Cytokine release syndrome caused by antineoplastic treatment with CAR-T and T-cell engaging therapies

T-cell-based immunotherapy has recently evolved as a treatment option for a number of haematological malignancies and is also being developed in solid tumours. A common side effect of chimeric antigen T-cell therapy (CAR-T) and treatment with T-cell engagers is cytokine release syndrome (CRS), which is a potentially life-threatening condition characterized by release of inflammatory mediators. The treatment of CRS is similar to that of other hyper-inflammatory conditions and involves supportive treatment as well as immunosuppressive therapy. The risk of CRS can be mitigated by step-up dosing and immunosuppressive pre-treatment, as argued in this review.

Triple-Drug Graft-versus-Host Disease Prophylaxis after HLA-Matched Unrelated Donor Nonmyeloablative Allogenic Hematopoietic Stem Cell Transplantation

Adding sirolimus to graft-versus-host disease (GVHD) prophylaxis with cyclosporin and mycophenolate mofetil (MMF) reduced the risk of grade II-IV acute GVHD after nonmyeloablative (NMA) allogenic hematopoietic stem cell transplantation (HSCT) with an HLA-matched unrelated donor in a randomized clinical trial. We analyzed real-life data to investigate the impact of implementing the triple-drug regimen with cyclosporin, MMF and sirolimus as standard GVHD prophylaxis after NMA HSCT with an HLA-matched unrelated donor at our institution. We studied all adult patients (age ≥18 years) who underwent NMA HSCT with an HLA-matched unrelated donor at Rigshospitalet, Copenhagen University Hospital, Denmark between 2018 and 2021 and received GVHD prophylaxis with cyclosporin, MMF and sirolimus (triple-drug group [TDG]). Comparisons were made with a historical cohort who received tacrolimus and MMF as GVHD prophylaxis after HLA-matched unrelated donor NMA HSCT between 2014 and 2017 (control group [CG]). Outcomes were grade II-IV and grade III-IV acute GVHD, chronic GVHD, relapse, nonrelapse mortality (NRM) and overall survival (OS). A total of 264 patients were included (TDG, n = 137; CG, n = 127). Median age was 66 years (interquartile range [IQR], 58 to 69 years) in the TDG and 63 years (IQR, 57 to 68 years) in the CG. Acute myeloid leukemia and myelodysplastic syndrome were the most frequent indications for HSCT in both groups (TDG, 33% and 23%, respectively; CG, 36% and 22%, respectively). The cumulative incidence at day +110 of grade II-IV GVHD was 17% (95% confidence interval [CI] 11% to 23%) in the TDG versus 29% (95% CI, 21% to 37%) in the CG (P = .02, Gray's test) and that of grade III-IV acute GVHD was 3% (95% CI, 0 to 6%) versus 5% (95% CI, 1% to 8%), respectively (P = .4, Gray's test). In a Cox regression model adjusted for age, donor age and female donor to male recipient the risk of grade II-IV acute GVHD was lower in the TDG compared to the CG (hazard ratio [HR], .51; 95% CI .30 to .86; P = .01). The 2-year OS was 77% (95% CI, 70% to 84%) in the TDG and 69% (95% CI, 61% to 77%) in the CG (P = .04), and this difference remained significant after adjustment for age and Karnofsky Performance Status (HR, .65; 95% CI, .42 to .99; P = .04). The 2-year cumulative incidences of chronic GVHD, relapse and NRM were 60% (95% CI, 51% to 69%), 21% (95% CI, 13% to 28%), and 12% (95% CI, 6% to 17%), respectively, in the TDG and 62% (95% CI, 54% to 71%), 27% (95% CI, 19% to 35%) and 14% (95% CI, 8% to 20%), respectively, in the CG. Multivariable analyses revealed no difference in the risk of chronic GVHD (HR, .91; 95% CI, .65 to 1.26; P = .56), relapse (HR, .70; 95% CI, .42 to 1.15; P = .16) or NRM (HR, .56; 95% CI, .31 to 1.05; P = .07). After changing the standard GVHD prophylaxis in patients undergoing NMA HSCT with an HLA-matched unrelated donor from tacrolimus and MMF to cyclosporin, MMF and sirolimus, we observed a reduction in the incidence of grade II-IV acute GVHD and improved 2-year OS.

Autologous hematopoietic stem cell transplantation of patients with aggressive relapsing-remitting multiple sclerosis: Danish nation-wide experience

BACKGROUND

Autologous hematopoietic stem cell treatment (AHSCT) is considered an effective treatment option for patients with aggressive relapsing-remitting multiple sclerosis (RRMS). Still there are few randomized and controlled studies of AHSCT to shed light on the safety and efficacy of the treatment, and therefore experiences from single centers are important.

AIM

To describe the Danish experience with AHSCT regarding patient characteristics, safety, and efficacy.

METHOD

Nationwide retrospective single center study of patients with multiple sclerosis (MS) treated with AHSCT.

RESULTS

A total of 32 patients were treated with AHSCT from May 2011 to May 2021. Seven were treated with carmustine, etoposide, cytarabine arabinoside, and melphalan (BEAM) as well as antithymocyte globulin (ATG). Twenty-five patients were treated with cyclophosphamide (CY) and ATG. In the whole cohort, relapse-free survival (RFS) was 77% (95% CI: 64-94%), worsening-free survival (WFS) was 79% (95% CI: 66-96%), MRI event-free survival (MFS) was 93% (95% CI: 85-100%), and no evidence of disease (NEDA-3) was 69% (95% CI: 54-89%) at the end of year two post-AHSCT. We had no treatment related mortality and only few severe adverse events (AEs).

CONCLUSION

AHSCT of patients with aggressive RRMS was an effective and relatively safe treatment with few serious AEs and no mortality in Danish patients.

Pre-transplantation vitamin E levels and acute graft-versus-host disease after non-myeloablative allogeneic hematopoietic cell transplantation

BACKGROUND

Low pre-transplantation plasma vitamin E levels have been associated with increased risk of acute graft-versus-host disease (GvHD) after myeloablative allogeneic hematopoietic cell transplantation (allo-HCT). We aimed to investigate the association between pre-transplantation plasma vitamin E levels and acute GvHD in patients undergoing allo-HCT with non-myeloablative conditioning.

METHODS

In a cohort of 194 adults who underwent non-myeloablative allo-HCT at Rigshospitalet between July 2015 and December 2019, we measured pre-transplantation plasma vitamin E levels by high-performance liquid chromatography in stored plasma samples. Univariable ordinary least squares linear models were used to investigate associations between vitamin E levels and patient characteristics. A multivariable logistic regression model was used to estimate the association between vitamin E levels and grade II-IV acute GvHD, adjusted for recipient age, donor age, female-male donor-recipient pairing, and donor type.

RESULTS

The median (Q1, Q3) pre-transplantation plasma vitamin E level was 32.3 (26.4, 40.4) μmol/L. No patients had a vitamin E level below the normal reference range. Vitamin E levels were higher in females (mean difference: 8.0 μmol/L, 95% confidence interval [CI]: 4.9, 11.1 μmol/L) and in patients transplanted for acute leukemia (mean difference: 6.2 μmol/L, CI: 3.0, 9.4 μmol/L). Grade II-IV acute GvHD developed in 33 (17%) patients. Patients who developed acute GvHD had similar pre-transplantation vitamin E levels compared with patients who did not develop grade II-IV acute GvHD (mean difference: 0.7 μmol/L, bootstrap CI: -3.3, 4.7 μmol/L). In the adjusted logistic regression model, an increase in the pre-transplantation vitamin E level from 26.4 (Q1) to 40.4 (Q3) μmol/L was associated with an odds ratio of grade II-IV acute GvHD of 1.17 (CI: 0.64, 2.12).

