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Biomedical subjects

M Hirn

Publications and source records attributed to M Hirn.

At least 37 records · Page 2Linked to original sources
PubMed1993

Expression of CD5 and CD72 on T and B cell subsets in rheumatoid arthritis and Sjögren's syndrome.

A minority of B cells express the CD5 marker, which is found on virtually all T cells, and CD72 has been defined as the CD5 ligand on the B cell membrane. The mean fluorescence intensity (MFI) of the CD5 molecules was shown to be higher on CD4+CD29+ than CD4+CD45RA+ in peripheral blood (PB) and synovial fluid (SF) of rheumatoid arthritis (RA) patients (P < 0.0001 and < 0.001), and PB of Sjögren's syndrome (SS) patients and normal controls (P < 0.02 and < 0.03). This MFI declined once the CD4 expressed HLA-DR in PB of SS patients (P < 0.004) and normal controls (P < 0.02) or CD25 in PB of RA (P < 0.004) and SS patients (P < 0.0004). There was a correlation between the CD5 MFI on CD4+CD45RA+ and CD4+CD29+ in RA (P < 0.001) as well as SS (P < 0.0007) PB. The CD72 MFI was impressively higher on CD5+ than CD5- B cells in PB and SF of RA patients (P < 0.0001 and P < 0.005) and PB of SS patients (P < 0.005) and normal controls (P < 0.005). Our data suggest that, in association with CD4CD29, CD5 is involved in CD5+B/CD5+ B cell interactions in non-organ-specific autoimmune diseases.

Adult↗
PubMed1993

Effect of hyperbaric oxygen and surgery on experimental multimicrobial gas gangrene.

An experimental multimicrobial gas gangrene rat model was developed and the therapeutic effect of surgery was compared to the combined effect of surgery and hyperbaric oxygen (HBO). The infection was caused by an intramuscular injection of a mixture of bacteria including Clostridium perfringens, Bacteroides fragilis, Escherichia coli and Streptococcus faecalis. The mortality, morbidity and wound healing were assessed during a follow-up of 2 weeks. The mortality of the control rats was 60%, with rats treated with surgery alone 35% and the combined treatment group 20% (NS). In the combined treatment group, 84.4% of the survivors healed completely; the corresponding figure in the surgery group was 15.4% (p < 0.001). In experimental multimicrobial gas gangrene the addition of HBO to surgery reduces morbidity and improves wound healing but does not reduce mortality statistically significantly.

Animals↗
PubMed1993

Hyperbaric oxygen in the treatment of gas gangrene and perineal necrotizing fasciitis. A clinical and experimental study.

Between 1971 and 1987, 32 patients with clostridial gas gangrene were treated in the Department of Surgery, University of Turku. A presumptive diagnosis of gas gangrene was made on the basis of the clinical appearance of the patient and a predominance of Gram positive rods on stain. Between 1973 and 1989, 11 patients with perineal necrotizing fasciitis (Fournier's gangrene) were treated. The diagnosis was based on fulminating progression of perineal gangrene and on the presence of multiple pathogenic organisms in the primary Gram stain or culture. All patients in both series underwent surgical debridement, antibiotic therapy, and intensive care. In addition, the patients were exposed to pure oxygen at 2.5 atmospheres absolute pressure (ATA) for 120 minutes. Three such treatments were given during the first 24 hours after admission after which the treatment was repeated twice daily. Seventeen patients with clostridial gas gangrene had diffusely spreading myonecrosis; 6 died. Fifteen patients developed clostridial cellulitis with toxicity; 3 died. Thus, the overall mortality in gas gangrene was 28%. All the 9 patients who died had been transferred from other hospitals in Finland and were moribund on arrival. The infection in 8 of these patients developed postoperatively. None of the patients with a posttraumatic infection died. Each of the patients with Fournier's gangrene had had nonspecific symptoms before the gangrene became evident. The infection originated from the anorectal area in 5 patients, 1 patient had sustained a scrotal trauma and in 5 patients the underlying condition was unknown. One patient died 2 days after admission. Six patients required a colostomy. To evaluate the therapeutic value of hyperbaric oxygen (HBO) treatment, two experimental models of clostridial gas gangrene, mono- and multimicrobial, were developed in rats. In the monomicrobial infection model, 10(7) colony forming units (cfu) of Clostridium perfringens were injected intramuscularly into the left hind limb of the rat. The mortality of untreated rats was 100%. The mortality of the rats treated with surgery alone was 38% compared to 13% when surgery was used in combination with HBO (p < 0.01; chi 2 test). In the group treated with HBO and surgery, 94% of the survivors healed completely and were able to walk normally, whereas the corresponding figure in the rats treated with surgery alone was 20% (p < 0.001; chi 2-test). In the multimicrobial gas gangrene model the infection was induced by an intramuscular injection of a mixture containing approximately 10(7) cfu of each of the following bacteria: Clostridium perfringens, Bacteroides fragilis, Escherichia coli and Streptococcus faecalis.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1993

