Cutaneous leukocytoclastic vasculitis: the role of lymphocytes and related immune markers.

INTRODUCTION: Apart from neutrophils, other immune cells may play a significant pathogenetic role in cutaneous leukocytoclastic vasculitis (CLV). AIM: To investigate lymphocytes and related immunological factors in patients with CLV requiring systemic glucocorticosteroid treatment. MATERIAL AND METHODS: Fourteen patients with severe idiopathic CLV were treated with systemic prednisolone in a tapered dose regimen. Ten healthy individuals served as controls. At baseline and post-treatment, we studied inducer/helper and suppressor/cytotoxic T lymphocytes, B lymphocytes, natural killer cells, CD4+CD25++CD127- cells, CD4+CD25+CD39+ cells and FOXP3, transforming growth factor ß1 (TGF-ß1) and interleukin-10 (IL-10) mRNA levels in the blood using flow cytometry and real time polymerase chain reaction (RT-PCR), respectively. On immunohistochemistry, we studied CD4, CD8, granzyme B, TGF-ß1, and IL-10. RESULTS: Flow cytometry did not show significant differences. The RT-PCR revealed that TGF-ß1 mRNA expression was significantly higher after therapy when compared to baseline and controls. On immunohistology, baseline CLV lesions showed significantly more CD4+ lymphocytes than post-treated CLV and controls. CD8+ expression was significantly higher after therapy when compared to baseline and controls. Baseline granzyme B was significantly increased when compared to treated CLV and controls. The IL-10 expression of treated CLV was significantly increased when compared to baseline CLV and; baseline CLV IL-10 expression was significantly increased as compared to controls. CONCLUSIONS: Circulating T regulatory cells do not play a significant role in the pathogenesis of CLV. T helper cells and granzyme B seem to be involved in the inflammatory cutaneous process of CLV. A resolution of CLV observed after glucocorticosteroid treatment may be mediated via up-regulation of TGF-ß1 and IL-10 in different compartments.

[Fulminant Course of a Clostridium Perfringens Infection with Pathognomonic CT finding]. / Fulminanter Verlauf einer Infektion mit Clostridium perfringens mit pathognomischem CT-Befund.

History and clinical findings A 74-year old woman was accepted by the emergency room with severe chest and abdominal pain. She complained about regurgitation after ingestion of food followed by sharp pain in her breast. Investigations A first examination of the patient showed a tachypnoea und tachycardia up to 122 beats per minute, the body temperature measured on admission was 38.7 °C. Due to hemolysis only a few of the requested parameters could be evaluated. CRP was increased with 8.32 mg/dl. The hemoglobin dropped from 12.0 g/dl to 10.3 g/dl during 4 hours. A computed tomography scan was done because of severe worsening of the patient's condition. The CT scan showed two cavities in the right lobe of the liver filled with gas. Treatment and course Initial antibiotic therapy with Ceftriaxon was immediately started. During her stay in the emergency room the patient showed a severe worsening of her condition. Therefore a CT scan was initiated after the abdominal ultrasound revealed nothing specific. During the CT examination the patient stopped breathing sufficiently, followed by hematuria and vomiting a large amount of blood. The patient died 8.5 hours of an irreversible cardiovascular failure after admission to the hospital. Conclusion A rapid decline of the patient's condition in addition to hemolysis and a gas-filled liver necrosis are pathognomonic signs for an infection with clostridium perfringens which requires immediate treatment. Only an immediate surgical intervention in combination with an adapted antibiotic increases chances of survival in patients with clostridia.

Suv39h histone methyltransferases interact with Smads and cooperate in BMP-induced repression.

Smad proteins transduce signals from transforming growth factor-beta (TGF-beta) superfamily ligands to regulate the expression of target genes. In order to identify novel partners of Smad proteins in transcriptional regulation, we performed a two-hybrid screen using Smad5, a protein that is activated predominantly by bone morphogenetic protein (BMP) signaling. We identified an interaction between Smad5 and suppressor of variegation 3-9 homolog 2 (Suv39h2), a chromatin modifier enzyme. Suv39h proteins are histone methyltransferases that methylate histone H3 on lysine 9, resulting in transcriptional repression or silencing of target genes. Biochemical studies in mammalian cells demonstrated that Smad5 binds to both known mammalian isoforms of Suv39h proteins, and that Smad proteins activated by the TGF-beta signaling pathway, Smad2 and Smad3, do not bind with significant affinity. Functional studies using the muscle creatine kinase (MCK) promoter, which is suppressed by BMP signaling, demonstrate that Suv39h proteins and Smads cooperate to repress promoter activity. These data suggest a model where association of Smad proteins with Suv39h methyltransferases can repress or silence genes involved in developmental processes, and argues that inefficient gene repression may result in the alteration of the differentiated phenotype. Thus, examination of the Smad-Suv interaction may provide insight into the mechanism of phenotypic determination mediated by BMP signaling.

Smad proteins regulate transcriptional induction of the SM22alpha gene by TGF-beta.

Smad proteins transduce signals from transforming growth factor-beta (TGF-beta) receptors and regulate transcription of target genes. TGF-beta is implicated in the regulation of the smooth muscle cell specific gene SM22alpha, but little is known about how Smads are involved in SM22alpha gene transcription. In this report, we demonstrate that TGF-beta activation of the SM22alpha promoter is Smad dependent in C3H10T1/2 cells, BALB 3T3 cells and neural crest Monc-1 cells. We find that the promoter region from -162 to +41 is sufficient to up-regulate the reporter gene upon TGF-beta induction. Smad3, Smad1 and Smad4 are found in TGF-beta inducible complexes that bind to a region containing a Smad binding site (SBS) and a medea box. Both the SBS and medea box are necessary for complex formation and are functionally important. Smad4 is limiting for TGF-beta induction, and Smad3, but not Smad1, significantly contributes to maximal activation. Time course luciferase assays and time course gel mobility shift assays reveal that the Smad3/4 complex is largely responsible for the immediate response of the SM22alpha promoter to TGF-beta induction, and also contributes to the maximal promoter activity. We further demonstrate that AP-1 elements contribute to induction of the SM22alpha promoter by TGF-beta.

Disruption of acvrl1 increases endothelial cell number in zebrafish cranial vessels.

The zebrafish mutant violet beauregarde (vbg) can be identified at two days post-fertilization by an abnormal circulation pattern in which most blood cells flow through a limited number of dilated cranial vessels and fail to perfuse the trunk and tail. This phenotype cannot be explained by caudal vessel abnormalities or by a defect in cranial vessel patterning, but instead stems from an increase in endothelial cell number in specific cranial vessels. We show that vbg encodes activin receptor-like kinase 1 (Acvrl1; also known as Alk1), a TGFbeta type I receptor that is expressed predominantly in the endothelium of the vessels that become dilated in vbg mutants. Thus, vbg provides a model for the human autosomal dominant disorder, hereditary hemorrhagic telangiectasia type 2, in which disruption of ACVRL1 causes vessel malformations that may result in hemorrhage or stroke. Movies available on-line