CONCLUSIONS

Contrary to the previously reported association between pre-transplantation vitamin E levels and acute GvHD after myeloablative allo-HCT, we did not find support for an association in patients who received non-myeloablative conditioning. The potential protective effects of vitamin E may not be efficacious in the reduced inflammatory response following non-myeloablative conditioning.

Improved survival after allogeneic transplantation for acute lymphoblastic leukemia in adults: a Danish population-based study

We investigated trends of survival in a population-based cohort study of all 181 adults who received HCT for ALL in Denmark between 2000-2019. Patients had a median (min-max) age of 36 (18-74) years at HCT and were followed for a median of eight years. Overall survival (OS) improved over time with an estimated 2-year OS of 49% (CI 27-66%) in year 2000 versus 77% (CI 59-88%) in year 2019. More patients achieved cure over time (OR for cure per year 1.07, CI 1.00-1.15), while the rate of death in non-cured patients remained stable (HR of excess mortality per year 0.99, CI 0.93-1.06). Relapse decreased over time (HR 0.92 per year, CI 0.87-0.98), whereas non-relapse mortality did not change notably (HR 0.98 per year, CI 0.93-1.04). In conclusion, survival after HCT in adults with ALL has improved over the past two decades, primarily due to more patients achieving cure.

[Bone marrow transplantation and chimeric antigen receptot T cellular therapy]

Malignant hematologic diseases resistant to chemotherapy can be cured by immune cellular therapy. Bone marrow transplantation (BMT) elicits a "pan-immunologic" attack, whereas therapy with chimeric antigen receptor (CAR)-T is a targeted attack. The immunologic activity after BMT can be adjusted by selection of donor cells before transplantation, or with post-BMT sequential chemotherapy. Many haematologic diseases are clonal, and the development of CAR-T cellular therapy directed against a variety of epitopes is under development as summarised in this review.

Pre-transplantation plasma vitamin D levels and acute graft-versus-host disease after myeloablative hematopoietic cell transplantation in adults

BACKGROUND

The association between vitamin D and acute graft-versus-host disease (GvHD) remains controversial, especially for patients receiving myeloablative conditioning.

METHODS

We measured pre-transplantation plasma vitamin D (25-hydroxyvitamin D₃ + D₂) levels by competitive electrochemiluminescence in plasma samples from 116 adult patients who underwent a myeloablative allogeneic transplantation at Rigshospitalet, Copenhagen between July 2015 and August 2018.

RESULTS

The median (Q1, Q3) pre-transplantation plasma vitamin D level was 64 (47, 85) nmol/L (normal range: 50-160 nmol/L). Vitamin D insufficiency (<50 nmol/L) and moderate deficiency (<25 nmol/L) were observed in 29% and 8% of patients, respectively. No patients had a severe deficiency (<12 nmol/L). Pre-transplantation vitamin D levels were slightly higher in patients who later developed grade II-IV acute GvHD (mean difference: 8.1 nmol/L), but the 95% confidence interval [CI] encompassed clinically insignificant differences (CI: -2.2, 19.2 nmol/L). From multivariable logistic regression, we found that a patient with a pre-transplantation vitamin D level of 85 nmol/L (Q3) had 1.5 times higher odds of grade II-IV acute GvHD than a patient with a level of 47 nmol/L (Q1; CI of odds ratio: 0.84, 2.7; adjusted for patient age, donor type, use of anti-thymocyte globulin, and use of 12 Gy total-body irradiation). Patients with pre-transplantation vitamin D insufficiency (N = 34) had a cumulative incidence of grade II-IV acute GvHD similar to that of patients with vitamin D sufficiency (26% [CI: 11%, 42%] versus 35% [CI: 25%, 46%], respectively).

CONCLUSIONS

Our data did not support an association between pre-transplantation vitamin D levels or vitamin D insufficiency and acute GvHD in adult patients receiving myeloablative conditioning.

Allogeneic hematopoietic cell transplantation with non-myeloablative conditioning for patients with hematologic malignancies: Improved outcomes over two decades

We have used a non-myeloablative conditioning regimen for allogeneic hematopoietic cell transplantation for the past 20 years. During that period, changes in clinical practice have been aimed at reducing morbidity and mortality from infections, organ toxicity, and graft-versus-host disease. We hypothesized that improvements in clinical practice led to better transplantation outcomes over time. From 1997–2017, 1,720 patients with hematologic malignancies received low-dose total body irradiation ± fludarabine or clofarabine before transplantation from HLAmatched sibling or unrelated donors, followed by mycophenolate mofetil and a calcineurin inhibitor ± sirolimus. We compared outcomes in three cohorts by year of transplantation: 1997–2003 (n=562), 2004–2009 (n =594), and 2010–2017 (n=564). The proportion of patients ≥60 years old increased from 27% in 1997–2003 to 56% in 2010–2017, and with scores from the Hematopoietic Cell Transplantation Comorbidity Index of ≥3 increased from 25% in 1997–2003 to 45% in 2010–2017. Use of unrelated donors increased from 34% in 1997–2003 to 65% in 2010–2017. When outcomes from 2004–2009 and 2010–2017 were compared to 1997–2003, improvements were noted in overall survival (P=0.0001 for 2004–2009 and P≤0.0001 for 2010–2017), progression-free survival (P=0.002 for 2004–2009 and P<0.0001 for 2010–2017), non-relapse mortality (P<0.0001 for 2004– 2009 and P<0.0001 for 2010–2017), and in rates of grades 2–4 acute and chronic graft-versus-host disease. For patients with hematologic malignancies who underwent transplantation with non-myeloablative conditioning, outcomes have improved during the past two decades. Trials reported are registered under clinicaltrials gov. Identifiers: NCT00003145, NCT00003196, 005803, NCT00006251, NCT00014235, NCT00027820, NCT00031655, NCT00036738, NCT00045435, NCT00052546, NCT00060424, NCT00075478, NCT00078858, NCT00089011, NCT00104858, NCT00105001, NCT00110058, NCT00397813, NCT00793572, NCT01231412, NCT01252667, NCT01527045.

Functional immune reconstitution early after allogeneic haematopoietic cell transplantation: A comparison of pre- and post-transplantation cytokine responses in stimulated whole blood

We aimed to use a novel standardized whole-blood stimulation system to evaluate differences in the functional immune reconstitution in patients early after allogeneic haematopoietic cell transplantation (HCT). Between April and September 2018, 30 patients undergoing HCT had whole blood samples collected around day -21 (day 0 being the day of haematopoietic cell infusion) and day +28. Whole blood was transferred to TruCulture assays comprising prefilled incubation tubes with cell culture medium and a standardized stimulus. We used a panel of four stimuli (lipopolysaccharide, resiquimod, heat-killed Candida albicans and polyinosinic:polycytidylic acid) and a blank, designed to evaluate the function of critical extra- and intracellular immunological signalling pathways. For each stimulus, the cytokine response was assessed by the concentration of interferon-γ, interleukin (IL)-12p40, IL-10, IL-1β, IL-6, IL-8, IL-10, IL-12p40, IL-17A and tumour necrosis factor-α using a multiplex Luminex assay. Pre-HCT cytokine responses were globally decreased across several different stimuli. Despite patients receiving immunosuppressive prophylaxis at the time, post-HCT cytokine responses were higher and less intercorrelated than pre-HCT responses, also after adjusting for differences in the leukocyte differential counts. For the resiquimod and heat-killed Candida albicans stimuli, we identified a cluster of patients in whom post-HCT responses were lower than average across several cytokines, indicating a possible functional immune deficiency. Our findings suggest that the standardized whole blood stimulation system can be used to reveal heterogeneity in the in vitro cytokine responses to various stimuli after HCT. Larger studies are needed to address if the functional immune reconstitution after HCT can predict the risk of infections.

