Major histocompatibility complex-restricted H-Y-specific antibodies and cytotoxic T lymphocytes may recognize different self determinants.

Previous studies have shown that influenza virus-immune cytotoxic T lymphocytes can recognize virus in conjunction with self HLA-A2 antigens. Nevertheless, the virus-infected target cells from one HLA-A2-positive male donor (designated M7) could not be lysed by the virus-immune cytotoxic lymphocytes from any HLA-A2-matched unrelated donors. Although extensive serological analyses showed no difference between the HLA-A2 antigens of donor M7 and other HLA-A2-positive donors, isoelectric focusing of the HLA-A2 molecule from donor M7 revealed a clear difference in the heavy polypeptide chains when compared with the HLA-A2 molecules of other donors. The present study demonstrates that the HLA-A2-restricted anti-H-Y cytotoxic T lymphocytes obtained from a female aplastic anaemia patient fail to lyse the male M7 target cells, whereas the HLA-A2-restricted anti-H-Y antibodies from the same patient react with the cells of donor M7. These results suggest that: (a) HLA-A2-restricted anti-H-Y antibodies can recognize self determinants on the HLA-A2 molecule that are distinct from those that are recognized by HLA-A2-restricted anti-H-Y cytotoxic T cells; and (b) HLA-restricted T and B cells may use different receptor repertoires for the recognition of foreign antigens such as H-Y.

Production, expansion, and clonal analysis of T cells with specific HLA-restricted male lysis.

A cytotoxic T cell (CT) lines grown as a population (CT line) was initiated from the peripheral blood lympocytes (PBL) of a female aplastic anemia patient who was known to express CT that were able to lyse HLA-A2-positive male cells. The anti-H-Y HLA-A2-restricted cytotoxic activity could be maintained over prolonged periods of time. The CT lines could be expanded and maintained in culture for >65 d by the use of mitogens and irradiated feeder cells. Out of 68 cultures obtained after cloning of the CT lines, 43 showed varying, but always specific, anti-H-Y HLA-A2-restricted lytic capacity on a per-cell basis. We could show that the cloned cultures were composed of >80% T cells that carry the HLA-A, -B, -C, and also the HLA-DR antigens identical to the original PBL.

Human H-Y: a male-specific histocompatibility antigen derived from the SMCY protein.

H-Y is a transplantation antigen that can lead to rejection of male organ and bone marrow grafts by female recipients, even if the donor and recipient match at the major histocompatibility locus of humans, the HLA (human leukocyte antigen) locus. However, the origin and function of H-Y antigens has eluded researchers for 40 years. One human H-Y antigen presented by HLA-B7 was identified as an 11-residue peptide derived from SMCY, an evolutionarily conserved protein encoded on the Y chromosome. The protein from the homologous gene on the X chromosome, SMCX, differs by two amino acid residues in the same region. The identification of H-Y may aid in transplantation prognosis, prenatal diagnosis, and fertilization strategies.

The minor histocompatibility antigen HA-1: a diallelic gene with a single amino acid polymorphism.

The minor histocompatibility antigen (mHag) HA-1 is the only known mHag for which mismatching is correlated with the development of severe graft versus host disease (GvHD) after human leukocyte antigen-identical bone marrow transplantation. HA-1 was found to be a nonapeptide derived from an allele of the KIAA0223 gene. The HA-1-negative allelic counterpart encoded by KIAA0223 had one amino acid difference from HA-1. Family analysis with HA-1 allele-specific polymerase chain reaction showed an exact correlation between this allelic polymorphism and the HA-1 phenotype. HA-1 allele typing of donor and recipient should improve donor selection and allow the determination of bone marrow transplantation recipients with high risk for HA-1-induced GvHD development.

Identification of a graft versus host disease-associated human minor histocompatibility antigen.

