Immunological status of ENL (erythema nodosum leprosum) patients: its relationship to bacterial load and levels of circulating IL-2R.

Recent data suggest that the clinical course of reactional states in leprosy is closely related to the cytokine profile released locally or systemically by the patients. In the present study, patients with erythema nodosum leprosum (ENL) were grouped according to the intensity of their clinical symptoms. Clinical and immunological aspects of ENL and the impact of these parameters on bacterial load were assessed in conjunction with patients' in vitro immune response to mycobacterial antigens. In 10 out of the 17 patients tested, BI (bacterial index) was reduced by at least 1 log from leprosy diagnosis to the onset of their first reactional episode (ENL), as compared to an expected 0.3 log reduction in the unreactional group for the same MDT (multidrug therapy) period. However, no difference in the rate of BI reduction was noted at the end of MDT among ENL and unreactional lepromatous patients. Accordingly, although TNF-alpha (tumor necrosis factor) levels were enhanced in the sera of 70.6% of the ENL patients tested, no relationship was noted between circulating TNF-alpha levels and the decrease in BI detected at the onset of the reactional episode. Evaluation of bacterial viability of M. leprae isolated from the reactional lesions showed no growth in the mouse footpads. Only 20% of the patients demonstrated specific immune response to M. leprae during ENL. Moreover, high levels of soluble IL-2R (interleukin-2 receptor) were present in 78% of the patients. Circulating anti-neural (anti-ceramide and anti-galactocerebroside antibodies) and anti-mycobacterial antibodies were detected in ENL patients' sera as well, which were not related to the clinical course of disease. Our data suggest that bacterial killing is enhanced during reactions. Emergence of specific immune response to M. leprae and the effective role of TNF-alpha in mediating fragmentation of bacteria still need to be clarified.

Autoantibodies in leprosy sera.

Our objective was to assess the prevalence of autoantibodies in patients with leprosy. Forty-one cases of lepromatous leprosy were studied. For the detection of autoantibodies we used the Elisa technique using the following purified antigens in an Elisa assay: dsDNA, ssDNA, histone, mitochondria, RNA, RNP, SS-A, SS-B, Sm, Scl-70, Anca C, Anca P and the cardiolipin complex. As a "cut off" point we used values shown on previous studies to differentiate normal from elevated values. Antibodies to SS-B, mitochondria and cardiolipin were the most prevalent in our study. Antimitochondrial antibodies distinct from those seen in primary biliary cirrhosis and antiphospholipid antibodies with variable ligand activity to B2GIP are frequent in the sera of leprosy patients.

Anticardiolipin antibodies in infections are heterogenous in their dependency on beta 2-glycoprotein I: analysis of anticardiolipin antibodies in leprosy.

We studied the effect of beta 2-GPI on binding of antibodies in sera from patients with leprosy and patients with the antiphospholipid syndrome (APS) to CL in enzyme-linked immunosorbent assays (ELISAs). Increased levels of IgG aCL were detected in 59 of 61 leprosy patients' sera by the standard aCL-ELISA in the presence of bovine beta 2-GPI and in 60 of the 61 leprosy patients' sera by the modified aCL-ELISA without beta 2-GPI. When tested by both aCL-ELISAs on the same plate, 10/31 leprosy sera and 9/10 APS sera bound better in the standard aCL-ELISA, 16/31 leprosy sera bound better in the modified aCL-ELISA and in five leprosy and one APS sera the difference was not significant. A dose-dependent enhancing effect of beta 2-GPI on the leprosy and APS sera binding to CL was confirmed using purified human beta 2-GPI. Enhanced binding was seen if beta 2-GPI was added either before or together with the test serum. In 11/61 leprosy sera increased levels of IgG antibodies against beta 2-GPI were found by ELISA. Leprosy anti-beta 2-GPI antibodies appear to be a separate antibody population recognizing only beta 2-GPI adsorbed on the ELISA plate. These results demonstrate heterogeneity of leprosy aCL with respect to their beta 2-GPI requirement for binding to CL.