Outcomes following second allogeneic haematopoietic cell transplantation in patients with myelofibrosis: a retrospective study of the Chronic Malignancies Working Party of EBMT

Therapeutic management of patients with primary or secondary myelofibrosis (MF) who experience relapse or graft failure following allogeneic haematopoietic cell transplantation (allo-HCT) remains heterogeneous. We retrospectively analyzed 216 patients undergoing a second allo-HCT for either relapse (56%) or graft failure (31%) between 2010 and 2017. Median age was 57.3 years (range 51-63). The same donor as for the first allo-HCT was chosen in 66 patients (31%) of whom 19 received an HLA-identical sibling donor, whereas a different donor was chosen for 116 patients (54%). Median follow-up was 40 months. Three-year overall survival (OS) and relapse-free survival (RFS) were 42% and 39%, respectively. Three-year non-relapse mortality (NRM) and relapse rates were 36% and 25%, respectively. Grade II-IV and III-IV acute GVHD occurred in 25% and 11% of patients, respectively, and the 3-year incidence of chronic GVHD was 33% including 14% for extensive grade. Graft-failure incidence at 1 year was 14%. In conclusion, our data suggest that a second allo-HCT is a potential option for patients failing first allo-HCT for MF albeit careful patient assessment is fundamental to identify individual patients who could benefit from this approach.

Vitamin E and acute graft-versus-host disease after myeloablative allogeneic hematopoietic cell transplantation

OBJECTIVES

Vitamin E has antioxidant and immunomodulatory effects that might influence the development of acute graft-versus-host disease (GvHD). We investigated the association between plasma vitamin E levels and acute GvHD.

METHODS

We studied 115 adults who underwent myeloablative allogeneic hematopoietic cell transplantation between July 2015 and August 2018. Vitamin E was measured by high-performance liquid chromatography in stored plasma samples obtained pre-transplantation at day -23 (±15 days) and post-transplantation at day +28 (±3 days).

RESULTS

Pre-transplantation vitamin E levels were inversely associated with grade II-IV acute GvHD (hazard ratio 0.68 per 10 µmol/L increase, 95% confidence interval [CI]: 0.47-0.98). The association remained after adjustment for known prognostic factors for acute GvHD. Patients with levels below the median had a cumulative incidence of grade II-IV acute GvHD of 46% (CI: 33-59%) versus 21% (CI: 10-32%) in patients with levels above the median. No clear association with non-relapse mortality, relapse, or chronic GvHD was found. Post-transplantation vitamin E levels (measured in 72 [63%] patients) were correlated with pre-transplantation levels (ρ = .31) but were not associated with subsequent grade II-IV acute GvHD.

CONCLUSIONS

High pre-transplantation vitamin E levels were associated with less acute GvHD.

Improved Relapse-Free Survival in Patients With High Natural Killer Cell Doses in Grafts and During Early Immune Reconstitution After Allogeneic Stem Cell Transplantation

Mature immunocompetent cells from the stem cell graft as well as early robust immune reconstitution are essential for the graft-vs. -tumor (GVT) effect to eliminate residual malignant cells after allogeneic hematopoietic stem cell transplantation (HSCT). In this prospective study we characterized graft composition of T- and NK cell subsets in 88 recipients of peripheral blood stem cell grafts with multicolor flowcytometry. Our primary aim was to analyze the impact of graft composition on immune reconstitution and clinical outcomes after transplantation. Patients transplanted with graft NK cell doses above the median value of 27 × 10⁶/kg had significantly increased relapse-free-survival compared to patients transplanted with lower doses, HR 2.12 (95% CI 1.01-4.45, p = 0.04) Peripheral blood concentrations of NK cells obtained from donors before G-CSF mobilization were significantly correlated to graft NK cell doses (Spearman's ρ 0.53, p = 0.03). The dose of transplanted NK cells/kg correlated significantly with NK cell concentrations in patients early after transplantation (Spearman's ρ 0.26, p = 0.02, and ρ = 0.35, p = 0.001 for days 28 and 56, respectively). Early immune reconstitution above median values of NK cells was significantly associated with improved relapse-free survival (HR 2.84 [95% CI 1.29-6.28], p = 0.01, and HR 4.19 [95% CI 1.68-10.4], p = 0.002, for day 28 and 56, respectively). Early concentrations above the median value of the mature effector CD56dim NK cell subset were significantly associated with decreased relapse incidences at 1 year, 7% (95% CI 1.8-17) vs. 28% (95% CI 15-42), p = 0.04, and 7% (95% CI 1.8-18) vs. 26% (95% CI 14-40) %, p = 0.03, for days 28 and 56, respectively. The results suggest a protective effect of high doses of NK cells in grafts and during early immune reconstitution and support the perception of NK cells as innate effector cells with anti-tumor effects in the setting of allogeneic stem cell transplantation.

[Chimeric antigen receptor T-cell therapy]

Although treatment of haematological cancer has improved significantly during the latest decades, the prognosis is poor in case of relapse or refractory disease. This review describes the chimeric antigen receptor (CAR) T-cell therapy, which has emerged as a new promising treatment principle, in which the patient's own T-cells are genetically modified to recognise cancer cells. The possible side effects are usually only transient. A commercial CD19 CAR T-cell product has recently been approved as treatment for acute lympho-blastic leukaemia in children and young adults in Denmark, and a non-commercial CAR T-cell production is being established.

[Autologous haematopoietic stem cell transplantation of patients with multiple sclerosis]

Immunosuppression with chemotherapy followed by autologous haematopoietic stem cell transplantation has proven to be an effective long-term treatment for younger patients with relapsing-remitting multiple sclerosis and clinical as well as radiological evidence of high disease activity. The conditioning regimen can be of either high, intermediate or low intensity. Due to the safety profile and favourable efficacy measures, the low intensity regimen cyclophosphamide + anti-thymocyte globulin is currently used in Denmark as standard regimen.

Improved Overall Survival, Relapse-Free-Survival, and Less Graft-vs.-Host-Disease in Patients With High Immune Reconstitution of TCR Gamma Delta Cells 2 Months After Allogeneic Stem Cell Transplantation

T-cell receptor (TCR) γδ cells are perceived as innate-like effector cells with the possibility of mediating graft-vs. -tumor (GVT) without causing graft-vs.-host disease (GVHD) in the setting of hematopoietic allogeneic stem cell transplantation (HSCT). We conducted a prospective study to assess the clinical impact of TCR γδ cell immune reconstitution on overall survival, relapse-free-survival, relapse and GVHD. The impact of CD3, CD4, and CD8 T cells together with NK cells including subtypes were analyzed in parallel. A total of 108 patients with hematological malignancies transplanted with HLA-matched, T cell replete stem cell grafts were included for analyses of absolute concentrations of CD3, CD4, and CD8 positive T cells and NK cells together with a multi-color flow cytometry panel with staining for TCRαβ, TCRγδ, Vδ1, Vδ2, CD3, CD4, CD8, HLA-DR, CD196, CD45RO, CD45RA, CD16, CD56, CD337, and CD314 at 28, 56, 91, 180, and 365 days after transplantation. Immune reconstitution data including subsets and differentiation markers of T and NK cells during the first year after transplantation was provided. Patients with TCR γδ cell concentrations above the median value of 21 (0–416) × 10⁶ cells/L 56 days after transplantation had significantly improved overall survival (p = 0.001) and relapse-free survival (p = 0.007) compared to patients with concentrations below this value. When day 56 cell subset concentrations were included as continuous variables, TCR γδ cells were the only T cell subsets with a significant impact on OS and RFS; the impact of TCR γδ cells remained statistically significant in multivariate analyses adjusted for pre-transplant risk factors. The risk of death from relapse was significantly decreased in patients with high concentrations of TCR γδ cells 56 days after transplantation (p = 0.003). Also, the risk of acute GVHD was significantly lower in patients with day 28 TCR γδ cell concentrations above the median of 18 × 10⁶ cells/L compared to patients with low concentrations (p = 0.01). These results suggest a protective role of TCR γδ cells in relapse and GVHD and encourage further research in developing adaptive TCR γδ cell therapy for improving outcomes after HSCT.

