Aymen Bushra Ahmed

Extracorporeal photopheresis (photochemotherapy) in the treatment of acute and chronic graft versus host disease: immunological mechanisms and the results from clinical studies

Abstract Extracorporeal photopheresis (ECP) is an immunomodulatory alternative for treatment of graft versus host disease (GVHD). The blood is then separated into its various components through apheresis; buffy coat cells are thereafter treated with 8-methoxypsoralen before exposure to ultraviolet light and finally reinfused into the patient. There is a general agreement that this treatment has an anti-GVHD effect, but the mechanisms of action behind this effect are only partly understood. However, altered maturation of dendritic cells (DC) and thereby indirect modulation of T-cell reactivity seems to be one important mechanism together with DC-presentation of antigens derived from apoptotic donor T cells and induction of regulatory T cells. The treatment has been best studied in patients with chronic GVHD (both pediatric and adult patients), but most studies are not randomized and it is difficult to know whether the treatment is more effective than the alternatives. The clinical studies of ECP in adults with acute GVHD are few and not randomized; it is not possible to judge whether this treatment should be a preferred second- or third-line treatment. There is no evidence for increased risk of leukemia relapse or suppression of specific graft versus leukemia reactivity by this treatment, so specific antileukemic immunotherapy may still be possible. Thus, even though the treatment seems effective in patients with GVHD, further clinical (especially randomized) as well as biological studies with careful standardization of the treatment are needed before it is possible to conclude how ECP should be used in acute and chronic GVHD.

Targeting of polo-like kinases and their cross talk with Aurora kinases – possible therapeutic strategies in human acute myeloid leukemia?

Introduction: Five human polo-like kinases (PLKs) have been identified, and PLK1 – 4 seem to interact with Aurora kinases and act as cell cycle regulators in both normal and malignant human cells. Areas covered: The present review describes i) experimental evidence for a role for PLKs and Aurora kinases in human leukemogenesis and ii) the results from clinical studies of PLK and Aurora kinase inhibitors in the treatment of human acute myeloid leukemia (AML). The review was based on searches in the PubMed and the ClinicalTrials.gov databases. These inhibitors have antiproliferative and proapoptotic effects in AML cells. Hematological and gastrointestinal toxicities are frequently dose limiting, and this may limit the use of these agents in combination with conventional AML therapy. Aurora kinase inhibitors seem to be most effective for patients with high expression of the target kinases, and the same may be true for PLK inhibitors. Expert opinion: PLK inhibition is a promising strategy for the treatment of AML. Future clinical studies have to clarify i) whether this strategy is most effective for certain subsets of patients; ii) whether multikinase inhibitors targeting several cell cycle regulators should be preferred; and iii) how this therapeutic strategy eventually should be combined with conventional antileukemic chemotherapy.

Strain measurement during antral contractions by ultrasound strain rate imaging: influence of erythromycin.

Abstract  Strain rate imaging (SRI) is a non‐invasive ultrasound (US) modality that enables the study of mechanical deformation (strain) with high spatial and temporal resolution. A total of 244 contractions in seven healthy volunteers were studied by SRI on two separate days to characterize radial strain of antral contractions in the fasting and fed states and to assess the influence of intravenous erythromycin. Gastric accommodation and emptying were assessed by 2D ultrasonography. The perception of hunger was registered by the participants. The strain increased from early to late phase II and phase III activity by (median) 18%, 58% and 82%, respectively, P < 0.05. Erythromycin infusion in phase I induced contractions with median strain of 35%, but did not increase postprandial strain. Both fasting and postprandially, lumen‐occlusive contractions with erythromycin were more frequent than in naturally occurring contractions, 69%vs 48%, P = 0.036 and 40%vs 5%, P < 0.001 respectively. All subjects had rumbling in their abdomens when intraluminal air was detected sonographically (85% of all phase III contractions) and that rumbling was perceived by the participant as maximal awareness of hunger. SRI enabled detailed strain measurement of individual antral contractions. Erythromycin initiated fasting antral contractions and increased the number of lumen‐occlusive contractions.

Rome III subgroups of functional dyspepsia exhibit different characteristics of antral contractions measured by strain rate imaging - a pilot study.

