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Biomedical subjects

C Brautbar

Publications and source records attributed to C Brautbar.

At least 55 records · Page 3Linked to original sources
PubMed1998

Limbal cell autograft transplantation for severe ocular surface disorders.

BACKGROUND: Limbal cell transplantation may improve the visual outcome after chemical trauma and ocular surface diseases. METHODS: Nine eyes of nine consecutive patients (eight males and one female, age 9-60 years), underwent limbal autograft transplantation (LAUT). In five cases LAUT was done for severe chemical burns in the acute stage (group 1). In four patients with old chemical trauma LAUT was performed years after the trauma (group 2). Penetrating keratoplasty (PKP) was carried out within 6 months after LAUT in three patients of group 2. Preoperatively, the visual acuity in all the patients except one was counting fingers. Postoperatively, patients were treated with topical antibiotics, topical corticosteroids and oral steroids. Oral cyclosporin was used after penetrating keratoplasty. RESULTS: No complications were observed during the surgical procedure. Postoperatively, the epithelialization was complete between days 7 and 12. The inflammatory response subsided within 3 months and the stromal neovascularization decreased. Visual acuity improved in all the nine cases, ranging from 6/6 to 6/30. The decreased visual acuity was due to corneal haze, scars and vascularization. Following PKP, the three grafts remained clear with intact epithelium. No complications were observed during the follow-up period from 7 to 60 months. CONCLUSIONS: Limbal cell transplantation is an efficacious procedure for rehabilitation of visual acuity after severe chemical trauma.

Acids↗
PubMed1998

Clinical and immunological study of 7 patients with minocycline-induced autoimmune phenomena.

PURPOSE: Prolonged treatment with minocycline for acne vulgaris has been associated with the development of arthralgia, arthritis, and other autoimmune phenomena. We characterized the clinical, laboratory, and immunological profiles of seven patients with this syndrome. SUBJECTS AND METHODS: Clinically the patients were studied with special emphasis on prior minocycline treatment, presenting symptoms, physical findings, course, and outcome. Laboratory tests included fluorescent antinuclear and antineutrophil cytoplasmic (ANCA) antibodies, as well as antibodies to myeloperoxidase, bactericidal permeability increasing protein, elastase, cathepsin G, lactoferrin, cardiolipin, and histone. RESULTS: All 7 patients presented with polyarthritis or arthralgia, morning stiffness, and fever after 6 to 36 months of minocycline treatment. The skin was involved in five patients (three with livedo reticularis and two with subcutaneous nodules). Two patients had chronic active hepatitis. Increased titers of perinuclear ANCA (p-ANCA) were detected in all seven patients; five patients had fluorescent antinuclear antibodies, two had antihistone autoantibodies and one had anticardiolipin antibodies. Antigenic characterization of p-ANCA disclosed antibodies to bactericidal permeability increasing protein in one patient, to elastase in three patients, and to cathepsin G in five patients. Symptoms resolved in five patients upon discontinuation of minocycline; the other two patients were treated with corticosteroids and also achieved remissions. CONCLUSION: Minocycline-induced autoimmune syndrome is characterized by reversible polyarthralgia or arthritis, morning stiffness, fever, frequent skin involvement, occasional chronic active hepatitis, and increased titers of p-ANCA with various minor p-ANCA-related antigens.

Acne Vulgaris↗
PubMed1998

HLA class II immunogenetics of IDDM in Yemenite Jews.

The association between HLA-DR and DQ and insulin dependent diabetes mellitus (IDDM) was analyzed in 47 patients and 76 controls of Yemenite Jewish origin. The IDDM susceptibility alleles DRB1*03011, DQA1*0501, DQB1*02 and DRB1*0402, DQA1*0301, DQB1*0302 found in Caucasians had a very strong predisposing effect also in the Yemenite IDDM group. The DRB1*07, DQA1*0201 and DQB1*02 alleles were found to have a strong negative association with IDDM. None of the patients carried DRB1*07 and DQA1*0201 compared with healthy controls (43.7%). Our analysis revealed that the DRB1*03011 DQA1*0501 DQB1*02/DRB1*04 DQA1*03 DQB1*0302 heterozygous genotype confers the highest susceptibility (59.6% in patients vs. 0% in controls). The homozygous DRB1*03 and DRB1*04 genotypes were also found to be positively associated with the disease. 81% of the patients compared to 1.3% of controls carried the susceptibility alleles on both haplotypes. In conclusion, the development of IDDM in Yemenite Jews is strongly dependent on the presence of the susceptibility HLA alleles and on the absence of the DRB1*07 haplotype. The Yemenite Jewish group is uniquely homogenous with regard to genetic susceptibility factors involved in the process of IDDM, and may thus be an ideal model for further genetic studies.