Mononuclear Cell Telomere Attrition Is Associated with Overall Survival after Nonmyeloablative Allogeneic Hematopoietic Cell Transplantation for Hematologic Malignancies

After allogeneic hematopoietic cell transplantation (allo-HCT), transplanted cells rapidly undergo multiple rounds of division. This may cause extensive telomere attrition, which could potentially prohibit further cell division and lead to increased mortality. We therefore characterized the development in telomere length after nonmyeloablative allo-HCT in 240 consecutive patients transplanted because of hematologic malignancies and tested the hypothesis that extensive telomere attrition post-transplant is associated with low overall survival. Telomere length was measured using quantitative PCR in mononuclear cells obtained from donors and recipients pretransplant and in follow-up samples from recipients post-transplant. Telomere attrition at 9 to 15 months post-transplant was calculated as the difference between recipient telomere length at 9 to 15 months post-transplant and donor pretransplant telomere length, divided by donor pretransplant telomere length. Although allo-HCT led to shorter mean telomere length in recipients when compared with donors, recipients had longer mean telomere length 9 to 15 months post-transplant than they had pretransplant. When compared with donor telomeres, recipients with extensive telomere attrition at 9 to 15 months post-transplant had low overall survival (10-year survival from 9 to 15 months post-transplant and onward: 68% in the tertile with least telomere attrition, 57% in the middle tertile, and 39% in the tertile with most attrition; log-rank P = .01). Similarly, after adjusting for potential confounders, recipients with extensive telomere attrition had high all-cause mortality (multivariable adjusted hazard ratio, 1.84 per standard deviation of telomere attrition at 9 to 15 months post-transplant; 95% confidence interval, 1.25 to 2.72; P = .002) and high relapse-related mortality (subhazard ratio, 2.07; 95% confidence interval, 1.14 to 3.76; P = .02). Taken together, telomere attrition may be a clinically relevant marker for identifying patients at high risk of mortality.

Classification of death causes after transplantation (CLASS): Evaluation of methodology and initial results

Correct classification of death causes is an important component of transplant trials.We aimed to develop and validate a system to classify causes of death in hematopoietic stem cell (HSCT) and solid organ (SOT) transplant recipients.Case record forms (CRF) of fatal cases were completed, including investigator-designated cause of death. Deaths occurring in 2010 to 2013 were used for derivation; and were validated by deaths occurring in 2013 to 2015. Underlying cause of death (referred to as recorded underlying cause) was determined through a central adjudication process involving 2 external reviewers, and subsequently compared with the Danish National Death Cause Registry.Three hundred eighty-eight recipients died 2010 to 2015 (196 [51%] SOT and 192 [49%] HSCT). The main recorded underlying causes of death among SOT and HSCT were classified as cancer (20%, 48%), graft rejection/failure/graft-versus-host-disease (35%, 28%), and infections (20%, 11%). Kappa between the investigator-designated and the recorded underlying cause of death was 0.74 (95% CI 0.69-0.80) in derivation and comparable in the validation cohort. Death causes were concordant with the Danish National Death Cause Registry in 37.2% (95% CI 31.5-42.9) and 38.4% (95% CI 28.8-48.0) in the derivation and validation cohorts, respectively.We developed and validated a method to systematically and reliably classify the underlying cause of death among transplant recipients. There was a high degree of discordance between this classification and that in the Danish National Death Cause Registry.

Microarray analysis of neonatal rat anteroventral periventricular transcriptomes identifies the proapoptotic Cugbp2 gene as sex-specific and regulated by estradiol

Sexually dimorphic neural structures regulate numerous gender-specific functions including luteinizing hormone (LH) release patterns. The female cyclic surge pattern of release is controlled by the anteroventral periventricular nucleus (AVPV), a preoptic area (POA) region that is significantly smaller in males. The prevailing hypothesis used to explain these differences in structure and function is that a "default" feminine AVPV is defeminized by exposure to estradiol (E2), a metabolite of testosterone (T) produced by the perinatal testes. E2 exposure then culminates in apoptosis in the male AVPV, but the upstream pathways are poorly understood. To address this issue, we compared AVPV transcriptomes of postnatal day 2 (PND2) males and females with those of females treated with E2 or vehicle. Only six of 89 sex-specific genes were also regulated by E2 in the PND2 AVPV and E2 regulated over 280 genes not found to be sex-specific. Of targets that changed similarly in males and E2-treated females, the gene encoding CUG triplet repeat, RNA-binding protein 2 (Cugbp2), a proapoptotic protein, showed the highest fold-changes. Quantitative polymerase chain reaction (QPCR) studies confirmed higher mRNA levels in PND2 male and E2-treated female AVPVs wherein E2 induces apoptosis. POA mapping studies detected Cugbp2 mRNA in the AVPV and in the sexually dimorphic nucleus of the POA (SDN-POA); however, sex differences and E2 effects occurred only in the AVPV. Combined with evidence that Cugbp2 regulates splicing and translation of mRNAs linked to sexual differentiation, we propose that this gene mediates E2-dependent effects on AVPV defeminization.

TRAF2 is a biologically important necroptosis suppressor

Tumor necrosis factor α (TNFα) triggers necroptotic cell death through an intracellular signaling complex containing receptor-interacting protein kinase (RIPK) 1 and RIPK3, called the necrosome. RIPK1 phosphorylates RIPK3, which phosphorylates the pseudokinase mixed lineage kinase-domain-like (MLKL)-driving its oligomerization and membrane-disrupting necroptotic activity. Here, we show that TNF receptor-associated factor 2 (TRAF2)-previously implicated in apoptosis suppression-also inhibits necroptotic signaling by TNFα. TRAF2 disruption in mouse fibroblasts augmented TNFα-driven necrosome formation and RIPK3-MLKL association, promoting necroptosis. TRAF2 constitutively associated with MLKL, whereas TNFα reversed this via cylindromatosis-dependent TRAF2 deubiquitination. Ectopic interaction of TRAF2 and MLKL required the C-terminal portion but not the N-terminal, RING, or CIM region of TRAF2. Induced TRAF2 knockout (KO) in adult mice caused rapid lethality, in conjunction with increased hepatic necrosome assembly. By contrast, TRAF2 KO on a RIPK3 KO background caused delayed mortality, in concert with elevated intestinal caspase-8 protein and activity. Combined injection of TNFR1-Fc, Fas-Fc and DR5-Fc decoys prevented death upon TRAF2 KO. However, Fas-Fc and DR5-Fc were ineffective, whereas TNFR1-Fc and interferon α receptor (IFNAR1)-Fc were partially protective against lethality upon combined TRAF2 and RIPK3 KO. These results identify TRAF2 as an important biological suppressor of necroptosis in vitro and in vivo.