PURPOSE Rome III defines two distinct entities of functional dyspepsia (FD), namely epigastric pain syndrome (EPS) and postprandial distress syndrome (PDS). We aimed at studying these subgroups of FD by simultaneously assessing antral strain, gastric accommodation and emptying and visceral hypersensitivity. MATERIALS AND METHODS Strain during antral contractions was assessed by ultrasound strain rate imaging in 15 controls and 19 FD patients (8 EPS patients and 11 PDS patients). Gastric accommodation and emptying were assessed using B-mode ultrasonography. Symptoms were assessed by visual analogue scale (VAS). RESULTS During fasting, antral strain in EPS patients (mean±SEM) was 61.4 ± 6.4 %, significantly higher than in controls (47.5 ± 3.3 %; p = 0.042) and in PDS patients (28.6 ± 1.7 %; p = 0.001). PDS patients had lower strain than controls (p < 0.001). Postprandially, EPS patients had higher strain than both controls and PDS patients (p < 0.01) but no difference was found between controls and PDS patients. Compared with controls, PDS patients had significantly larger fasting proximal area than controls (14.9 ± 1.6 cm2 vs. 7.8 ± 0.2 cm2; p < 0.001), whereas EPS patients did not differ (12.1 ± 1.9 cm2; p = 0.057). Gastric emptying fraction (1 - proximal area at 40 min postprandially/area at 1 min postprandial × 100) at 40 min postprandially in EPS patients 46.4 ± 6.6 % was lower than in controls (62.9 ± 1.3 %; p = 0.032), but higher than PDS patients (27.4 ± 5.3 %; p = 0.018). CONCLUSION Anterior radial strain measured by ultrasound strain rate imaging may discriminate between subgroups of FD and healthy controls. This study supports the Rome III classification of FD into EPS and PDS groups.

Pretransplant Levels of CRP and Interleukin-6 Family Cytokines; Effects on Outcome after Allogeneic Stem Cell Transplantation

Several pretransplant factors, including CRP (C-reactive protein) levels, reflect the risk of complications after allogeneic stem cell transplantation. IL-6 induces CRP increase, and we therefore investigated the effects of pretransplant IL-6, soluble IL-6 receptors, IL-6 family cytokines and CRP serum levels on outcome for 100 consecutive allotransplant recipients. All patients had related donors, none had active infections and 99 patients were in complete remission before conditioning. The incidence of acute graft versus host disease (aGVHD) requiring treatment was 40%, survival at Day +100 82%, and overall survival 48%. Despite a significant correlation between pretransplant CRP and IL-6 levels, only CRP levels significantly influenced transplant-related mortality (TRM). However, CRP did not influence overall survival (OS). Pretransplant IL-31 influenced late TRM. Finally, there was a significant association between pretransplant IL-6 and early postconditioning weight gain (i.e., fluid retention), and this fluid retention was a risk factor for aGVHD, TRM and OS. To conclude, pretransplant CRP, IL-31 and early posttransplant fluid retention were independent risk factors for TRM and survival after allotransplantation.

Metabolic Serum Profiles for Patients Receiving Allogeneic Stem Cell Transplantation: The Pretransplant Profile Differs for Patients with and without Posttransplant Capillary Leak Syndrome.

Allogeneic stem cell transplantation is commonly used in the treatment of younger patients with severe hematological diseases, and endothelial cells seem to be important for the development of several posttransplant complications. Capillary leak syndrome is a common early posttransplant complication where endothelial cell dysfunction probably contributes to the pathogenesis. In the present study we investigated whether the pretreatment serum metabolic profile reflects a risk of posttransplant capillary leak syndrome. We investigated the pretransplant serum levels of 766 metabolites for 80 consecutive allotransplant recipients. Patients with later capillary leak syndrome showed increased pretherapy levels of metabolites associated with endothelial dysfunction (homocitrulline, adenosine) altered renal regulation of fluid and/or electrolyte balance (betaine, methoxytyramine, and taurine) and altered vascular function (cytidine, adenosine, and methoxytyramine). Additional bioinformatical analyses showed that capillary leak syndrome was also associated with altered purine/pyrimidine metabolism (i.e., metabolites involved in vascular regulation and endothelial functions), aminoglycosylation (possibly important for endothelial cell functions), and eicosanoid metabolism (also involved in vascular regulation). Our observations are consistent with the hypothesis that the pretransplant metabolic status can be a marker for posttransplant abnormal fluid and/or electrolyte balance.

The healthy donor profile of immunoregulatory soluble mediators is altered by stem cell mobilization and apheresis

BACKGROUND Peripheral blood stem cells from healthy donors mobilized by granulocyte colony-stimulating factor (G-CSF) and thereafter harvested by leukapheresis are commonly used for allogeneic stem cell transplantation. METHODS Plasma levels of 38 soluble mediators (cytokines, soluble adhesion molecules, proteases, protease inhibitors) were analyzed in samples derived from healthy stem cell donors before G-CSF treatment and after 4 days, both immediately before and after leukapheresis. RESULTS Donors could be classified into two main subsets based on their plasma mediator profile before G-CSF treatment. Seventeen of 36 detectable mediators were significantly altered by G-CSF; generally an increase in mediator levels was seen, including pro-inflammatory cytokines, soluble adhesion molecules and proteases. Several leukocyte- and platelet-released mediators were increased during apheresis. Both plasma and graft mediator profiles were thus altered and showed correlations to graft concentrations of leukocytes and platelets; these concentrations were influenced by the apheresis device used. Finally, the mediator profile of the allotransplant recipients was altered by graft infusion, and based on their day +1 post-transplantation plasma profile our recipients could be divided into two major subsets that differed in overall survival. DISCUSSION G-CSF alters the short-term plasma mediator profile of healthy stem cell donors. These effects together with the leukocyte and platelet levels in the graft determine the mediator profile of the stem cell grafts. Graft infusion also alters the systemic mediator profile of the recipients, but further studies are required to clarify whether such graft-induced alterations have a prognostic impact.

