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Biomedical subjects

M Harboe

Publications and source records attributed to M Harboe.

At least 145 records · Page 8Linked to original sources

In vitro stimulation of lymphocytes in leprosy patients, healthy contacts of leprosy patients, and subjects not exposed to leprosy. Comparison of an antigen fraction prepared from Mycobacterium leprae and tuberculin-purified protein derivative.

In vitro lymphocyte stimulation was performed on peripheral blood lymphocytes from 48 leprosy patients, 15 healthy contacts of leprosy patients, and 16 normal controls who lived in a leprosy-free area and who had not been exposed to leprosy. Tuberculin PPD and an antigen fraction. MLW 1, prepared from M. leprae, were used as stimulants. The MLW 1 preparation contained one antibody-precipitable component when tested in crossed immunoelectrophoresis against a polyvalent anti-M. leprae immunoglobulin preparation, namely the ML 7 antigen. MLW 1 induced strong lymphocyte responses in patients with tuberculoid leprosy and healthy contacts of leprosy patients, but only a weak or no responses in lepromatous leprosy patients and non-exposed controls. A marked depression of the response to tuberculin PPD was observed in lepromatous leprosy patients. The specificity of the MLW 1 antigen is discussed, and a new estimator of specific lymphocyte stimulation, the delta cpm', is introduced.

Adolescent↗

Thymus dependent lymphocytes in leprosy. I. T lymphocyte subpopulations defined by monoclonal antibodies.

Monoclonal antibodies recognizing different human T lymphocyte subpopulations were used to characterize peripheral blood T lymphocytes in patients with leprosy. An increase in the suppressor T lymphocyte subpopulation was seen only in lepromatous leprosy (BL-LL) patients. In contrast, patients who had erythema nodosum leprosum (ENL) showed a disturbance in immunoregulation seen as a decrease of the suppressor cell percentage and manifested by an increase in in vitro lymphoproliferative responses to both PPD and PHA. This imbalance was seen to normalize as patients improved clinically. There was no deviation from the normal values of the total T lymphocyte population. It is suggested, therefore, that ENL may be associated with an acute imbalance of T lymphocyte subpopulations. Since the suppressor T lymphocyte identified by the mononuclear antibody used is antigen nonspecific, the significance of these suppressor cells in the pathogenesis of leprosy remains unclear.

Antibodies, Monoclonal↗

Class specific anti-Mycobacterium leprae antibody assay in lepromatous leprosy (BL-LL) patients during the first two to four years of DDS treatment.

Previously, a slight decrease in antibodies against M. leprae antigen 7 was demonstrated after one year of dapsone (DDS) treatment in 14 of 15 patients with lepromatous (BL-LL) leprosy. The same patients have now received DDS from 11/2 to 4 years (median 3 years) and sera taken at the start, during, and at the end of the observation period have been retested for antibodies against M. leprae antigen 7 by radioimmunoassay and tested for IgA-, IgM-, and IgG-anti-M. leprae antibody activity by solid phase radioimmunoassay. Both IgA- and IgG-anti-M. leprae antibody activity and the activity of antibodies against M. leprae antigen 7 showed a decrease in activity after three years of DDS treatment to a median value of about one third of the activity in the sera taken at the start of the study. A smaller but significant decrease in IgM-anti-M. leprae antibody activity could be demonstrated. A transient increase in antibody activity (both measured by RIA and sRIA) could be demonstrated and related to reactions (reversal reaction and ENL) in five patients. No significant correlation could be found when IgA-, IgM-, and IgG-anti-M. leprae antibody activity was compared with antibodies against M. Leprae antigen 7 in individual sera.

Antibodies, Anti-Idiotypic↗

IgA, IgM and IgG anti-M. leprae antibodies in babies of leprosy mothers during the first 2 years of life.

IgA, IgM and IgG anti-M. leprae antibody activity was estimated by solid phase radioimmunoassay in repeated serum samples from cord sera to sera taken 2 years after birth from 29 babies of mothers with lepromatous leprosy (Group 1) and 16 babies of mothers with tuberculoid leprosy and non-leprosy control mothers (Group 2). IgA anti-M. leprae antibody activity could be detected in 30% and IgM anti-M. leprae antibody activity in 50% of cord sera from Group 1, but not in any of the cord sera from Group 2. After birth, there was a significantly higher increase of IgA and IgM anti-M. leprae antibody activity in sera taken 3-6 months after birth from babies of Group 1 compared to Group 2, but the IgA and IgM activity in sera taken after 6 months of age showed the same increase in the two groups. IgG anti-M. leprae antibody activity showed a marked decrease in sera from both Groups 1 and 2 taken 3-6 and 6-9 months after birth compared to the activity in the cord sera. No increase of the IgG activity could be demonstrated even in sera taken 15-24 months after birth in any of the two groups. These findings are discussed in relation to possible transfer of M. leprae bacilli across the placenta, the influence of M. leprae and other mycobacteria exposure on the antibody activity, the poor IgG anti-M. leprae antibody response and subclinical leprosy infection in babies exposed to leprosy below 2 years of age.