Nonclassical progesterone signalling molecules in the nervous system

Progesterone (P4) regulates a wide range of cognitive, neuroendocrine, neuroimmune and neuroprotective functions. Therefore, it is not surprising that this ovarian hormone acts through multiple receptors. Ever since the 1980s, studies investigating the neural effects of P4 have focused mainly on genomic and nongenomic actions of the classical progestin receptor (PGR). More recently, two groups of nonclassical P4 signalling molecules have been identified: (i) the class II progestin and adipoQ receptor (PAQR) family, which includes PAQR 5, 6, 7, 8 and 9, also called membrane progestin receptor α (mPRα; PAQR7), mPRβ (PAQR8), mPRγ (PAQR5), mPRδ (PAQR6) and mPRε (PAQR9), and (ii) the b5-like haeme/steroid-binding protein family, which includes progesterone receptor membrane component 1 (Pgrmc1), Pgrmc2, neudesin and neuferricin. In this review, we describe the structures, neuroanatomical localisation and signalling mechanisms of these molecules. We also discuss gonadotrophin-releasing hormone regulation as an example of a physiological function regulated by multiple progesterone receptors but through different mechanisms.

17β-estradiol and progesterone regulate multiple progestin signaling molecules in the anteroventral periventricular nucleus, ventromedial nucleus and sexually dimorphic nucleus of the preoptic area in female rats

Recent work identified novel progestin signaling molecules, including progesterone receptor membrane component 1 (Pgrmc1), Pgrmc2, serpine mRNA binding protein 1 (Serbp1), progestin and adiponectin receptors 7 (Paqr7) and Paqr8. These molecules mediate rapid progesterone (P(4)) effects in non-neural tissue and we recently mapped their expression in the brain. Many rapid effects of P(4) require 17β-estradiol (E(2)) and P(4) priming; therefore, we examined the effects of ovarian hormones on the expression of these non-classical progestin signaling molecules. We focused specifically on the anteroventral periventricular nucleus (AVPV), the sexually dimorphic nucleus of the preoptic area (SDN-POA) and the ventrolateral portion of the ventromedial nucleus (VMNvl). These brain nuclei are important for female reproduction. Ovariectomized adult female rats were implanted with capsules containing sesame oil or E(2), and injected 48 h later with sesame oil or P(4). Brains were collected 8 h later and RNA was isolated from the AVPV, SDN-POA and VMNvl. We assessed the effects of ovarian hormones on mRNA levels using quantitative polymerase chain reaction (QPCR). In the AVPV, Serbp1 mRNA levels were increased by P(4) in the presence of E(2), and Paqr8 was downregulated by P(4) alone. In the SDN-POA, combined E(2) and P(4) increased Pgrmc1 and Serbp1 mRNA levels, and E(2) alone increased Paqr8 mRNA levels. Finally, in the VMNvl, P(4) increased mRNA levels encoding Pgrmc1, Pgrmc2 and Serbp1, and the combination of E(2) and P(4) increased Pgrmc1 and Serbp1 mRNA levels. Paqr7 was not regulated by E(2) or P(4) in any brain region examined. In summary, we showed that ovarian hormones regulate novel progestin signaling molecules in brain regions important for the neuroendocrine control of reproduction.

The genetic variation of the human HMGB1 gene

High-mobility group box 1 protein (HMGB1) is a nuclear DNA-binding protein, which also functions as a pleiotropic cytokine, implicated in the pathology of several different immune-mediated diseases. The purpose of this study was to examine the HMGB1 gene for putative polymorphisms in 103 healthy Caucasian Danish blood donors. A total of six polymorphisms and four mutations were identified in the HMGB1 gene. Subsequent MatInspector estimation revealed that several polymorphisms might have a potential regulatory impact on HMGB1 transcription. This study has characterized genetic variations in the HMGB1 gene locus, which may have a regulating role in the expression of HMGB1, providing the basis for molecular investigations of the HMGB1 gene in different disease settings.

Alloreactivity as therapeutic principle in the treatment of hematologic malignancies. Studies of clinical and immunologic aspects of allogeneic hematopoietic cell transplantation with nonmyeloablative conditioning

Allogeneic hematopoietic cell transplantation (HCT) represents a potentially curative treatment modality in a range of hematologic malignancies. High-dose myeloablative radio-chemotherapy has conventionally been used as part of the preparative regimen before HCT for two reasons: it has a profound immunosuppressive effect on the host, limiting the ability to reject the graft and it has substantial anti-tumor efficacy. Graft rejection is an example of alloreactivity as alloreactivity denotes the immunologic reactions that occur when tissues are transplanted between two individuals within the same species. If the immune system of the host is suppressed to a degree where rejection does not occur, the possibility arises that immunocompetent donor cells can attack the recipient tissues. This phenomenon is termed Graft-versus-Host disease (GVHD) if healthy tissues of the host are attacked and the Graft-versus-Tumor (GVT) effect if the malignant cells are the targets of the reaction. Clinical studies have shown that patients who develop GVHD have a lower risk of relapse of the malignant disease and that donor lymphocyte infusion can induce durable remissions in patients with relapsed disease following the transplant. These observations indicate that a GVT effect can be present following allogeneic HCT and that this effect, like GVHD, is an alloreactive response. The toxicity of HCT with myeloablative conditioning is considerable and this limits the use of this procedure to patients below 50-60 years of age. A large proportion of the patients with hematologic malignancies are older than 60 years at diagnosis and they are therefore not eligible for this treatment. During the last decade, conditioning regimens that are nonmyeloablative or have reduced intensity have been developed. The purpose of this development has been to extend the use of allogeneic HCT to older patients and to patients who due to the malignant disease or to comorbidities are unable to tolerate myeloablative conditioning. In allogeneic HCT with nonmyeloablative conditioning the curative potential relies entirely on the ability of the donor cells to elicit a GVT effect. Allogeneic HCT with nonmyeloablative conditioning was introduced at Department of Hematology at Rigshospitalet in March 2000. The results of this treatment modality have been promising and we and others have shown that durable remissions can be obtained in patients who are heavily pretreated. One of the goals of allogeneic HCT with nonmyeloablative conditioning was to perform both the actual transplant procedure and the clinical follow up in the outpatient setting. In the first 30 patients transplanted at Rigshospitalet, we observed that the transplant itself and the first weeks post transplant could be performed as an outpatient procedure in a number of patients. However, all the patients were admitted and the median duration of hospitalization was 44 days during the first year post transplant. Complications such as infections and GVHD were common causes of hospitalization and studies from other centers have shown that infections, GVHD and relapse of the malignancy are the major obstacles to a good result of allogeneic HCT with nonmyeloablative conditioning. One way to improve the results of this treatment would therefore be to reduce the incidence of GVHD without compromising the GVT effect. In HCT with nonmyeloablative conditioning the relatively well-defined antineoplastic effect of high-dose myeloablative radio-chemotherapy is substituted with the alloreactive effect of the donor cells. Because the level of alloreactivity varies widely between different donor-recipient pairs, the ability to monitor the level of alloreactivity following the transplant would therefore be desirable. To this end we have investigated the ability of different immunologic and molecular methods to quantify the level of ongoing alloreactivity following the transplant. By simultaneous determination of the fraction of T cells of donor origin (donor T-cell chimerism) and the total number of T cells in the peripheral blood, we observed that patients with a high number of donor CD8 + T cells on day +14 had a high risk of acute GVHD. Other studies have shown that the level of donor T-cell chimerism early after transplant predicts the development of acute GVHD. One way to exploit this knowledge could be to individualize the pharmacologic immunosuppression given post transplant. This immunosuppression is given primarily to prevent the development of GVHD but may also inhibit the GVT effect. In patients with a low risk of GVHD early tapering of the immunosuppression could be done, while the period of immunosuppression could be extended in patients with a high risk of GVHD. In this way the GVT effect could theoretically be optimized in each patient and the results of the treatment improved. In another study we used limiting dilution analysis to monitor the frequencies of interleukin (IL)-2 producing helper T cells responding to recipient or donor antigens following the transplant. The conclusion from this study was that both the technical performance and the data analysis were to complex for this method to be used as a routine clinical tool. However, the study showed that immune responses following HCT are subject to a tight regulation and suggested that this regulation could be due to regulatory cell populations. Such regulatory cell populations have been used successfully in animal models to treat acute GVHD. The secretion of cytokines is an important aspect of immune responses. We analyzed cytokine gene expression in mononuclear cells obtained from patients and donors before and after HCT. Patients with acute GVHD had lower levels of IL-10 mRNA on day +14 than patients who did not develop acute GVHD. Patients who experienced progression or relapse of the malignant disease were characterized by higher levels of IL-10 mRNA before the transplant than patients who remained in remission. The conclusion of this study was that IL-10 might be an inhibitor of alloreactivity following allogeneic HCT with nonmyeloablative conditioning. Allogeneic HCT with nonmyeloablative conditioning represents a major step forward in the treatment of patients with hematologic malignancies. However, many issues such as whom to transplant and when the transplant should be performed remain to be clarified. Large prospective studies, involving collaboration between centers, are needed to define the role of HCT with nonmyeloablative conditioning along with other treatment modalities. In addition, it is important to continue to elucidate the immunologic mechanisms that are responsible for GVHD and the GVT effect.