Alleles↗
PubMed1998

Allogeneic cell-mediated and cytokine-activated immunotherapy for malignant lymphoma at the stage of minimal residual disease after autologous stem cell transplantation.

Immunocompetent donor-derived T lymphocytes play a crucial role in the elimination of residual leukemic cells post allogeneic bone marrow transplantation. Because this graft versus leukemia (GVL) effects is absent after autologous stem cell transplantation (ASCT), a high rate of relapse ensues. We introduced cell-mediated immunotherapy at the stage of minimal residual disease in lymphoma patients to help effect a GVL-like reaction by adoptive transfer of immunocompetent human leukocyte antigen-matched donor peripheral blood lymphocytes (PBL). Thirteen consecutive patients with high-risk lymphoma were treated with allogeneic cell therapy (AlloCT) after having undergone ASCT. In the absence of graft-versus-host disease, cell therapy-induced graft-versus-lymphoma reaction was amplified by human recombinant interleukin 2 (rIL-2) during 3 days to activate donor PBL in vivo, followed by infusion of in vitro rIL-2 activated donor lymphocytes combined with 3-day rIL-2 therapy. Nine of the patients underwent the treatment protocol well. In the four other patients, in whom the AlloCT resulted in marrow aplasia due to elimination of host hematopoietic cells, treatment with donor marrow cell infusion without further conditioning was performed. Adoptive cell therapy in the form of AlloCT may turn out to be an effective therapeutic modality for the treatment of resistant residual disease in lymphoma patients.

Adolescent↗
PubMed1998

Hereditary CD4+ T lymphocytopenia.

Two siblings suffering from mental retardation, progressive bronchiectasis, extensive warts, and persistent hepatitis B are described. The propositus also had an unusual physiognomy and non-specific colitis. Both patients had a marked decrease in the population of CD4+ helper T cells.

Adolescent↗
PubMed1998

Analysis of allelic association between D6S461 marker and multiple sclerosis in Ashkenazi and Iraqi Jewish patients.

A genetic factor contributing to multiple sclerosis (MS) disease risk is evident by the increased prevalence of disease among siblings of probands. A recent genome screen on Canadian sib pairs suffering from MS identified linkage between the genetic marker D6S461 and MS, and showed disequilibrium in transmission of its 260-bp allele from heterozygous parents to affected siblings (Ebers et al., 1996). The present study examined the allelic segregation of this marker among MS patients of Iraqi Jewish and Ashkenazi origin, two homogeneous ethnic groups that differ considerably from Caucasians. The frequency of the 260-bp allele reached 28.3% among Iraqi MS patients (n = 30) and 25.2% among the Ashkenazi patients (n = 121) compared with 19.6% (n = 28) and 21.3% (n = 115) in respective origin-matched controls (for the combined data set, p = 0.18). A secondary analysis of the frequency of the 260-bp allele in clinical subgroups showed a frequency of 38.1% among patients with juvenile MS (i.e., onset by 21 yr of age) of Ashkenazi origin (n = 21, p = 0.019) and 38.8% in the combined pool (n = 27, p = 0.0045). Most (90%) of the juvenile MS patients belonged to the relapsing-remitting subgroup, which itself showed a frequency of 28.5% of the 260-bp allele (n = 121, p = 0.045). The results suggest that the D6S461 region may contain a locus contributing to an early onset of relapsing-remitting MS.

Adolescent↗
PubMed1998

Enhanced lymphoid cell recovery after bone marrow transplantation: correlation with the presence of costimulatory antibodies in serum.