Age Factors↗

Immunoglobulin class specific antibodies to M. leprae in leprosy patients, including the indeterminate group and healthy contacts as a step in the development of methods for sero-diagnosis of leprosy.

IgA, IgM and IgG anti-M. leprae antibody activity was quantitated by solid phase radioimmunoassay in groups of untreated leprosy patients throughout the spectrum, in lepromatous leprosy patients treated for more than 10 years, in an indeterminate leprosy group, and in a non-leprosy control group. IgA, IgM and IgG anti-M. leprae antibody activity increased from the group of healthy individuals exposed to M. leprae but without clinical signs of leprosy to tuberculoid (BT and BT/TT) and further to lepromatous (BL to LL) leprosy. There was a considerable overlap in IgA antibody activity, while the overlap between controls and tuberculoid and lepromatous leprosy was less than 20% in the IgM and IgG assays. After more than 10 years of treatment, the IgG anti-M. leprae activity had decreased markedly, whereas there was less effect in the IgA assay and no significant change in the IgM assay. In contrast to earlier findings, the group of 'strictly indeterminate leprosy' showed signs of an active humoral immune response against M. leprae. The IgM anti-M. leprae activity was higher in indeterminate leprosy than in the control group with virtually no overlap. IgA anti-M. leprae was higher in indeterminate leprosy, but with considerable overlap with the controls. No difference between these two groups was found in the IgG assay. The results are discussed in relation to the value of the various immunoglobulin specific anti-M. leprae assays for different purposes, including development of techniques for sero-diagnosis of leprosy.

Antibodies, Bacterial↗

Demonstration of mycobacterial antigens in leprosy tissues.

Biopsies from 69 patients with leprosy were stained to demonstrate mycobacterial antigens using immunoperoxidase methods. The same biopsies were cut and stained using Fite-Faraco, TRIFF and hematoxylin-eosin for classifying the patients and to demonstrate mycobacteria. Since M. leprae and BCG show extensive antigenic cross reactions, anti-BCG antibodies were used as primary antisera to demonstrate cross-reacting antigens of M. leprae. Cross-reacting mycobacterial antigens were, thus, found in all LL and BL leprosy patients. Eight out of 10 patients with indeterminate leprosy had mycobacterial antigens and 17 out of 19 BT leprosy patients were positive for antigens. In general, in the BT patients the presence of the antigen was related to the host tissue reaction; this relationship was found in only half of the patients with indeterminate leprosy studied. During ENL mycobacterial antigens were found both intra- and extra-cellularly in the inflammatory infiltrate, but the polymorphonuclear leukocyte infiltration was seen only around the extracellular perivascular antigen. In reversal reaction, the inflammatory response was towards extracellular mycobacterial antigens. After this reaction there were no antigens demonstrable.

Animals↗

IgA and IgM antibodies against Mycobacterium leprae in cord sera and in patients with leprosy: an indicator of intrauterine infection in leprosy.

A solid-phase radioimmunoassay was developed for demonstration and quantification of IgA and IgM anti-M. leprae antibodies. IgA and IgM anti-M. leprae antibodies were demonstrated in a lepromatous serum pool, in various amounts in individual patients with lepromatous leprosy, and in lower concentration in tuberculoid leprosy and non-leprosy controls. IgA and IgM anti-M. leprae antibodies were demonstrated in cord sera from babies of mothers with leprosy. The reliability of fetal IgA and IgM antibody synthesis as an indicator of intrauterine infection in leprosy is discussed.

Antibodies, Bacterial↗

Antigens of PPD, old tuberculin, and autoclaved Mycobacterium bovis BCG studied by crossed immunoelectrophoresis.

The effect of heat on mycobacterial antigens was studied by crossed immunoelectrophoresis in a system permitting identification and analysis of about 30 distinct components in Mycobacterium bovis BCG. By heating BCG concentrated culture fluid and BCG sonicates to 120 degrees C for 15 min, most antigens detectable by reaction with rabbit anti-BCG antibodies were destroyed. The BCG antigens 60, 63, 82, and 89 still gave strong precipitate lines, antigens 1B and 23 gave weak but distinct precipitate lines, whereas BCG antigens 27, 71, and 84 did not precipitate but retained some of their ability to combine with anti-BCG antibodies. Tuberculin PPD preparations showed a varying antigen content, the most prominent component corresponding to BCG antigen 60, and 6 additional components being detected in PPD RT33. The polysaccharide antigen responsible for the prominent peak of BCG antigen 89 was not detected in PPD RT 23 or PPD RT33. Only 5 distinct antigenic components were detected in Old tuberculin. They corresponded to the components remaining in autoclaved BCG, with 60 and 89 being the only prominent peaks in direct precipitation tests. The relevance of these findings concerning purification of mycobacterial antigens and the importance of individual antigenic components for induction of delayed hypersensitivity is discussed.