[Post infection antiidiotype vaccination against HIV: results of a phase Ia pilot study].

The mAb IOT4A against the HIV-gp 120 binding site on CD4 was shown to elicit the production of specific anti-idiotypes in rabbits neutralising HIV-1 in vitro. This study was designed in order to determine the safety and efficacy of the mAb IOT4A for the immunization of HIV+ volunteers. 10 patients in stages WR2-WR4B of HIV-disease were given six s.c. injections of the mAb IOT4A as an alum precipitate (each 3 patients receiving 0.6 or 1.2 mg, 4 patients receiving 2.4 mg). 6 patients subsequently received a booster immunization with the same dose of the mAb IOT4A. The immunization schedule was accompanied by monitoring clinical, immunologic and virologic parameters. No systemic toxic or allergic effects of the idiotype vaccine were observed. 8/10 vaccinees displayed a delayed-type hypersensitivity at the location of antibody administration beyond the third injection. The relative and absolute CD4 count showed a sustained increase in 8/10 patients at the end of the booster immunization and an additional raise after booster immunization in 6/6 patients. 624 antigen levels became negative in 2/2 patients during vaccination. In 4/10 patients in increase in HIV/gp 120 antigen binding titres was observed. HIV neutralisation titer remained stable throughout the observation period, and no progression in HIV disease was observed in all patients included in this study. The administration of the mAb IOT4A as a vaccine in HIV-infected volunteers was well tolerated. The mAb ITO4A induced the production of specific anti-idiotypes, that might have been of clinical benefit.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Anti-Idiotypic↗
PubMed1992

Treatment of central nervous system B lymphoproliferative syndrome by local infusion of a B cell-specific monoclonal antibody.

A 9-month-old infant developed Epstein-Barr virus-induced lymphoproliferative syndrome with mediastinal and central nervous system localizations, associated with mediastinal tuberculosis, 5 months after heart transplantation. As a combination of anti-B cell antibodies (CD21- and CD24-specific) and recombinant interferon alpha 2b, given intravenously, was not effective on the central nervous system disease, the anti-CD21 antibody was infused intrathecally via an Ommaya reservoir. High local concentrations of monoclonal antibodies were achieved, with no adverse effects. A dramatic clinical response was obtained, with clearance of abnormal cells from the cerebrospinal fluid and a clear reduction in the abnormalities on the brain images. The patient is well 7 months later. This observation indicates that treatment of B lymphoproliferative syndrome with central nervous system localization is feasible using a nontoxic, local B cell-specific approach.

Antibodies, Monoclonal↗
PubMed1992

Effect of hyperbaric oxygen and surgery on experimental gas gangrene.