We describe a patient with T cell deficiency who underwent bone marrow transplantation (BMT) from an HLA-identical brother. The patient's white blood cell count recovered with exceptional rapidity post-BMT: after 7 to 9 days it rose sharply to 98x10(9) cells/L, 76% of which were mononuclear leukocytes. It then decreased, and a second peak was observed 250 days post-BMT. Lymphocytes from both peaks displayed a phenotype of mature T cells together with characteristics of a constitutively activated state; that is, they 1) exhibited high levels of tyrosine-phosphorylated T cell receptor (TCR) zeta chain, 2) spontaneously secreted IL-2, 3) expressed activation specific cell surface markers, and 4) were unresponsive to in vitro stimuli. The increased cell counts in both peaks correlated with the presence of anti-lymphocytic antibodies in the patient's serum, which reacted with peripheral blood lymphocytes (PBLs) both from the donor and from unrelated individuals. These antibodies were present before BMT and reappeared post-BMT. Variable number tandem repeats analysis revealed that the patient's PBLs were chimeras for up to 2 years post-BMT. This finding could explain the newly synthesized post-BMT anti-lymphocytic antibodies and the appearance of the second WBC peak during that period. The patient's anti-lymphocytic antibodies displayed costimulatory activity, enhancing the in vitro proliferation of normal T cells suboptimally activated via the TCR. The unique characteristics of these antibodies could explain the enhanced T cell recovery observed post-BMT as well as the constitutive activation state of these cells. Furthermore, such antibodies may eventually facilitate development of a therapeutic method for inducing enhanced post-BMT recovery.

Adolescent↗
PubMed1998

Dysregulation of inflammatory cytokines in unrelated bone marrow transplantation.

The dysregulation of cytokines is thought to play a role in the inflammatory and allospecific components of graft-versus-host disease (GVHD) and graft rejection (GR) post allogeneic bone marrow transplantation (BMT). Both complications occur post unrelated BMT at significantly higher frequencies than post BMT from identical sibling donors. The levels of tumor necrosis factor alpha (TNF-alpha) and interleukin (IL)-1beta, IL-6, IL-10 and IL-12 following unrelated BMT were measured to examine cytokine dysregulation involvement in GVHD and GR. Of the 26 patients included in this study, 15 developed GVHD (14 acute; 1 acute and chronic), 5 had GR and 6 had uneventful BMT. TNF-alpha was markedly elevated in 13/15 of the patients with GVHD and in 3/5 patients with GR. IL-6 was elevated in patients with acute GVHD and with GR. IL-12 levels were similar in pre- and post-BMT sera. No correlation was found between HLA-C match and cytokine levels. In conclusion, a positive correlation was found between elevated levels of TNF-alpha, IL-6 and IL-10, and GVHD (p < 0.05, p < 0.005 and p < 0.002 respectively) and GR (p < 0.01).

Adolescent↗
PubMed1997

HLA and graft-versus-host disease: a population-based study of HLA phenotypes of Jewish and Arabic bone marrow transplanted patients in Israel.

The relationship between the incidence of graft-versus-host disease (GVHD) and human leukocyte antigens (HLA) was analyzed in HLA-identical sibling bone marrow transplantation donor/recipient pairs from the two major populations in Israel: Jewish and Arabic. HLA phenotypes were significantly different, in both groups, between patients and healthy controls. Among Jews, a higher incidence of GVHD was found with A28, CW3, CW6 of class I and DR7, DQ2 of class II; a lower incidence was found with A2, A26, B14. Among Arabs, a higher incidence of GVHD was found with B41, CW7 of class I, and DR2, DR13 of class II. The development of GVHD is apparently associated with HLA phenotypes specific to each population.

Adolescent↗
PubMed1997

Reactivity of T cells from seronegative patients with myasthenia gravis to T cell epitopes of the human acetylcholine receptor.

Seronegative (SN) patients with myasthenia gravis (MG) have clinical and electrophysiologic features similar to those of seropositive (SP) patients, and they respond to the same therapeutic measures. However, because SN patients lack detectable (by standard radioimmunoassays) serum antibodies to acetylcholine receptor (AChR), which are considered to have a crucial role in MG, the pathophysiologic basis for the disease is not clear. We therefore compared the ability of peripheral blood lymphocytes (PBL) of SN patients (11) and SP patients (39) to respond to myasthenogenic T cell epitopes of human AChR. We tested two aspects that relate to T-cell immunity: 1) T cell responses to myasthenogenic peptides by proliferation and IL-2 production, and 2) the ability of antigen-presenting cells to bind these T-cell epitopes. T cells of SN patients did not differ from those of SP patients in their ability to respond and to bind the two human AChR-derived myasthenogenic peptides. This supports the belief that most SN patients indeed suffer from an autoimmune disease directed against the AChR. The presence of T-cell immunity in the absence of antibodies may emphasize the importance of AChR-specific T cells in MG.

Adult↗
PubMed1996

Peptide analogs to pathogenic epitopes of the human acetylcholine receptor alpha subunit as potential modulators of myasthenia gravis.