Antibodies, Bacterial↗

Demonstration of antibodies reacting with different determinants on Mycobacterium leprae antigen 7.

A purified preparation of M. leprae antigen 7 was used to investigate the specificity of anti-M. Leprae 7 antibodies in leprosy sera in a radioimmunoassay. A solution containing arabinogalactan (AG) and arabinomannan (AM) inhibited the antibodies in some sera to a great extent, whereas the antibody activity was virtually unchanged in other sera under the same conditions. These findings indicate that the antibodies are directed against different determinants on M. leprae antigen 7. Antibodies against determinants other than AG and AM occurred particularly in lepromatous leprosy sera. In 12 out of 14 sera, AG and AM had similar inhibiting capacity. In one serum, AG had markedly higher inhibiting capacity than AM; in the last serum, the reverse was the case, demonstrating variation in anti-polysaccharide specificity in individual sera.

Antibody Formation↗

The antigens of Mycobacterium bovis, strain BCG, studied by crossed immunoelectrophoresis: a reference system.

A reference system for the soluble antigens of Mycobacterium bovis, strain BCG is described. The system is based on crossed immunoelectrophoresis with intermediate gel. A commercially available immunoglobulin preparation made from rabbit anti-BCG hyperimmune serum was used as reference antibodies, while a concentrated BCG culture filtrate was used as reference antigen. The pattern obtained was highly reproducible, and most of the components were stable when the fiftyfold-concentrated culture filtrate was stored at -20 degrees C. About thirty different antigenic components were selected as reference antigens and numbered. The majority of the reference antigens were present in extracts prepared from BCG by ultrasonication or bacterial press extraction. Use of the system for studies of antigenic relationship between mycobacteria, identification and quantification of antigens, and characterization of antimycobacterial antibodies are illustrated by examples. The antigens of two preparations of tuberculin purified protein derivative (PPD) were identified. The antigen designated BCG60 was found to be a najor constituent of tuberculin PPD. Evidence is presented that this antigen is cell wall associated.

Absorption↗

Structural studies of three IgG kappa proteins from a patient with multiple myeloma.

Three distinct IgG proteins of similar concentration and the same light-chain type were demonstrated in a myeloma serum. The bonds between the heavy and light chains were split, and the isolated gamma- and kappa-chains were characterized by crossed immunoelectrophoresis, subgroup determination and N-terminal amino acid sequence. The studies showed that the IgG heterogeneity was due to differences in the primary structure of the variable parts of the kappa-chains. Two of the kappa-chains belonged to subgroup V kappa I, and one chain, the most anodic one, belonged to V kappa III The gamma-chains were homogeneous and belonged to subgroup VHIII.

Aged↗

In vitro synthesis of anti-mycobacterial antibodies in biopsies from skin lesions of leprosy patients.

To demonstrate local synthesis of anti-Mycobacterium leprae antibodies, biopsies from skin lesions of leprosy patients were cultured in vitro in a medium containing 14C-labeled lysine and isoleucine, and the culture fluids were analyzed by crossed immunoelectrophoresis with intermediate gel and autoradiography. The results show that anti-M. leprae antibodies were synthesized in vitro in the biopsies from the skin lesions of leprosy patients and that the specificity of the locally produced antibodies varied from patient to patient.

Antibodies, Bacterial↗

Comparative studies of antigen 21 in Mycobacterium and Nocardia species: possible taxonomic relationships with Mycobacterium leprae.

Studies of Mycobacterium leprae, Mycobacterium tuberculosis and Nocardia caviae in comparison with each other and with other Mycobacterium and Nocardia species were performed on the basis of antigen 21 intramolecular heterogeneity. Three different antisera were used: rabbit anti-Mycobacterium smegmatis antiserum, rabbit anti-Nocardia asteroides antiserum, and a lepromatous serum pool. With reference to each of the three antiserum sources used the strains were ranked in an order of relatedness or sharing of determinants. The three antisera showed distinctly different antigen 21 antibody specificities reflecting the species origin of the immunogen. The present investigations confirmed that antigen 21 of N. caviae shares determinants with antigens from Mycobacterium strains which were not present in corresponding antigens of all other Nocardia strains tested. M. tuberculosis, as judged by antigen 21 analysis, occupies a position separate from both the slow-growing and the fast-growing mycobacterial clusters in accordance with accepted taxonomic relationships. An interesting possibility of establishing a position for M. leprae in relation to other mycobacterial species was apparent. The order of relatedness among the strains studied went from M. leprae to M. tuberculosis to N. caviae to Mycobacterium avium to Mycobacterium fortuitum, the last two being representatives of the slow-growing and fast-growing mycobacteria. It can therefore be concluded that evidence from antigen 21 analysis indicates that M. leprae is more closely related to M. tuberculosis than to the other strains investigated.

Antigens, Bacterial↗