An experimental model of clostridial gas gangrene was developed in rats and the therapeutic value of surgical debridement alone versus a combination of surgery and hyperbaric oxygen (HBO) was assessed. The infection was produced by an intramuscular injection of Clostridium perfringens microorganisms. The mortality of untreated rats was 100%. The mortality of the rats treated only with surgery was 37.5% compared to 12.5% when HBO was added to the treatment protocol (p < 0.01). In the group treated with HBO and surgery 82.5% of the animals healed completely and were able to walk normally, whereas the corresponding figure in the rats treated with surgery alone was 12.5% (p < 0.001). In the present experimental setting HBO treatment was an important therapeutic adjunct to surgery reducing both mortality and morbidity.

Animals↗
PubMed1991

Anti-LFA1 monoclonal antibody (25.3) for treatment of steroid-resistant grade III-IV acute graft-versus-host disease.

The in vivo efficacy of 25.3 monoclonal antibody (mAb) directed against human LFA1 molecule was assessed in ten patients with steroid-resistant grade III-IV acute graft-versus-host disease (AGVHD). These patients received non-T-cell-depleted allogeneic bone marrow transplantation for aplastic anemia in two cases and hematologic malignancies in eight cases. Five grafts were fully matched, three were one antigen-mismatched, and two were two antigen-mismatched. Despite GVHD prophylaxis with cyclosporin A and short-term methotrexate, AGVHD occurred after a median of 24 days and clearly progressed under prednisone (median 2 mg/kg), given for a median of 12 days. 25.3 mAb was given at a dosage of 0.1 mg/kg in a 4-h perfusion for five daily doses without any clinical or biological side effects. Thirty percent of the patients experienced a reduction in the overall grading with two complete responses. Partial response in at least one involved organ (mostly skin) occurred in 80% of the patients. However, seven out of the eight responding patients experienced a new episode of AGVHD. This observation, which confirms that inhibiting a functional molecule is as efficient as a cytolytic therapy, offers an alternative strategy to antithymocyte globulin (ATG) and cytotoxic mAb in controlling steroid-resistant GVHD.

Acute Disease↗
PubMed1991

Effect of anti-LFA1 (CD11a) monoclonal antibodies in acute rejection in human kidney transplantation.

A murine IgG1 monoclonal antibody, 25-3 (Immunotech, France), directed against the alpha chain (CD11a) of the human LFA1 molecule was used in the treatment of 7 histologically documented first acute rejection in first kidney transplantations under cyclosporine. Four patients (group I) received 20 mg/day for 2 days and 10 mg/day for 8 days of 25-3 MoAb. One developed Quincke's edema after the first injection of 25-3 and was immediately withdrawn from the study. In 2 patients, whose serum creatinine continued to increase, 25-3 MoAb was replaced by steroids, followed by ALG after 3 and 4 days of treatment, respectively. In the last case, rejection was reversed by 25-3 MoAb alone. As the clinical response of rejection to 25-3 was poor, another group of 3 patients (group II) was treated with 25-3 at a dose of 40 mg/day for 2 days, 20 mg/day for 2 days, and 10 mg/day for 6 days, but 25-3 was still unsuccessful in reversing acute rejection, and rescue treatment was initiated between days 5 and 8 in all cases. MoAb tolerance was excellent in 3 patients. With the exception of the one case of Quincke's edema, only minor side effects were noted in the last 3 recipients. 25-3 MoAb serum trough levels peaked between 1.5-3.5 micrograms/ml at day 3 in group I and between 2-9 micrograms/L at day 2 in group II. Surprisingly, only one patient, in group I, exhibited a borderline IgG immune response against 25-3. These findings suggest that the 25-3 anti-CD11a MoAb is ineffective in controlling the course of acute rejection in kidney transplantation. However as already reported for another anti-LFA1 or with an anti-CD4 MoAb in mouse, 25-3 would be the first example in humans of a MoAb that does not elicit a strong immune response against its own determinants. This property might have important applications if 25-3 can prevent rejection in a prophylactic protocol or block the immune response against other MoAbs.

Adult↗
PubMed1991

The soluble receptor of interleukin 2 is not a serum marker of the autoimmune activity in type I diabetes mellitus.