Evidence for involvement of clonally expanded CD8+ T cells in anticancer immune responses in CLL patients following nonmyeloablative conditioning and hematopoietic cell transplantation

We have analyzed the clonotype composition of CD8+ T cells following nonmyeloablative (NMA) conditioning and hematopoietic cell transplantation (HCT), of patients with chronic lymphocytic leukemia (CLL). Consecutive analyses of blood samples taken up to 2 years following HCT, demonstrated that CD8+ T-cell clonality was highly dynamic in the early phases after HCT, but became more stable after 4-5 months. Moreover, donor lymphocyte infusion (DLI) given for disease progression in one of the patients led to establishment of recurrent as well as new T-cell clonotypes. This coincided with disease remission, strongly suggesting that these T cells were engaged with anti-CLL cytotoxicity. To examine the functional capacity of stable clonally expanded T cells after HCT, CD8+ T cells isolated post-transplant from the recipients were stimulated ex vivo with CLL cells and subsequently analyzed by FACS for surface expression of the marker for cytotoxic activity, CD107a. Stimulation with CLL cells indeed led to surface expression of CD107a, and clonotype analyses of sorted cells demonstrated that CD107a positive T cells were stably expanded following HCT. Our data suggest that clonally expanded CD8+ T-cell clones participate in the ongoing T-cell response against CLL cells following HCT with NMA conditioning.

Sex-related differences in the distribution of opioid receptor-like 1 receptor mRNA and colocalization with estrogen receptor mRNA in neurons of the spinal trigeminal nucleus caudalis in the rat

We recently reported that exogenously applied orphanin FQ, the endogenous ligand for opioid receptor-like 1 (ORL(1)) receptor, produces sex-specific modulation of trigeminal nociception, and that estrogen contributes to these sex-related differences. Estrogen could produce these sex-related differences by altering the expression of the ORL(1)-receptor gene in the trigeminal nucleus caudalis. Utilizing in situ hybridization, we compared levels of ORL(1) receptor mRNA and investigated its colocalization with estrogen receptor mRNA in trigeminal neurons. Our results showed that in male rats, ORL(1) receptor mRNA is abundantly expressed in the rostral part of the trigeminal nucleus caudalis, and at the junction of caudalis and interpolaris (Vc/Vi). In comparison with males, levels of ORL(1) receptor mRNA were not significantly different in proestrus females, but were significantly higher in the rostral trigeminal nucleus caudalis and at the junction of Vc/Vi of diestrus females. In addition, ovariectomy raised the levels in the rostral trigeminal nucleus caudalis, and at the junction of Vc/Vi. Levels were reduced to proestrus levels in these regions following estradiol replacement. Our results also showed that ORL(1) receptor mRNA is present in majority of estrogen receptor (alpha and/or beta) mRNA-containing neurons. We conclude that there are sex-related differences in the ORL(1)-receptor gene expression in the trigeminal nucleus caudalis, which appear to be determined in part by estrogen levels.

A comparison of T-, B- and NK-cell reconstitution following conventional or nonmyeloablative conditioning and transplantation with bone marrow or peripheral blood stem cells from human leucocyte antigen identical sibling donors

This retrospective study compares the reconstitution of T, B and NK cells in three groups of patients transplanted for haematological malignancies with grafts from their HLA-identical sibling donors. In all, 15 patients received PBSC after a nonmyeloablative conditioning regimen consisting of fludarabine and 200 cGy TBI, 13 patients received PBSC after myeloablative conditioning and 37 patients received BM after myeloablative conditioning. In the nonmyeloablative group, the NK cells normalised after 1 month, the CD8+ T cells normalised after 3 months, the CD4+ T cells reached near normal values after 9 months and the B cell values were reduced until 12 months after transplant. In the two myeloablative groups, recipients of PBSC had a significantly higher number of CD4+ T cells after 4 months (P=0.004) and after 12 months (P=0.001), than recipients of BM. We found no differences in the T cell reconstitution between the two PBSC groups. This was of interest as the recipients of nonmyeloablative conditioning were older (P<0.001) and had a higher occurrence of chronic GVHD (P<0.05) than the recipients of myeloablative conditioning. In contrast, the recipients of nonmyeloablative conditioning had a delayed B cell recovery when compared to the patients who received myeloablative conditioning (P=0.04).

Oestradiol-dependent and -independent modulation of tyrosine hydroxylase mRNA levels in subpopulations of A1 and A2 neurones with oestrogen receptor (ER)alpha and ER beta gene expression

Oestradiol (E2) induces luteinizing hormone-releasing hormone (LHRH) hypersecretion, thereby triggering LH surge release in ovariectomized (OVX) rats. Neural signals responsible for the surge are marked by a morning increase in LHRH gene expression and an afternoon increase in LHRH release. Evidence suggests that subpopulations of noradrenergic neurones may be responsible for one or both of these signals. To further investigate this issue, we examined effects of E2 on the activity of A1 and A2 noradrenergic neurones, as reflected in changes in tyrosine hydroxylase (TH) mRNA expression, on the day of LH surge release. We then used dual-label in situ hybridization to determine whether E2-induced changes occurred primarily in A1 and A2 subdivisions wherein most noradrenergic neurones expressed oestrogen receptor (ER)alpha and/or ER beta mRNA. We found that in all subdivisions, levels of TH mRNA were higher in E2- than oil-treated rats at 12.00 h. These differences resulted from a decline in TH mRNA expression in oil-treated rats, as well as a rise in levels in E2-treated rats between 10.00 h and 12.00 h. During the afternoon, TH mRNA expression in most A1 and A2 subdivisions peaked at 14.00 h when LH surge release began. However, in all but the middle and caudal A2 subdivisons, levels were similar in E2-treated and control rats at this time. This was attributable to a widespread increase in TH mRNA expression between 12.00 h and 14.00 h in OVX rats. There was no evidence that E2 induced changes in TH mRNA expression preferentially in regions wherein most neurones contained ER alpha or ER beta mRNA. Our findings suggest that E2 activation of middle and caudal A2 neurones, in conjunction with the widespread E2-independent activation of noradrenergic neurones in other subdivisions, may play a role in the induction of LH surge release.

