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Biomedical subjects

G Bjune

Publications and source records attributed to G Bjune.

87 records · Page 5Linked to original sources
PubMed1978

Mycobacterium leprae specific antibodies detected by radioimmunoassay.

A radioimmunoassay was developed for demonstration of antibodies against M. leprae specific antigenic determinants. The specificity of the assay was tested with hyperimmune rabbit antisera against other mycobacteria and shown to be very high. The titre of M. leprae specific antibodies in a lepromatous serum pool was 10(5). Sixty-one of sixty-two lepromatous sera, all of twelve borderline sera and twenty of forty-eight tuberculoid sera were positive in the assay, whereas all of thirty-eight control sera from tuberculin positive individuals from a leprosy non-endemic area were negative. Aplication as a diagnostic test for subclinical infection with M. leprae is discussed. The principle of the test appears promising for serological distinction between pulmonary infection with M. tuberculosis and other mycobacteria.

Antibodies, Bacterial↗
PubMed1978

In vitro modulation of lymphocyte responses to phytohaemagglutinin by plasma in mother and baby at the time of birth. Increased lymphocyte responses in babies of mothers with lepromatous leprosy.

Peripheral blood lymphocytes from nineteen healthy mothers, mothers with borderline tuberculoid leprosy and fourteen mothers with borderline or polar lepromatous leprosy, and their newborn babies, were stimulated in vitro with phytohaemagglutinin (PHA). The responses in medium supplemented by serum from a pool of healthy non-pregnant individuals were compared with responses in medium supplemented by plasma from the mothers or from their babies, to assay for the presence of non-specific effects on T-cell responses. It was found that plasma from the mothers at the time of labour profoundly suppressed their own lymphocyte responses to PHA. However, the lymphocyte responses of healthy mothers were not significantly suppressed when cultivated in the presence of plasma from the babies, indicating that the suppressive factor(s) of normal pregnancy did not pass the placental barrier. Plasma from mothers with leprosy had a greater inhibitory effect on their babies' lymphocytes than plasma from healthy mothers. This raises the possibility that plasma from leprosy patients contains suppressive factors other than those associated with pregnancy. Babies of lepromatous leprosy mothers, who might have been exposed to mycobacterial antigens in utero, had higher PHA responses than the other babies, possibly due to a compensatory reaction to early stresses in the immune system.

Female↗
PubMed1977

Antibodies against BCG antigen 60 in mycobacterial infection.

A sensitive specific radioimmunoassay was developed to measure antibodies against BCG antigen 60, a prominent antigenic component of BCG bacilli which cross-reacts with similar components in many mycobacterial species including Mycobacterium leprae and M tuberculosis. A lepromatous serum pool had anti-BCG-60 activity with a titre of 10(5) and the tuberculoid pool a titre of 10(4). Testing of individual sera showed striking variations within groups of patients with lepromatous and tuberculoid leprosy. In five of the 20 tuberculoid leprosy sera the anti-BCG-60 activity was above the median for the lepromatous group. The current view that antibody formation against mycobacterial antigens is very low in tuberculoid leprosy thus no longer appears to be tenable. Sera from eight patients with active pulmonary tuberculosis also showed a striking variation in anti-BCG-60 content, and the median value of this group was even higher than in those with lepromatous leprosy.

Antibody Formation↗
PubMed1977

Common antigen of Mycobacterium leprae, M. lepraemurium, M. avium, and M. fortuitum in comparative studies using two different types of antisera.

No. 21 mycobacterial antigens of Mycobacterium lepraemurium, M. avium, M. fortuitum, and M. leprae were compared in crossed immunoelectrophoresis using two different antibody sources, a serum pool from lepromatous leprosy patients (LSII) and a rabbit anti-M. smegmatis antiserum. M. lepraemurium, like M. avium, was found to contain the 21 A and 21 C determinants. M. fortuitum contained in addition a new type of determinant, 21 D.M. leprae antigen no. 21 carried the A as well as the B dertminants, the latter found so far only in the leprosy bacillus. The separate taxonomic position of M. leprae, suggested by earlier studies of the no. 21 antigen, is further supported by the present results, which also demonstrate the potential use of submolecular heterogeneity for such investigations.