In order to determine if soluble interleukin 2 receptor (IL2R) was useful as a marker in screening for early Type 1 diabetes and in monitoring immunological treatment, we assayed serum IL2R levels in 67 controls, 43 patients with newly diagnosed diabetes and 28 first degree relatives of diabetic patients (5 subjects were islet cell antibody positive). In 23 diabetes, specimens were analysed at 3 and 6 months after diagnosis whether or not cyclosporin A was administered. Seven patients were in a clinical trial using anti IL2R monoclonal antibody and cyclosporin A. Since IL2R level in the normal population is elevated in the first 5 years of life then decreases until adulthood (age:IL2R correlation between 0 and 15 years: r = -0.42, P less than 0.05), subjects were carefully matched in age. In recent onset diabetes, this negative correlation disappeared and IL2R levels tended to decrease particularly in younger subjects. In Type 1 prediabetic subjects presenting persistent islet-cell antibody serum IL2R was not elevated. During immunological treatment of recent onset diabetes, serum IL2R remained stable and was not modified by cyclosporin A. As expected IL2R became undetectable during treatment with anti IL2R MC Ab. But it rebounded when treatment was stopped with no effect on remission. We concluded that IL2R levels in Type 1 diabetic patients is not useful in screening autoimmune activity or in evaluating the effectiveness of immunosuppressors.

Adolescent↗
PubMed1991

Prevention of acute GVHD by in vivo use of anti-interleukin-2 receptor monoclonal antibody (33B3.1): a feasibility trial in 15 patients.

Results of allogeneic bone marrow transplantation (BMT) are still impaired due mainly to acute graft-versus-host disease (GVHD). Successful T cell depletion may abolish GVHD but causes increased rates of rejection and relapse. In vivo blocking of the CD25 receptor on T cells induces efficient and selective immunosuppression. We present results of a pilot trial studying the use of a CD25 MoAb (33B3.1) to prevent acute GVHD after allogeneic BMT. Fifteen patients were included in the study; 14 had a fully HLA matched sibling donor. In association with short methotrexate and cyclosporin A post-graft immunosuppression, the patients received 10 mg of 33B3.1 monoclonal antibody daily according to three successive schedules to study toxicity on marrow graft. No major adverse clinical experiences occurred. Engraftment was not delayed; after 4 months, full chimerism was documented in 14/15 studied patients. No human anti-rat antibody was detected during treatment period. No GVHD occurred during the period of antibody administration. Two patients relapsed; seven are alive and well with a median follow-up of 650 days. This study justifies a prospective controlled study to determine the real impact of 33B3.1 on GVHD prophylaxis.

Acute Disease↗
PubMed1990

Randomized controlled trial of a monoclonal antibody against the interleukin-2 receptor (33B3.1) as compared with rabbit antithymocyte globulin for prophylaxis against rejection of renal allografts.

Interleukin-2 is a major growth factor for activated T lymphocytes, and antibodies reacting with the Tac-chain component of the interleukin-2 receptor can prevent allograft rejection in animals. Because Tac chains are expressed only on a small fraction of activated lymphocytes, monoclonal antibodies against the interleukin-2 receptor may offer a more specific means of immunosuppression than polyclonal antilymphocyte globulin in prophylaxis against graft rejection. Therefore, we compared the immunosuppressive effect of 33B3.1, a rat monoclonal antibody against the human Tac chain, with the effect of a rabbit polyclonal antithymocyte globulin in a randomized study of 100 recipients of first renal transplants. Injections of 33B3.1 (10 mg per day) were tolerated well, whereas major side effects in 15 of 47 patients (32 percent) receiving antithymocyte globulin required discontinuation of treatment before day 14. The incidence of rejection episodes was not statistically different in the two groups at days 14, 30, 60, and 90 after transplantation. Patient and graft survival was also equal in the two groups at one year (96 and 85 percent, respectively, in both groups), and graft function was similar. The total number of infectious episodes within the first three months was lower in the 33B3.1 group than in the antithymocyte group (47 vs. 72). The drop in peripheral-blood lymphocyte concentrations was significantly larger in the patients treated with antithymocyte globulin. The level of circulating Tac-chain-bearing lymphocytes remained below 1 percent during 33B3.1 treatment, as compared with 4 to 5 percent during antithymocyte-globulin treatment (P not significant). We conclude that 33B3.1 is as effective as antithymocyte globulin in the prevention of renal-transplant rejection, and its use results in fewer infections and side effects.

