti-e was detected in 8.1% of the LL patients and in 3.5% of the TT cases. The rate of HBV seropositivity (HBsAg plus anti-HBs) was the same in the LL patients (71.1%) and in the TT patients (70.1%) and that could reflect the conditions of life in their closed community. The analysis of results obtained in Somalia has shown the presence of a difference in the distribution of HBsAg among leprosy patients, with an increased antigenemia in the lepromatous form which was statistically significant (p less than 0.05). No differences, however, were found between the leprosy patients and healthy controls. These observations seem to indicate that patients with lepromatous leprosy do not have an increased susceptibility to infection by hepatitis B virus.     

Pituitary-gonadal hormones and interleukin patterns in leprosy

The functional status of pituitary-gonadal hormones and their relationship to the pattern of inflammatory cytokines in the lepromatous (LL/BL) and tuberculoid (TT/BT) poles of leprosy were investigated. Gonadotropins [luteinizing hormone (LH) and follicle-stimulating hormone (FSH)], interleukin (IL)-1beta, IL-6, tumour necrosis factor (TNF)-alpha and C-reactive protein (CRP) concentrations and erythrocyte sedimentation rate (ESR) were significantly higher in LL/BL leprosy patients than in controls and were not different from controls in TT/BT patients. LH and FSH were positively correlated with IL-1beta, IL-6 and TNF-alpha, and CRP concentrations and ESR. Testosterone plasma levels were significantly decreased in LL/BL patients and not different in TT/BT patients compared with controls. In addition, testosterone levels were inversely correlated with IL-6 and TNF-alpha. Prolactin plasma levels of both LL/BL and TT/BT patients were not different when compared with those of controls. There was a significant positive correlation between IL-6 and TNF-alpha plasma levels and ESR and CRP concentrations. IL-1beta was positively correlated with ESR but not with CRP. The significant correlations between gonadotropins and testosterone and cytokines in leprosy patients suggest that cytokines may have a direct influence at testicular level and may be of pathogenetic significance in leprosy and in other inflammatory states involving reproductive dysfunction.     

Natural killer (NK) cell activity and reversal reaction in leprosy

Two studies were conducted to assess natural killer (NK) cell activity in leprosy patients and healthy Ethiopian controls. The first study tested 26 untreated leprosy patients across the spectrum of the disease. It was found that lepromatous leprosy and all untreated, nonreactional patients had lower NK activity than healthy controls. However, patients presenting with reversal reaction (RR) had NK activity within the normal range. Heterogeneity was particularly marked in the NK activity of borderline patients. In the second study, NK cell activity was assessed in treated borderline tuberculoid leprosy (BT) patients. There were 30 patients with a history of RR and 27 BT patients without such a history (NR). All patients had had at least 3 years of dapsone treatment and 6 months of multidrug therapy. There were 26 control subjects. NK activity was higher in controls than in patients only at one effector:target (E:T) ratio tested, but NK cells from the BT patient group appeared to be more "aggressive" in that there was significantly (p less than 0.001) less reduction of activity with dilution of effector cells. There were no significant differences in NK activity between RR and NR patients. The NK activity of NR patients was positively correlated with the size of induration of the lepromin response. We conclude that higher NK activity in acute RR would appear to be a consequence rather than a cause of reversal reactions.     

Serum immunoglobulins in leprosy.

Serum immunoglobulins were quantitated by radial immunodiffusion in 25 cases each of tuberculoid and lepromatous leprosy. Immunoglobulins estimated from 50 normal healthy adults were the control. Serum IgG was markedly raised in both tuberculoid (mean 2420 mg/dl) and lepromatous leprosy (mean 2493 mg/dl) when compared with the controls (mean 1288 mg/dl) and the difference was significant (p less than 0.01). However the difference in serum IgM and IgA levels in cases as compared to controls were not statistically significant. Serum IgM was slightly raised, the mean values obtained being 222 mg/dl in tuberculoid leprosy, 221 mg/dl in lepromatous leprosy and 202 mg/dl in control. Serum IgA was reduced in lepromatous leprosy (mean 129 mg/dl) as compared to the controls (mean 168 mg/dl) and the cases of tuberculoid leprosy (mean 165 mg/dl). The range of values obtained in both groups of patients showed greater scatter than the controls and a few cases of both forms of leprosy showed very low values of both serum IgA and IgM.     

Serum pseudocholinesterase variants in Mexican-born patients with lepromatous leprosy

No difference in the distribution of serum pseudocholinesterase variants could be found in lepromatous leprosy patients as compared with controls. The variety of reported relationships of pseudocholinesterase variants in leprosy suggests that only in some populations is a locus regulating pseudocholinesterase genetically linked to a hypothetical locus regulating susceptibility to leprosy.     

Haptoglobulin phenotypes in leprosy

Haptoglobulin phenotyping was carried out in fifty controls and in thirty five leprosy patients. In controls the incidence Hp phenotypes 2-2, 2-1 and 2-1 (Mod) is 76%, 16% and 8% respectively. In leprosy patients, the incidence of phenotypes 2-2, 2-1, 1-1 and 0-0 is 77%, 11%, 3% and 9% respectively. The incidence of phenotype 2-2, 1-1 and 0-0 is more in leprosy patients than in controls and is significant (p less than 0.05). In none of the leprosy patients phenotype 2-1 (Mod) was recorded.