Optimisation of the CT h4S bioassay for detection of human interleukin-4 secreted by mononuclear cells stimulated by phytohaemaglutinin or by human leukocyte antigen mismatched mixed lymphocyte culture

Limiting dilution analysis has been used in the context of allogeneic bone marrow transplantation to determine anti-recipient interleukin-2 (IL-2) producing helper T lymphocyte precursor (HTLp) frequencies, which in several studies have been predictive of graft-versus-host disease (GVHD). Recently high anti-recipient IL-4 producing HTLp frequencies have been reported and associated with a decreased risk of GVHD. The aim of the present study was to define the optimal conditions for combined determination of IL-2 and IL-4 producing anti-recipient HTLp frequencies. We have optimised the CT.h4S bioassay with regards to specificity, sensitivity, detection limit, and reproducibility. We have found the optimal assay conditions to be 1 x 10 (4) CT.h4S cells/well deprived of IL-4 for 24 h and preincubated for 7 h followed by 18 h of incubation with tritiated methyl-thymidine. In this setting the CT.h4S bioassay detects 5 pg/ml of human recombinant IL-4 with no detection of IL-2 in concentrations below 500 pg/ml. We have found 72 h of culture optimal for detection of IL-2 and IL-4 produced by human mononuclear cells (MNC) in response to stimulation with phytohaemaglutinin and for detection of IL-2 in human leukocyte antigen (HLA)-mismatched mixed leukocyte culture (MLC). An interindividual variation in cytokine accumulation was demonstrated for IL-4 but not for IL-2. With the use of 5x10(4) responder cells/well no IL-4 could be detected in HLA-mismatched MLC between days 1 and 16. The lack of IL-4 detection was not due to high amounts of soluble IL-4 receptor. With the use of 1x10(6) responder cells/well in HLA-mismatched MLC, we found limited IL-4 accumulation still increasing at day 12. We conclude that the CT.h4S bioassay is a reliable and specific method for quantification of IL-4 accumulation in cultures of human MNC. The difference in optimal timing for IL-2 (day 3) and IL-4 (>/=day 12) detection and evidence of very low IL-4 producing HTLp frequencies makes the relevance of a combined IL-2/IL-4 HTLp assay questionable.

Regulation of glutamic acid decarboxylase 65 and 67 gene expression by ovarian steroids: identification of two functionally distinct populations of GABA neurones in the preoptic area

GABA neurones in the preoptic area (POA) are critical for oestradiol (E2)-dependent surge release of luteinizing hormone (LH); however, it is not clear which population(s) of POA GABA neurones is involved. The goals of the present studies were: (i) to determine whether E2 regulates GABA neurones similarly in two subdivisions of the POA that play a role in LH surge release, the rostral POA region that contains the organum vasculosum of the lamina terminalis (rPOA/OVLT), and the region containing the anteroventral periventricular nucleus (AVPV) and medial preoptic nucleus (MPN) and (ii) to determine whether GABA neurones in either or both regions exhibit temporal changes consistent with a role in the regulation of LH surge release. To accomplish these goals, we measured glutamic acid decarboxylase (GAD) 65 and 67 mRNA levels at several time points in ovariectomized (OVX), E2-treated OVX rats exhibiting LH surge release, and in E2-treated OVX rats in which LH surge release was blocked by prior administration of progesterone (P4). Our findings demonstrate that, despite their close proximity, GABA neurones in the AVPV/MPN region are regulated differently from those in the rPOA/OVLT. Only neurones in the AVPV/MPN region show temporal changes in GAD 67 mRNA expression that appear to be linked to positive-feedback effects of E2 on luteinizing hormone-releasing hormone (LHRH) and LH release. Our findings also indicate that a morning rise and an afternoon fall in GAD 67 mRNA levels marks two E2-dependent signals required for LHRH and LH surge release. Finally, our results suggest that there are distinct E2-induced signals to the rPOA/OVLT and AVPV/MPN regions and that these signals differentially regulate GAD 65 and 67 gene expression.

Estrogen receptor-beta immunoreactivity in luteinizing hormone-releasing hormone neurons of the rat brain

Feedback regulation of luteinizing hormone-releasing hormone (LHRH) neurons by estradiol plays important roles in the neuroendocrine control of reproduction. Recently, we found that the majority of LHRH neurons in the rat contain estrogen receptor-beta (ER-beta) mRNA, whereas, they seemed to lack ER-alpha mRNA expression. In addition, we observed nuclear uptake of (125)I-estrogen by a subset of these cells. These data suggest that ER-beta is the chief receptor isoform mediating direct estrogen effects upon LHRH neurons. To verify the translation of ER-beta protein within LHRH cells, the present studies applied dual-label immunocytochemistry (ICC) to free-floating sections obtained from the preoptic area of rats. The improved ICC method using the silver-gold intensification of nickel-diaminobenzidine chromogen, enabled the observation of nuclear ER-beta-immunoreactivity in the majority of LHRH cells. The incidence of ER-beta expression was similarly high in LHRH neurons of ovariectomized female (87.8 +/- 2.3%, mean +/- SEM), estradiol-primed female (74.9 +/- 3.2%) and intact male (85.0 +/- 4.7%) rats. The presence of ER-beta mRNA, ER-beta immunoreactivity and (125)I-estrogen binding sites in LHRH neurons of the rat provide strong support for the notion that these cells are directly regulated by estradiol, through ER-beta. The gene targets and molecular mechanisms of this regulation remain unknown.

Autoreactivity, backstimulation and reproducibility in a helper T lymphocyte precursor assay

Helper T lymphocyte precursor (HTLp) frequencies determined by limiting dilution analysis (LDA) have a predictive value for alloreactivity in allogeneic bone marrow transplantation. Methodological problems in LDA include autoreactivity in the responder or stimulator cell populations and interleukin 2 (IL-2) production by the stimulator cells as a response to the responder cells (backstimulation). The extent and impact of these aspects for IL-2 production and HTLp frequency determination were studied by autologous and allogeneic mixed lymphocyte reactions with healthy volunteers and HTLp determinations from bone marrow transplantation donor/recipient pairs. We found that autoreactivity occurred in the unirradiated cells with a reproducible inter-individual variation. The immunogenicity of the stimulator cells was preserved after gamma irradiation with 50 Gy and the risks of autoreactivity and backstimulation were limited. Higher doses of irradiation decreased the immunogenicity. Immune reactions to antigens present in the serum supplement of the culture medium were seen with foetal calf serum and to a lesser extent with pooled human sera. This could be avoided by the use of autologous serum. We were unable to ensure satisfactory culture conditions in serum-free medium. The reproducibility of the HTLp frequency determinations was tested for intra- and inter-assay variation. The coefficients of variation were estimated as 24% and 35%, respectively. This was acceptable considering the range of the HTLp frequencies (1:10(2) to 1:10(7)). The influence of the extent of autoreactivity of the bone marrow donors was investigated in 28 HLA-identical sibling transplantations. We found no correlation between the autoreactivity of the donors and the HTLp frequencies. The extent of autoreactivity of the donor did not correlate with the clinical outcome in terms of acute graft-versus-host disease, treatment-related mortality, risk of relapse and overall survival. In spite of methodological difficulties and interference from autoreactivity and backstimulation, reproducible quantification of clinically significant alloreactivity can be attained.