Adolescent↗
PubMed1990

Functional studies of soluble low-affinity interleukin-2 receptors in rheumatoid synovial fluid.

Since abnormal regulation of interleukin-2 (IL-2) has been demonstrated in rheumatoid arthritis (RA), the functional role of low-affinity soluble IL-2 receptors (sIL-2R) purified from RA synovial fluids (SF) was studied. Picomolar levels of sIL-2R were detected in RA SF using an enzyme-linked immunosorbent assay. Levels were higher in serum and SF from RA patients than in controls (P less than 0.001) and higher in RA SF than in paired RA serum (P less than 0.01). Soluble IL-2R from RA SF had estimated molecular weights of 40-50 kd and 80-100 kd by gel filtration analysis. The 80-100-kd peak is likely to be a dimer of the 40-50-kd peak, since a single 45-kd peak was found after elution from sodium dodecyl sulfate-polyacrylamide gels. Since inhibitory activity for lymphocyte proliferation was found in the 80-100-kd range, the sIL-2R were purified with an anti-CD25 affinity column and further analyzed. The purified fractions did not interfere with the proliferation of mitogen-stimulated lymphocytes or with the binding of radiolabeled IL-2 to CTLL-2 cells, although direct binding of IL-2 was demonstrated. The affinity of sIL-2R from RA SF for binding IL-2 was in the range of 25 nM, which is similar to the affinity of sIL-2R purified from a human T cell clone, indicating that both sIL-2R are low-affinity receptors for IL-2. We conclude that the concentration and binding affinity of low-affinity sIL-2R purified from RA SF render them unable to interfere with IL-2-related activities.

Arthritis, Rheumatoid↗
PubMed1990

Interleukin 2 (IL 2) inhibitor in rheumatoid synovial fluid: correlation with prognosis and soluble IL 2 receptor levels.

A soluble activity inhibiting over 50% of the CTLL-2 cell line response to recombinant human interleukin 2 (IL 2) was found in 17 of 29 (59%) rheumatoid synovial fluids. To study the prognosis value of this activity, 16 rheumatoid synovial fluids were collected before a radiation synovectomy of the knee with 7 mCi of 90Yt. Patients with a good clinical result after the synovectomy had a lower IL 2 inhibitory activity than those with a bad or incomplete result (P less than 0.01). Levels of inhibitory activity and of soluble IL 2 receptors were correlated with each other and with the response of the synovitis to the radiation synovectomy. These results extend the clinical usefulness of soluble IL 2 receptor measurements and indicate a correlation between the immune activation of the rheumatoid synovitis and its clinical activity.

Adult↗
PubMed1990

Choroidal ependymocytes in culture: expression of markers of polarity and function.

Long-term primary cultures derived from fetal mouse or rat choroid plexus were obtained in serum-supplemented media. Monoclonal and polyclonal antibodies to basolateral and apical membrane components were used to observe the expression of specific markers of polarity and function. Choroid plexus cultures and thin frozen sections of adult tissues were compared by immunocytochemistry. Two polyclonal antibodies directed against laminin and fibronectin were used on cultured choroid plexus and sectioned tissues, showing that fibronectin and laminin are located on the basolateral membrane domain in ependymocytes in vitro, as well as in vivo. Na(+)-K(+) ATPase was apically detected by light and electron microscopy with a monoclonal antibody (Mab H30) in both cultured cells and sectioned tissues. Double immunofluorescent staining with Mab H30 and affinity-purified polyclonal antibodies to the alpha subunit of G0 protein (G0 alpha) demonstrated the relatively similar distribution of the two antigens on the apical face of the choroidal tissue, both in vivo and in vitro. The distribution of these markers shows a typical differentiation with maintenance of polarized features in choroidal ependymocytes in culture, testifying that this cell culture system constitutes an interesting model for studying the functional characteristics of ependymal cells of the choroid plexus.