Animals↗
PubMed1976

Plasma factors in delayed-type hypersensitivity. Augmentation of lymphocyte responses in borderline leprosy reactions.

The phytohaemagglutinin-induced responses of lymphocytes were found to be inhibited by plasma from patients with leprosy when compared with their responses in pooled serum from healthy donors. When patients developed reversal reactions, the initial inhibitory effect of their plasma was replaced by an augmentary effect on the responses to phytohaemagglutinin. The period of augmentation coincided with that of the reversal reaction in patients with borderline tuberculoid leprosy, but was delayed in patients with borderline lepromatous leprosy. The plasma from each leprosy patient was also observed to have the same effect on lymphocytes from unrelated individuals, showing that the inhibition and augmentation were due to factors in the plasma and not to a change in lymphocyte receptors. It is possible that the normal stable state of leprosy results from the presence of factors in plasma which act as a control mechanism, and that delayed hypersensitivity reactions may be caused by a breakdown of this control.

Adolescent↗
PubMed1976

Lymphocyte transformation test in leprosy; correlation of the response with inflammation of lesions.

Lymphocyte transformation tests (LTT) using 'whole washed" and 'sonicated" preparations of Mycobacterium leprae (M. leprae) as antigen were studied in eighty-one patients with borderline leprosy. The results were correlated with the histological and the clinical pictures. There was a good correlation with the histological spectrum, LTT responses generally being higher in the borderline tuberculoid leprosy patients and lower in the borderline lepromatous. However, considerable variation was noted in each group of the borderline leprosy spectrum, and it was found that this was due in part to the degree of inflammation in the skin. Thus those with 'inflamed" skin lesions had higher responses than those with 'silent" lesions, and even those with borderline lepromatous leprosy with inflamed lesions had higher responses than those with borderline tuberculoid leprosy whose lesions were silent. Those who had reversal reactions, where inflammation is very marked, had very high LTT responses which fell with treatment of the reaction with steroids. It thus appears that the LTT in leprosy is influenced by the occurrence of hypersensitivity reactions as well as by the patient's ability to resist bacillary multiplication.

Adolescent↗
PubMed1975

Antigenic heterogeneity in patients with reactions in borderline leprosy.

Fifteen patients with borderline leprosy who developed "reversal" reactions were studied from the inception of treatment. Thirteen showed an appreciable increase in lymphocyte transformation (LT) when preparations of Mycobacterium leprae were used as antigen. The LT responses to either "whole" or "sonicated" preparations of the bacillus in these 15 patients and in nine others also in reaction correlated with the clinical presentation. Those with skin disease predominating in the reaction showed an appreciable increase in LT when whole M leprae was used as antigen. Those with nerve disease predominating showed an increase with sonicated M leprae. In those with both skin and nerve disease there was an increase with both antigen preparations. The ratios of the LT test results (whole to sonicated M leprae) showed highly significant differences between the three groups.

Adolescent↗
PubMed1975

Amyloid-related serum component (protein ASC) IN LEPROSY PATIENTS.

The presence of amyloid-related serum component, protein ASC, in serum samples from 63 leprosy patients was investigated. Protein ASC was detected in 38% of the patients. A correlation to the disease spectrum of leprosy was apparent: polar lepromatous cases, 64% positive; borderline lepromatous, 50%; borderline tuberculoid, 36%; subpolar tuberculoid, 17%; and polar tuberculoid, negative. Antibody activity against the a antigen of Mycobacterium leprae was also determined, showing a similar correlation to the disease spectrum. Serum samples from 23 apparently healthy Ethiopians serving as controls showed a protein ASC incidence of 22%. This figure is significantly higher than the frequency found by others among healthy Norwegian blood donors. Immunoglobulin M levels among patients were elevated in the borderline lepromatous and poplar lepromatous groups. The three tuberculoid groups did not differ in this respect from the control group but were all elevated as compared to a normal Caucasian serum pool. Although raised immunoglobulin M levels seemed to parallel increased frequencies of protein ASC in the patient groups as well as in controls, this correlation might be only secondary to a primary derangement in T-cell function.