Myasthenia gravis is an autoimmune disease in which T cells specific to epitopes of the autoantigen, the human acetylcholine receptor, play a role. We identified two peptides, p195-212 and p259-271, from the alpha subunit of the receptor, which bound to major histocompatibility complex (MHC) class II molecules on antigen-presenting cells (APCs) from peripheral blood lymphocytes of myasthenia gravis patients and stimulated lymphocytes of >80% of the patients. We have prepared analogs of these myasthenogenic peptides and tested their ability to bind to MHC class II determinants and to interfere specifically with T-cell stimulation. We first determined relative binding efficiency of the myasthenogenic peptides and their analogs to APCs of patients. We found that single substituted analogs of p195-212 (Ala-207) and p259-271 (Lys-262) could bind to human MHC molecules on APCs as efficiently as the original peptides. Moreover, dual analogs containing the two single substituted analogs in one stretch (either sequentially, Ala-207/Lys-262, or reciprocally, Lys-262/Ala-207) could also bind to APCs of patients, including those that failed to bind one of the single substituted analogs. The single substituted analogs significantly inhibited T-cell stimulation induced by their respective myasthenogenic peptides in >95% of the patients. The dual analogs were capable of inhibiting stimulation induced by either of the peptides: They inhibited the response to p195-212 and p259-271 in >95% and >90% of the patients, respectively. Thus, the dual analogs are good candidates for inhibition of T-cell responses of myasthenia gravis patients and might have therapeutic potential.

Adult↗
PubMed1996

Allogeneic cell therapy with donor peripheral blood cells and recombinant human interleukin-2 to treat leukemia relapse after allogeneic bone marrow transplantation.

Allogeneic bone marrow transplantation (BMT) is the only effective treatment for hematologic malignancies resistant to conventional chemotherapy. Until recently, no cure existed for patients who relapsed post-BMT. We present our long-term observations on remission induction, after relapse post-BMT, by allogeneic cell therapy (allo-CT) and the feasibility of remission induction in allo-CT-resistant patients by activation of antileukemia effector cells with recombinant human interleukin-2 (rhIL-2) in vitro and in vivo. The longest observation of successful allo-CT (event-free survival, greater than 8 years) was made in a patient with resistant pre-B lymphoblastic leukemia who received infusions with graded increments of donor (female) peripheral blood lymphocytes (PBL) as soon as bulky hematologic and extramedullary relapse was noticed early post-BMT. The patient is currently without evidence of residual host (male) cells as determined by polymerase chain reaction (PCR). Of 17 patients with acute and chronic leukemia in relapse after BMT, 10 were reinduced into complete remission. Four patients with cytogenetic relapse responded to allo-CT alone, while five of six patients with overt hematologic relapse responded only after additional activation of donor with rhIL-2. Allo-CT can, therefore, successfully reverse chemoradiotherapy-resistant relapse of both acute and chronic leukemia. Moreover, in patients resistant to donor lymphocyte infusion, remission can be accomplished by additionally activating donor PBL in vitro and/or in vivo with rhIL-2. Based on our observations, after BMT, allo-CT should be considered the treatment of choice for patients with hematologic malignancies resistant to conventional anticancer modalities. Allogeneic activated cell therapy (allo ACT) should be considered for patients with tumor cells resistant to allo-CT. Although allo-CT, followed if indicated by allo-ACT, can be effective for patients with overt hematologic relapse, reversal of persistent minimal residual disease or documented molecular/cytogenetic relapse early after BMT may also be considered as a possible indication for allo-CT.

Adolescent↗
PubMed1996

Effect of human recombinant erythropoietin therapy on panel reactive antibodies in chronic dialysis patients.

To examine whether recombinant human erythropoietin (rhEPO) therapy results in decreased presensitization to foreign HLA antigens, we retrospectively analyzed data from 64 of 200 patients treated in a university hospital dialysis center between 1985 and 1995 who had undergone routine panel reactive antibody (PRA%) screening. Though a significant decrease in the annual frequency of highly sensitized patients over the years was noted, 16 patients followed for 27.1 +/- 3.7 months after initiation of rhEPO therapy until transplantation or blood transfusion showed no significant overall decrease in PRA%. Six highly presensitized patients had moderate but significant overall decrease in PRA%. However, in three of these patients the PRA% was unchanged and in the other three patients the PRA% remained over 50%. Thus rhEPO therapy reduced the incidence of highly presensitized patients, but previously presensitized patients remained presensitized. We conclude that removal of transfusional stimulation of lymphocytotoxic antibody production does not appear to benefit previously presensitized patients, possibly due to the maintenance of B-lymphocyte clonal expansion by unknown factors, or even by rhEPO itself.

Antilymphocyte Serum↗