Antimitochondrial (pyruvate dehydrogenase) antibodies in leprosy.

Sera from 69 patients with leprosy but without liver involvement were assayed for the presence of mitochondrial pyruvate dehydrogenase (PDH)-specific autoantibodies by enzyme-linked immunoabsorbent assay (ELISA), immunoblotting using PDH as an antigen and by enzymatic inhibition test. Twenty-seven of the leprosy serum samples (39.1%) were found to react with PDH by ELISA. However, unlike sera from primary biliary cirrhosis (PBC) patients, none of these were able to inhibit the PDH enzymatic activity. By immunoblotting, it was found that only 2 of the 27 positive sera recognized the 74-kD protein of the PDH complex, which is recognized by sera of most PBC patients. The antimitochondrial antibodies in lepra most probably recognize different epitopes than those in PBC. These findings may indicate that anti-PDH autoantibodies in patients with leprosy may arise by polyclonal B cell stimulation and may represent natural anti-PDH autoantibodies.

DMSO and colchicine therapy in amyloid disease.

There is no specific therapy for primary amyloidosis, and acquired generalised amyloidosis can be treated only if the underlying disease is eliminated. In this study we have investigated the role of colchicine therapy in primary amyloidosis, and dimethylsulphoxide (DMSO) in leprosy associated secondary amyloidosis. No effect on creatinine clearance or 24 h proteinuria could be observed in the patients with primary amyloidosis. In the DMSO group renal function was considerably improved in 3 patients with moderate renal failure but not in those with severe renal impairment (creatinine clearance less than 10 ml/min). Serum SAA determinations were not particularly informative. These findings point to a beneficial effect of DMSO in human secondary amyloidosis when given at an early stage of renal involvement.

Peripheral blood monocyte function in leprosy patients.

The activities of monocytes from lepromatous (LL) and tuberculoid (TT) leprosy patients were studied in a variety of in vitro systems. In assays of receptor activity, increased densities of Fc and C3b receptor sites were observed in monocytes of LL and TT patients as compared to normals. No differences were observed between the polar forms of the disease. Similar results were obtained in the nitroblue tetrazolium (NBT) reduction test. Glucosamine incorporation by monocytes from LL and TT patients was not significantly different from that by monocytes from normal controls. A diminished monocyte spontaneous migration and chemotactic activity to lymphocyte derived chemotactic factor (LDCF) was found in both forms of the disease. Plasma inhibitory factor of monocyte chemotaxis was more evident in the lepromatous form of the disease.

SAA amyloid protein levels in amyloid-prone chronic inflammatory disorders. Lack of association with amyloid disease.

Serum amyloid protein A (SAA) levels were evaluated by a sensitive radioimmunoassay technique in leprosy, juvenile rheumatoid arthritis and chronic osteomyelitis. SAA was elevated in all 3 groups of patients. The level in each of the patient groups did not reflect the presence of secondary amyloidosis. Our study suggests that serum SAA protein levels should not be considered a routine diagnostic test in patients with chronic inflammatory diseases prone to the development of amyloid disease.

Serum amyloid protein SAA, C-reactive protein and lysozyme in leprosy.

Serum amyloid protein (SAA) appears to be the precursor of amyloid protein AA, the non-immunoglobulin fibril protein of secondary amyloidosis. Since amyloidosis is known to occur in high frequency associated with lepromatous leprosy (LL), we have examined the SAA levels in untreated LL patients and compared them to the levels observed in patients with tuberculoid leprosy (TT) and a large number observed in healthy controls. We found that SAA is markedly elevated in LL when compared to TT and controls. No clear correlation could be established with C-reactive protein, a well-documented acute phase reactant, or serum lysozyme levels that reflect the presence of monocyte activity. This study showed that SAA levels in leprosy do not appear to be a reflection of inflammatory activity or monocyte turnover. Whether amyloidosis will be more prevalent in patients who have higher SAA levels remains to be determined.