Extracorporeal photopheresis in 62 patients with acute and chronic GVHD: results of treatment with the COBE Spectra System.

In this retrospective analysis, 30 patients with acute GVHD (aGVHD) and 32 patients with chronic GVHD (cGVHD) treated with extracorporeal photopheresis (ECP) performed by the COBE Spectra System were evaluated. After 3 months of ECP treatment, a CR and PR were observed in 9 (30%) and 6 (20%) patients with aGVHD and in 2 (6%) and 12 (38%) patients with cGVHD. In 16 (53%) patients with aGVHD and 9 (28%) with cGVHD ECP treatment was already stopped after 3 months. One (3%) patient with aGVHD and 7 (22%) patients with cGVHD received new additional immunosuppressive therapy started during the first 3 months of ECP treatment and were classified as 'nonresponder' with regard to ECP. Of these patients a PR was achieved in one patient with aGVHD and in three patients with cGVHD. Steroids could be tapered by 50 in 83% of patients with aGVHD and in 29% of patients with cGVHD after 3 months of ECP treatment. Patients with aGVHD achieving a CR or PR showed a significant improved OS after allo-SCT (P=0.019). ECP is associated with significant response rates and successful reduction of steroids in patients with GVHD.

Transmural penetration of intravenously applied microbubbles during contrast-enhanced ultrasound as a new diagnostic feature in patients with GVHD of the bowel.

GVHD is a common complication in patients after allo-SCT. Early detection is important because early therapy may improve the outcome. We evaluated contrast-enhanced ultrasound (CEUS) in patients with GVHD to assess typical imaging features. CEUS was performed in nine patients with histologically proven GVHD. As a control four healthy volunteers and six patients with Crohn's disease (CD) were examined. We employed a high-resolution multi-frequency transducer (6-9 MHz) with contrast harmonic imaging. After the injection of 2.4 mL SonoVue (Bracco, Milan, Italy) intravenously data were acquired and stored digitally. Regions of interest were manually placed over the surrounding mesenteric fat, bowel wall and bowel lumen. Maximum signal increase of each compartment was calculated. Patients with CD and GVHD showed significant contrast uptake in the bowel wall. In contrast to CD patients and healthy volunteers, patients with GVHD showed transmural penetration of microbubbles into the bowel lumen. We assume that the damaged gut mucosal barrier in GVHD enables the microbubbles to penetrate through the bowel wall into the bowel lumen. The penetration of microbubbles into the bowel lumen may serve as a novel diagnostic feature for GVHD if confirmed in controlled clinical trials.

Contrast-enhanced ultrasound for differential diagnosis of suspected GvHD in patients after allogeneic transplantation.

GvHD is a serious complication in patients after allo-SCT, presenting with unspecific symptoms such as abdominal pain or cramps and diarrhea. Early diagnosis of GvHD, after differentiation from other causes leading to the same symptoms, such as viral or bacterial enteritis, is highly important because the time needed for diagnosing GvHD is directly correlated to a worsening of the outcome. We examined 23 patients presenting with the abdominal symptoms mentioned above, of whom 20 had received an allo-SCT in their history and were thus potential candidates for enteric GvHD. The other three patients were included because they also presented with abdominal symptoms similar to those of GvHD, which could be ruled out due to their history. We wanted to evaluate CEUS in these patients as an additional subgroup to gain more data on the value of CEUS in early detection of enteral GvHD and in the differentiation of GvHD against other causes of abdominal discomfort. All patients underwent CEUS with particular attention to penetration of the intravenously applied microbubbles in the bowel lumen. In the patients having allo-SCT in their history we strove to achieve histological confirmation of GvHD of the GI-tract. The resulting examinations were documented digitally. Out of 17 patients with confirmed GvHD of the GI tract, 14 showed penetration of the intravenously applied microbubbles into the bowel lumen, leading to a sensitivity and specificity of 82% and 100% for transmural bubble penetration for GvHD of the GI-Tract, since the patients without GvHD of the GI tract showed no transmural bubble penetration. In patients with viral or bacterial infections of the GI tract, no transmural penetration of the microbubbles into the bowel lumen was observed. For microbubble penetration as a criterion for GvHD of the GI-Tract, this leads to a negative predictive value (NPV) of 67%, and a positive predicative value (PPV) of 100%.

The role of bacteria and pattern recognition receptors in GVHD.

Graft-versus-Host Disease (GvHD) is the most serious complication of allogeneic stem cell transplantation (SCT) and results from an activation of donor lymphocytes by recipient antigen-presenting cells (APCs). For a long time, it has been postulated that the intestinal microflora and endotoxin exert a crucial step in this APC activation, as there is early and severe gastrointestinal damage induced by pretransplant conditioning. With the detailed description of pathogen-associated molecular patterns and pathogen recognition receptors single nucleotide polymorphisms of TLRs and especially NOD2 have been identified as potential risk factors of GvHD and transplant related complications thus further supporting the crucial role of innate immunity in SCT, related complications. Gastrointestinal decontamination and neutralization of endotoxin have been used to interfere with this early axis of activation with some success but more specific approaches of modulation of innate immunity are needed for further improvement of clinical outcome.

Recipient NOD2/CARD15 status affects cellular infiltrates in human intestinal graft-versus-host disease.

Nucleotide-binding oligomerization domain 2/caspase recruitment domain 15 (NOD2/CARD15) polymorphisms have been identified as risk factors of both Crohn's disease and graft-versus-host disease (GVHD) following allogeneic stem cell transplantation. However, the role of these receptors of innate immunity in the pathophysiology of gastrointestinal GVHD is still poorly defined. Immunohistological features of intestinal GVHD were analysed in gastrointestinal biopsies from 58 patients obtained at the time of first onset of intestinal symptoms. The observed changes were correlated with concomitant risk factors and the presence of polymorphisms within the pathogen recognition receptor gene NOD2/CARD15. Intestinal GVHD was associated with a stage-dependent decrease in CD4 T cell infiltrates and an increase in CD8 T cells in the lamina propria; CD8 infiltrates correlated with extent of apoptosis and consecutive epithelial proliferation. The presence of NOD2/CARD15 variants in the recipient was associated with a significant loss of CD4 T cells: in a semiquantitative analysis, the median CD4 score for patients with wild-type NOD2/CARD15 was 1.1 (range 3), but only 0.4 (range 2) for patients with variants (P = 0.002). This observation was independent from severity of GVHD in multivariate analyses and could not be explained by the loss of forkhead box P3(+) T cells. Our results suggest a loss of protective CD4 T cells in intestinal GVHD which is enhanced further by the presence of NOD2/CARD15 variants. Our study might help to identify more selective therapeutic strategies in the future.

Studies on the membrane glycoprotein defect of En(a-) erythrocytes. I. Biochemical aspects.

Discontinuous sodium dodecylsulphate-polyacrylamide gel electrophoresis, followed by periodic acid/Schiff or Coomassie staining and densitometry, spectrophotometric and gas-liquid chromatographic carbohydrate analyses as well as heterophile agglutinins are employed to study the nature of the membrane glycoprotein defect in En(a-) erythrocytes from Finland and England, heterozygous Ena red cells from Finland and the erythrocytes of two individuals from Switzerland. The results suggest that En(a-) cells lack the major membrane sialoglycoprotein, the so-called MN glycoprotein. Heterozygous Ena erythrocytes from Finland and those from Switzerland have only about half of the normal amount of MN glycoprotein. The molecular weight of the major Coomassie staining membrane protein (component III) is increased by approx. 5000 and 3000 daltons in En(a-) and the other red cells respectively. Some aspects of this membrane defect are discussed.