Minor histocompatibility antigen disparities between human leukocyte antigen (HLA)-matched bone marrow donors and recipients are a major risk factor for graft versus host disease (GVHD). An HLA-A2.1-restricted cytotoxic T cell clone that recognized the minor histocompatibility antigen HA-2 was previously isolated from a patient with severe GVHD after HLA-identical bone marrow transplantation. The HLA-A2.1-bound peptide representing HA-2 has now been identified. This peptide appears to originate from a member of the non-filament-forming class I myosin family. Because HA-2 has a phenotype frequency of 95 percent in the HLA-A2.1-positive population, it is a candidate for immunotherapeutic intervention in bone marrow transplantation.

Stroma-conditioned media improve expansion of human primitive hematopoietic stem cells and progenitor cells.

It has been reported that stroma-dependent cultures support proliferation of hematopoietic stem cells (HSC). In order to investigate the effect of soluble stromal factors, we developed short-term serum-low liquid cultures in which the effect of stroma-conditioned media (SCM) from the murine FBMD-1, and human L87/4 and L88/5 cell lines was studied on the maintenance and expansion of various human HSC subsets in CD34-positive selected mobilized peripheral blood stem cells (PBSC) from autologous transplants of lymphoma and multiple myeloma patients. The human cobblestone area forming cell (CAFC) assay was employed to determine the frequencies of both the CAFC weeks 2 to 4 as tentative indicators of progenitor and transiently repopulating HSC, and the more primitive CAFC weeks 6 to 8 as indicators of long-term repopulating HSC. In 7-day liquid cultures containing interleukin-3 (IL-3), stem cell factor (SCF) and IL-6, we recovered 3.0-fold more colony-forming cells (CFC) and 1.7- to 1.9-fold more CAFC weeks 2 and 4. The absolute number of primitive CAFC weeks 6 and 8 were only maintained (1.1- to 1.4-fold) in these liquid cultures. This modest expansion was significantly improved by the addition of SCM from the FBMD-1, L87/4 or L88/5 cell lines. Output CFC numbers were 6.8-, 5.8- and 9.9-fold higher, respectively, than the input values, while absolute CAFC week 2 to 4 numbers were 4.5-, 10.2- and 10.2-fold expanded, respectively. The addition of SCM also improved expansion of the more primitive CAFC week 6 to 8 stem cell subsets by 2.2-, 4.5- and 4.9-fold, respectively. The addition of granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage-CSF (GM-CSF), IL-1beta, IL-11 or macrophage inflammatory protein-1alpha to cultures containing IL-3, SCF and IL-6 could not explain the SCM effect and in all these combinations SCM addition further increased the recovery of HSC subsets. Similarly, addition of anti-cytokine antibodies (ie alpha-G-CSF, alpha-GM-CSF, alpha-IL-11, alpha-leukemia inhibitory factor) to liquid cultures containing IL-3, SCF, IL-6 and SCM could not neutralize the SCM effect. These data indicate that SCM significantly enhances expansion of primitive HSC and progenitor cells from CD34-selected PBSC in 7-day cultures and in synergistic combination with multiple cytokines at optimal concentrations. As a result, SCM is a useful component of short-term liquid culture procedures for clinical expansion or manipulation of primitive HSC.

Frequency analysis of human primitive haematopoietic stem cell subsets using a cobblestone area forming cell assay.