Bronchiolitis obliterans syndrome in adults after allogeneic stem cell transplantation-pathophysiology, diagnostics and treatment.

ABSTRACT Introduction: Transplant-related complications are common after allogeneic hematopoietic stem cell transplantation (allo-HSCT), including graft versus host disease (GVHD). The lungs are frequently affected during the course of allo-HSCT, and among the non-infectious pulmonary complications bronchiolitis obliterans syndrome (BOS) is the most common and considered the only diagnostic manifestation of pulmonary GVHD. BOS is an irreversible obstructive disease that affects the terminal bronchioles, and it is associated with high morbidity and mortality rates. Area covered: We discuss the features of chronic GVHD, including the pathophysiological and cytokine-mediated alteration in BOS. Early treatment, before structural and irreversible changes have occurred, is crucial to reduce disease morbidity and mortality. This is challenging, given the unspecific symptoms of early stage disease and the complexity of the disease pathophysiology, obstructing both the diagnostic workup and the initiation of treatment. We highlight the main issues regarding diagnostic challenges, and we discuss the treatment options with a focus on new therapeutic options and modalities. Expert commentary: BOS is one of the most serious late complications after allo-HSCT and remains a diagnostic and therapeutic challenge. Thus, new and more effective therapeutic alternatives are strongly warranted.

Novel variants in Nordic patients referred for genetic testing of telomere-related disorders

Telomere-related disorders are a clinically and genetically heterogeneous group of disorders characterized by premature telomere shortening and proliferative failure of a variety of tissues. This study reports the spectrum of telomere-related gene variants and telomere length in Nordic patients referred for genetic testing due to suspected telomere-related disorder. We performed Sanger sequencing of the genes TERT, TERC, DKC1, and TINF2 on 135 unrelated index patients and measured telomere length by qPCR on DNA from peripheral blood leukocytes. We identified pathogenic or likely pathogenic variants in 10 index patients, all of which had short telomeres compared to age-matched healthy controls. Six of the 10 variants were novel; three in TERC (n.69_74dupAGGCGC, n.122_125delGCGG, and n.407_408delinsAA) and three in TERT (p.(D684G), p.(R774*), and p.(*1133Wext*39)). The high proportion of novel variants identified in our study highlights the need for solid interpretation of new variants that may be detected. Measurement of telomere length is a useful approach for evaluating pathogenicity of genetic variants associated with telomere-related disorders.

A pilot study of single nucleotide polymorphisms in the interleukin-6 receptor and their effects on pre- and post-transplant serum mediator level and outcome after allogeneic stem cell transplantation: SNPs in the IL-6R and allotransplantation

Interleukin (IL)‐6 is an important regulator of immunity and inflammation in many diseases. Single nucleotide polymorphisms (SNPs) in the IL‐6 gene influence outcome after allogeneic stem cell transplantation (ASCT), but the possible importance of SNPs in the IL‐6 receptor has not been examined. We therefore investigated whether SNPs in the IL‐6R gene influenced biochemical characteristics and clinical outcomes after ASCT. We examined the IL‐6 promoter variant rs1800975 and the IL‐6R SNPs rs4453032, rs2228145, rs4129267, rs4845374, rs4329505, rs4845617, rs12083537, rs4845618, rs6698040 and rs4379670 in a 101 population‐based cohort of allotransplant recipients and their family donors. Patients being homozygous for the major alleles of the IL‐6R SNPs rs2228145 and rs4845618 showed high pretransplant CRP serum levels together with decreased sIL‐6R levels; the decreased IL‐6R levels persisted 6 months post‐transplant. In contrast, patients being homozygous for the minor allele of the IL‐6R SNP rs4379670 showed decreased pretransplant CRP levels. Furthermore, the IL‐6R rs4845618 donor genotype showed an association with severe acute graft‐versus‐host disease (GVHD), whereas the donor genotype of the IL‐6 SNP rs1800795 was associated with decreased survival 100 days post‐transplant. Finally, the recipient genotype of the IL‐6R SNP rs4329505 showed a strong association with 2‐years non‐relapse mortality, and this effect was also highly significant in multivariate analysis. IL‐6 and IL‐6R SNPs influence the clinical outcome after allogeneic stem cell transplantation.