Animals↗
PubMed1989

Pilot phase I study using zidovudine in association with a 10-day course of anti-CD4 monoclonal antibody in seven AIDS patients.

Experimental evidence has demonstrated that monoclonal antibody (MAb) 13B8.2, a workshop-qualified anti-CD4 MAb, (1) inhibits in vitro syncytium formation as well as in vitro HIV infection of CD4+ T cells; (2) delivers negative signals to T cells, thus preventing T-cell activation and viral replication; (3) contributes to CD4+ T-cell clearance by its Fc portion, and (4) induces an immune response by the patient, contributing potentially to an anti-idiotypic response of interest for the control of the immune parameters of the disease. On this basis a phase I study combining zidovudine treatment and a 10-day course of anti-CD4 MAb was performed in seven AIDS patients (Centers for Disease Control group IV). The treatment was well tolerated. MAb dosage and schedule were adjusted on the basis of circulating CD4+ cells and MAb pharmacokinetics; immunological and virological parameters were also monitored. One patient presented a transient increment in CD4+ T cells associated with augmented T-cell function, the suppression of p24 in the serum and a negative RT assay. A second patient had a steady increment of CD4+ T cells after completion of the treatment, with a transient decrease of serum p24 5 days after completion of the anti-CD4 protocol.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Anti-interleukin 2 receptor monoclonal antibody in the treatment of ongoing acute rejection episodes of human kidney graft--a pilot study.

Monoclonal antibodies (MoAbs) against human interleukin 2 receptor (IL-2-R) have been shown to prevent early kidney rejection in animals and humans. We report here the effect of an anti-IL-2-R MoAb (33B3.1) inhibiting IL-2 binding high-affinity sites on activated lymphocytes in 10 declared acute rejection episodes of first cadaveric kidney grafts. Six patients were under cyclosporine treatment only at the time of diagnosis of the rejection. All rejection episodes but one were biopsy-proved cellular rejections. Treatment consisted of intravenous infusions of 33B3.1 at 20 mg/day x 2 days, followed by 10 mg/day for 8 additional days. In case of MoAb ineffectiveness at day 5, anti-IL-2-R MoAb was discontinued and a rescue treatment of corticosteroid boluses (CSb) was given. If not, in all cases corticosteroids (CS) were given (1 mg/kg) at the end of MoAb treatment (day 10) and tapered off thereafter. Two rejection episodes immediately responded to 33B3.1 treatment. During 33B3.1 treatment four other patients had only a stabilization of their blood creatinine concentration, which nevertheless returned to prerejection levels after day 10 when anti-IL-2-R was discontinued and CS administered at 1 mg/kg (no rescue treatment). The four remaining patients had an increase of their blood creatinin levels at day 5 despite 33B3.1 treatment, and their renal function only improved with CSb rescue treatment. One of these patients lost the graft despite rescue treatment, as well as a 9-day course of antithymocyte globulin. Trough levels of MoAb reached a plateau as early as day 2 (approximately 6 micrograms/ml). All patients developed antibodies (IgM and IgG) after day 14. In no instance could unresponsiveness be related to low circulating 33B3.1 trough levels or to early host anti-MoAb immune response (IgM or IgG). We conclude that 33B3.1, known to be effective in preventing early rejection, has only inconsistent and/or incomplete effects on the ongoing rejection process. Our data suggest that once IL-2-dependent clones are expanded in the rejected graft, interference with IL-2/IL-2-R signals does not block the effector mechanisms sustaining acute rejection.

Antibodies, Monoclonal↗