Stroma-dependent long-term bone marrow cultures (LTBMC) assay the ability of primitive haematopoietic stem cells (HSC) for long-term production of clonable progenitors. We have developed a limiting dilution type LTBMC assay allowing frequency analysis of transiently repopulating HSC and long-term culture initiating cells (LTC-IC) without the necessity to replate large numbers of wells. Normal or 5-FU-treated Ficoll bone marrow cells (BMC), or BMCs sorted on CD34 or HLA-DR expression, or Rh123 retention, (input range 40-70,000 CFU-GM/BFU-E/10(5) cells) were plated at limiting dilution on unirradiated adherent layers formed by a novel murine preadipose cell line (FBMD-1). The percentage of wells with at least one phase-dark haematopoietic clone (cobblestone area, CA) beneath the stromal layer was weekly determined for at least 8 weeks, and CA-forming cell (CAFC) frequencies were calculated using Poisson statistics. Parallel LTBMCs of the same samples were weekly assessed for supernate CFU-GM/BFU-E production. Weekly addition of rhIL-3 with rhG-CSF supported a high average clonogenic output per CA and dramatically increased CA size, but did not significantly alter the apparent CAFC frequency. The generation of CFU-GM per CA was constant over a period of 6 weeks with weekly means of eight normal BM samples, ranging between 5-16. At week 6 the mean CAFC frequency was 29 (1 SEM, 8.8)/10(5). Early appearing CAFC were highly sensitive to 5-FU, and were contained over the full Rh123 and HLA-DR fluorescence profile of CD34pos cells, whereas CAFC week 5-8 were predominantly contained in the CD34pos Rh123dull HLA-DRlow fraction in agreement with previously reported LTC-IC characteristics. In conclusion, the CAFC assay enumerates LTC-IC using a direct visual endpoint and allows study of LTC-IC heterogeneity with respect to progenitor cell generation per stem cell clone in various haematologic diseases.

Cell-mediated lympholysis studies in renal allograft recipients.

Cell-mediated lympholysis (CML) reactivity against the splenocytes of the kidney donor might be a good in vitro correlate of the homograft reaction. The present study was performed in an attempt to determine whether CML nonreactivity between unrelated donor-recipient combinations occur and, if so, under what conditions. We were able to show that CML nonreactivity occurs between unrelated donor-recipient combinations in 70% of the nonrejecting patients, whereas all of the rejecting patients were CML reactive. Patients with CML nonreactivity did clinically well more frequently than those that were CML reactive. The question as to whether or not such variables as HLA-A, B, and DR match and sex, the number of pretransplant blood transfusions, and the degree of presensitization, etc. predispose to the development of donor-specific CML nonreactivity was studied as well. Sex and compatibility for HLA-B antigens between donor and recipient might be such factors.

Renal transplant patients monitored by the cell-mediated lympholysis assay. Evaluation of its clinical value.

Donor-specific cytotoxic T cell activity was measured over a period of 5 years after transplantation using the cell-mediated lympholysis (CML) test in 124 recipients of unrelated kidney allografts who received conventional immunosuppressive therapy consisting of azathioprine and prednisone. Since patients with a functioning transplant frequently display donor-specific CML non-responsiveness in vitro, we addressed the question of whether the CML status has a predictive value regarding the graft prognosis at any time interval until 5 years posttransplantation. From log-rank type analyses we conclude that the estimated relative risk calculated over the whole follow-up period of a CML-responder in the category of transplant rejectors is 1.25 with 95% confidence bounds between 0.94 and 1.65. Measurements of CML responder status during follow-up seem to have only limited prognostic value, although the relative risk is borderline significant when the analysis is restricted to the period between 2 weeks and 6 months posttransplantation.

Blood lymphocytes from ankylosing spondylitis patients fail to induce disease-specific cytotoxic T lymphocytes.

The intriguing observation made by Geczy et al. (1) showing the possibility of generating specific ankylosing spondylitis--cytotoxic T lymphocytes by presenting HLA-B27+AS+ cells as antigen-specific stimulator cells prompted us (by using Geczy's approach) to identify cytotoxic T lymphocytes specific for this apparent B27+AS+ target structure. Peripheral blood mononuclear cells (PBMC) of 21 healthy B27+ individuals were stimulated in primary and in short-term cultures with PBMC of an HLA-identical sibling suffering from definite AS (n = 12). In addition, PBMC in vitro modified by "Geczy bacterial products" from two healthy B27+ individuals were used to stimulate B27+ AS- lymphocytes (either autologous or from a healthy HLA-identical sibling). Effector cells raised in primary AS- versus AS+ and AS- versus "modified B27" mixed lymphocyte culture combinations showed no proliferative nor cytotoxic activity at all. The scarcely observed cytotoxic reactivity of restimulated mixed lymphocyte culture was not restricted to AS+B27+ cells. These results demonstrate that PBMC from ankylosing spondylitis patients fail to induce disease-specific cytotoxic T lymphocytes and suggest that an ankylosing spondylitis--related "modified B27" structure does not exist, at least in the patient material tested.