Adult↗
PubMedDate not supplied

Persistence of DNA from Mycobacterium tuberculosis in superficially normal lung tissue during latent infection.

BACKGROUND: A third of the world's population has latent infection with Mycobacterium tuberculosis, and in areas of low endemicity, most cases of active tuberculosis arise as a result of reactivation of latent bacilli. We sought to establish the cellular location of these latent organisms to facilitate their elimination. METHODS: We applied in-situ PCR to sections of macroscopically normal lung tissue from 13 individuals from Ethiopia and 34 from Mexico who had died from causes other than tuberculosis. Sections of lung tissue from six Norwegian individuals (ie, individuals from a non-endemic population) acted as negative controls, and six Ethiopian tuberculosis cases acted as positive controls. FINDINGS: Control necropsy samples from the Norwegian individuals were all negative by in-situ PCR and conventional PCR, whereas all samples from known Ethiopian tuberculosis cases were positive by both methods. However, in macroscopically normal lung tissue from Ethiopian and Mexican individuals without tuberculous lesions, the in-situ PCR revealed five of 13 and ten of 34 positive individuals, respectively. These results were confirmed by conventional PCR with extracted DNA. Positive cells included alveolar and interstitial macrophages, type II pneumocytes, endothelial cells, and fibroblasts. INTERPRETATION: M. tuberculosis can persist intracellularly in lung tissue without histological evidence of tuberculous lesions. M. tuberculosis DNA is situated not only in macrophages but also in other non-professional phagocytic cells. These findings contradict the dominant view that latent organisms exist in old classic tuberculous lesions, and have important implications for strategies aimed at the elimination of latent and persistent bacilli.

Adolescent↗
PubMedDate not supplied

Mycobacterial antigens in antibody responses of leprosy patients.

A reference system for M. smegmatis antigens in crossed immunoelectrophoresis was used to study antibody activities in serum samples of 91 leprosy patients. All polar and borderline lepromatous patients were positive. Mean numbers out of 14 M. smegmatis antigens involved were 4.3 and 3.5, respectively. Precipitins against antigen no. 1 were seen in all lepromatous cases. Antibodies against this antigen were detected in 50% of tuberculoid (polar, subpolar and borderline) cases. Antibody activity against M. avium and M. duvalii antigens was also detected using a staphylococcal radio-immuno-assay. Borderline and polar lepromatous cases showed elevated levels. Antigenic comparisons were made between four slow growing mycobacteria, fourteen fast growing mycobacteria and the leprosy bacillus using lepromatous serum pools as antibody reagents. Four of the antigens detected in M. leprae were also found in slow growing as well as fast growing species indicating a common occurrence among mycobacteria. Antigen no. 1 of M. duvalii, with an apparent molecular weight of 290,000, showed nonprotein characteristics. Further analysis of antigen no. 21, using lepromatous serum pools as antibody reagents, indicated the existence of at least two groups of antigenic determinants. In addition to determinants shared by all mycobacteria, there were antigenic structures apparently unique to M. leprae.

Antibody Formation↗
PubMedDate not supplied

Comparison of various preparations of Mycobacterium leprae and other mycobacteria by lymphocyte stimulation.

Peripheral blood lymphocytes were stimulated in vitro with different mycobacterial antigen preparations and responses were measured as incorporation of tritiated thymidine. Blood donors were 9 patients with lepromatous leprosy, 16 tuberculoid leprosy patients, and 6 healthy individuals with different degrees of exposure to leprosy. The results revealed a good correlation between the responses to M. leprae from human sources and bacilli from armadillos inoculated with human leprosy bacilli, although the latter were less potent stimulators. Responses to BCG and PPD did not correlate with lymphocyte responses to human M. leprae. Acid-fast bacilli grown on LA-3 medium inoculated with human leprosy bacilli stimulated responses which did not correlate with responses to human M. leprae when positive responses were compared, but showed a good correlation when inhibitory effects of the bacilli on thymidine incorporation were studied. The significance of the lymphocyte stimulation test for identification of microbes is discussed.

Adolescent↗