Distribution of mRNAs encoding the arylhydrocarbon receptor, arylhydrocarbon receptor nuclear translocator, and arylhydrocarbon receptor nuclear translocator-2 in the rat brain and brainstem

Dioxin exposure alters a variety of neural functions, most likely through activation of the arylhydrocarbon receptor (AhR) pathway. Many of the adverse effects, including disruption of circadian changes in hormone release and depressed appetite, seem to be mediated by hypothalamic and/or brainstem neurons. However, it is unclear whether these effects are direct or indirect, because there have been no comprehensive studies mapping the expression of components of the AhR pathway in the brain. Therefore, we used a sensitive in situ hybridization histochemical (ISHH) method to map the neural expression of AhR mRNA, as well as those of the mRNAs encoding the AhR dimerization partners, arylhydrocarbon receptor nuclear translocator (ARNT) and ARNT2. We found that AhR, ARNT, and ARNT2 mRNAs were widely distributed throughout the brain and brainstem. There was no neuroanatomic evidence that AhR is preferentially colocalized with ARNT or ARNT2. However, ARNT2, unlike ARNT expression, was relatively high in most regions. The most noteworthy regions in which we found AhR, ARNT, and ARNT2 mRNA were several hypothalamic and brainstem regions involved in the regulation of appetite and circadian rhythms, functions that are disrupted by dioxin exposure. These regions included the arcuate nucleus (Arc), ventromedial hypothalamus (VMH), paraventricular nucleus (PVN), suprachiasmatic nucleus (SCN), nucleus of the solitary tract (NTS), and the dorsal and median raphe nuclei. This neuroanatomic information provides important clues as to the sites and mechanisms underlying the previously unexplained effects of dioxins in the central nervous system.

Detection of estrogen receptor-beta messenger ribonucleic acid and 125I-estrogen binding sites in luteinizing hormone-releasing hormone neurons of the rat brain

Luteinizing hormone-releasing hormone (LHRH) neurons of the forebrain play a pivotal role in the neuroendocrine control of reproduction. Although serum estrogen levels influence many aspects of LHRH neuronal activity in the female, earlier studies were unable to detect estrogen receptors (ERs) within LHRH neurons, thus shaping a consensus view that the effects of estradiol on the LHRH neuronal system are mediated by interneurons and/or the glial matrix. The present studies used dual-label in situ hybridization histochemistry (ISHH) and combined LHRH-immunocytochemistry/125I-estrogen binding to readdress the estrogen-receptivity of LHRH neurons in the female rat. In ISHH experiments we found that the majority of LHRH neurons exhibited hybridization signal for the "beta" form of ER (ER-beta). The degree of colocalization was similar in topographically distinct populations of LHRH neurons and was not significantly altered by estradiol (67.2+/-1.8% in ovariectomized and 73.8+/-4.2% in ovariectomized and estradiol-treated rats). In contrast, the mRNA encoding the classical ER-alpha could not be detected within LHRH neurons. In addition, in vivo binding studies using 125I-estrogen revealed a subset of LHRH-immunoreactive neurons (8.8%) which accumulated the radioligand thus providing evidence for the translation of ER protein(s) within these cells. The findings that most LHRH neurons in the female rat express ER-beta mRNA and at least some are capable of binding 125I-estrogen challenge the current opinion that estrogen does not exert direct effects upon the LHRH neuronal system.

Co-expression of melatonin (MEL1a) receptor and arginine vasopressin mRNAs in the Siberian hamster suprachiasmatic nucleus

Durational melatonin signals, cued by the photoperiod and generated by the pineal gland, are processed in the brain to induce seasonally appropriate physiological and behavioural adaptations. The melatonin receptor subtype MEL1a (also known as mt1) appears to regulate seasonal responses. Single label in situ hybridization for MEL1a receptor mRNA revealed labelled cells in several brain regions of Siberian hamsters, including the suprachiasmatic nucleus, the paraventricular nucleus of the thalamus, and the reuniens nucleus of the thalamus. To characterize suprachiasmatic nucleus cells containing MEL1a receptor mRNA, we used 35S-labelled cRNA probes for MEL1a receptor mRNA in combination with digoxigenin-labelled cRNA probes for vasopressin, somatostatin, or orphan retinoid Z receptor beta (RZRbeta; a putative nuclear melatonin receptor). Cells in the suprachiasmatic nucleus that contained MEL1a receptor mRNA also contained mRNAs for vasopressin and RZRbeta, but not for somatostatin. These data suggest that suprachiasmatic nucleus vasopressin cells may respond to melatonin signals, raising the possibility that suprachiasmatic nucleus vasopressin output mediates some of the effects of melatonin on seasonal or circadian responses.

Cerebral and meningeal multiple myeloma after autologous stem cell transplantation. A case report and review of the literature

Meningeal involvement of multiple myeloma is a very rare complication. Defining meningeal myelomatosis (MeM) as the presence of plasma cells in the cerebrospinal fluid in a patient with multiple myeloma, we have found 53 previously reported cases in the literature, where the diagnosis MeM has been made while the patient was alive. Using Kaplan Meier statistics we have found the median survival, from the time of diagnosis of MeM, to be 1.5 months. We report a case with MeM and possible cerebral myeloma shortly after autologous stem cell transplantation, and compare it with earlier published cases.

Prostate gland growth during development is stimulated in both male and female rat fetuses by intrauterine proximity to female fetuses

In rodents, steroid hormones are transported between adjacent fetuses, and male or female fetuses that develop in utero between female fetuses (2F males or 2F females) have higher serum levels of estradiol and lower serum levels of testosterone relative to siblings of the same sex that develop between two male fetuses (2M males or 2M females). The present study was prompted by the prior unexpected finding that as adults, 2F male mice have an enlarged prostate, and increased numbers of prostatic androgen receptors relative to 2M males. We examined prostate development in both male and female rat fetuses from different intrauterine positions using computer-assisted, 3-dimensional reconstruction of the urogenital complex. In males, this included the prostate, seminal vesicles and utricle (a remnant of the Müllerian ducts), while in females it included development of prostatic glandular buds. The mean cross-sectional area of developing prostatic epithelial buds, utricle and seminal vesicles was significantly increased in 2F male relative to 2M male fetuses. In female fetuses, prostatic bud development was significantly more likely to occur in 2F (67%) than in 2M (29%) animals. These findings suggest that the transport of a small supplement of estrogen from adjacent female fetuses enhances androgen-dependent accessory organ development. We also found that mRNAs encoding receptors for both estrogen and androgen were located in the mesenchyme of the developing male prostate. The localization of estrogen and androgen receptor mRNA in this region further suggests that the mesenchymal induction of prostatic epithelial growth involves both hormones. The cranial dorsolateral prostatic buds exhibited the greatest enlargement in 2F males. This region of the developing prostate in rats is comparable (that is the embryonic homologue) to the region exhibiting benign prostatic hyperplasia (BPH) during aging in men. We propose that the potential for pathological regrowth of the prostate during aging is imprinted by estradiol during fetal development.

The effect of low level laser therapy (LLLT) on wound healing in horses

Laser therapy is used in many countries, including South Africa, for the treatment of skin wounds. Low level galium aluminium arsenide (GaAlAs) laser was administered to full thickness skin wounds (3 x 3 cm) induced surgically on the dorsal aspect of the metacarpophalangeal joints of 6 crossbred horses in a randomised, blind, controlled study. Treated wounds that received a daily laser dosage of 2 J/cm2 were compared with nontreated control wounds on the opposite leg. There were no wound complications. Both groups of wounds were cleaned daily using tap water. Wound contraction and epithelialisation were evaluated using photoplanimetry. There were no significant differences in wound contraction or epithelialisation between the laser treated and the control wounds. It was therefore concluded that laser therapy had no clinically significant effect on second intention wound healing in this study.