Treatment of the symptoms of schizophrenia: a combined analysis of double-blind studies comparing risperidone with haloperidol and other antipsychotic agents.

Combined data on efficacy were available from 12 double-blind short-term (maximum 8 weeks) trials comparing risperidone and other antipsychotics in patients with chronic schizophrenia. Patients received risperidone (n = 1056) or other antipsychotics (n = 703). Haloperidol (n = 473) was the most frequently prescribed other antipsychotic. Efficacy assessments include the Positive and Negative Syndrome Scale (PANSS) total, subscale (positive symptoms, negative symptoms and general psychopathology), cluster (cognitive and affective symptoms) and item (anxiety and hostility) scores. At endpoint, the mean decrease from baseline in PANSS total scores was significantly greater for patients receiving risperidone (-20.9) than other antipsychotics (-16.2; P < 0.001), or the subset receiving haloperidol (-14.3; P < 0.001). Risperidone-treated patients showed a significantly greater decrease in the positive (P < 0.01), negative (P < 0.05) and general psychopathology (P < 0.001) scores than patients receiving other antipsychotics or haloperidol. Scores for cognition, affective symptoms, anxiety and hostility each improved significantly (P < 0.05) more for patients receiving risperidone than those receiving other antipsychotics or haloperidol. Efficacy data on patients with an acute exacerbation were available from seven trials (risperidone n = 372, other antipsychotics n = 285, including haloperidol n = 120). At endpoint, the mean decrease from baseline in PANSS total scores was significantly greater for patients receiving risperidone (-24.7) than other antipsychotics (-19.8, P < 0.01) including haloperidol (-19.8, P < 0.05). Risperidone-treated patients also showed a greater decrease in positive symptom scores (-7.8) than those receiving other antipsychotics (-6.3; P < 0.01) or haloperidol (-7.1). A > or = 20% reduction in PANSS total score with risperidone, haloperidol and other antipsychotics was achieved by 65.9%, 54.3% and 54.9%, respectively; a > or = 30% PANSS reduction by 54.0%, 46.6% and 46.5% of patients, respectively; and a > or = 40% reduction by 43.8%, 33.7% and 34.4% of patients, respectively. These findings are consistent with earlier findings that show risperidone is more efficacious than haloperidol for reducing the symptoms of schizophrenia.

The effect of mirtazapine in panic disorder: an open label pilot study with a single-blind placebo run-in period.

In this open label pilot study, we studied the efficacy of mirtazapine (Remeron) in panic disorder. Twenty-eight patients with a DSM-IV diagnosis of panic disorder, with or without agoraphobia (10 males/18 females), were included and 19 patients completed the study. The 15-week trial started with a 3-week single-blind placebo run-in period. After this run-in period, the 12-week active treatment phase started. As primary efficacy measures, we studied the decrease in the number of full symptom panic attacks and the number of patients completely free of panic during the last 3 weeks of the study. Seventy-four percent of the patients were considered responders, according to a decrease of at least 50% in panic attack frequency. All primary and secondary efficacy measures showed a significant improvement from the second week of active treatment onwards to endpoint. The main side-effects were different from the usual side-effects in selective serotonin reuptake inhibitors (SSRIs) (initial drowsiness, weight gain and pain in the legs). The results of this open label study in panic disorder suggest that mirtazapine seems to be a fast and effective treatment alternative for SSRIs in panic disorder.

Predictive value of early improvement in bipolar depression trials: a post-hoc pooled analysis of two 8-week aripiprazole studies.

OBJECTIVE: To evaluate the value of early improvement to predict treatment outcome in patients with bipolar depression. METHODS: Data were pooled from two aripiprazole, 8-week, randomized, double-blind, placebo-controlled trials in patients with bipolar depression without psychotic features to determine whether early improvement (≥20% reduction in Montgomery-Åsberg Depression Rating Scale (MADRS) Total score at Week 2 or 3) predicts later response (≥50% MADRS Total score reduction at Week 8) or remission (MADRS Total ≤10 at Week 8). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated (LOCF). Univariate and multivariate logistic regression models were used to evaluate early improvement and baseline demographic/clinical characteristics as predictors of response/remission. RESULTS: In total, 311 patients were randomized to placebo and 306 to aripiprazole. Predictive values of early improvement (≥20% MADRS Total score reduction) for remission with aripiprazole at Week 2/3, respectively, were: sensitivity 83%/94%; specificity 41%/33%; PPV 44%/45%; NPV 81%/91%. The corresponding values with placebo were as follows: sensitivity 70%/84%; specificity 60%/51%; PPV 50%/51%; NPV 77%/84%. Univariate linear regression showed that early improvement (≥15%, ≥20%, ≥25%, ≥30% at Week 3) was a significant potential predictor of remission. CONCLUSION: Absence of early improvement after 3 weeks of treatment reliably predicted non-response/non-remission at study endpoint with high sensitivity and NPV. In patients with <20% improvement after 21 days of aripiprazole monotherapy, treatment should be modified, as continued use is unlikely to result in response/remission. Clinical decision-making to optimize treatment course in bipolar I depression may be appropriate after as little as 2 weeks and certainly within the first 3 weeks of treatment.

Parental communication appears not to be an effective strategy to reduce smoking in a sample of Dutch adolescents.

This longitudinal study examined the reciprocal effects of the frequency of parent-adolescent communication on tobacco-related issues (smoking-specific communication), and adolescents' smoking. Participants were 428 Dutch older and younger siblings between 13 and 16 years old. Smoking-specific communication did not affect youth smoking in general; however, among younger, but not older, siblings, smoking-specific communication was associated with a higher likelihood of smoking over time. In addition, when adolescents already smoked parents started to talk more frequently about smoking-related issues with their older and younger adolescents later on. Neither the quality of smoking-specific communication, the quality of parent-adolescent relationship, nor parental smoking moderated these reciprocal effects. In conclusion, prevention campaigns encouraging parents to undertake smoking-specific communication might not be desirable.

The recognition of abnormal sex chromosome constitution by HLA-restricted anti-H-Y cytotoxic T cells and antibody.

Using the cell-mediated lympholysis (CML) technique, we studied lymphocytes of six individuals with discrepancies between the karyotypic and phenotypic sex. Two sets of cytotoxic T cells (CTLs) obtained from two multitransfused female aplastic anemia patients were used as typing reagents. These cells were previously shown to kill allogeneic target cells from HLA-A2- or B7-positive male donors. An antiserum obtained from one of the patients likewise killed HLA-A2 male lymphocytes. The six patients studied were selected for the required antigens. Positive reactions were obtained with lymphocytes from a 46,XY woman with pure gonadal dysgenesis and a 45,XO male. Target cells of the mother of the latter patient were also lysed. One individual with a 45,XO/46,X,del(Y)? karyotype was weakly positive, while three 46,XX males were completely negative. The reactivity of the HLA-A2-restricted H-Y-specific antibody showed the same discriminatory patterns. The results obtained by the HLA-restricted CTLs as well as by the antiserum did not correlate with the presence of testes as is the case in a different test system for the serologically detectable male (SDM) antigen in man. On the other hand, there was a correlation with the presence of cytologically detectable Y-chromosome material in five of the six individuals studied. The HLA-restricted CTLs and the antibody might recognize the classical transplantation antigen H-Y.