Microcirculatory assessment of vascular diseases.

The term "microcirculation" refers to the terminal vascular network of the body, which includes arterioles, capillaries, venules as well as initial lymphatic vessels. Additionally, it insinuates to their unique function in thermoregulation, fluid balance, maintenance of cellular exchange, and metabolism. Disturbances of microvascular function were identified to precede macrovascular involvement in the presence of cardiovascular risk factors and is the hallmark of terminal disease stages like critical limb or acral ischemia. Nevertheless, despite its obvious significance in vascular medicine assessment of microvascular function became increasingly neglected in the clinical institutions during the last decades and seems to play a subordinary role in medical education. We therefore provide an overview over relevant and clinically practicable methods to assess microcirculation in vascular medicine with critical estimations of their pros and cons and their perspectives in the future.

Thromboangiitis obliterans (Buerger's disease).

Thromboangiitis obliterans (TAO, Buerger's disease) is an inflammatory vascular disease affecting small and medium sized arteries and veins. It is characterized by segmental thrombotic occlusions by highly mononuclear cellular thrombi. Its occurrence and re-occurrence is closely related to tobacco use. Immunohistological examinations and the detections of various autoantibodies led to the new paradigm of an immunopathogenesis of TAO. Clinically it is characterized by distal ischemia syndromes in young people and high amputation rates. This article summarizes the disease characteristics, clinical features, and diagnostic and therapeutic approaches and focuses on new therapeutic options, i.e. stem cell derived therapies, immunoadsorption, and the endothelin-receptor-blocking agent bosentan.

G-protein coupled receptor auto-antibodies in thromboangiitis obliterans (Buerger's disease) and their removal by immunoadsorption.

BACKGROUND: Immunhistopathological and serological data favors an immunopathogenesis of thromboangiitis onliterans (TAO, Buerger's disease). Auto antbodies seem to play a major role. Immunoadsorption (IA) proved to be therapeutically effective. We focused on agonistic autoantibodies (agAAB) directed against G-protein coupled receptors (GPCR) and proved the hypothesis, that these agAAB might be present in TAO and that a five day course of IA might be able to eliminate these agAAB effectively. PATIENTS AND METHODS: Between December 2012 and May 2014 11 TAO-patients were treated by IA in a five day course. AgAAB-analysis was performed using specific ELISA techniques. RESULTS: AgAAB were detected in 9 out of 11 patients (81.8 %).Multiple agAAB were present in 7 patients (63.6 %). A clustering of agAAB directed against loop1 of the adrenergic α1-receptor and the endothelin-A-(ETA)receptor was identified, representing 72.7 % resp. 54.5 % of the patients. AgAAB directed against the angiotensin-1 (AT-1) epitope 1 or 2 were detected in 3 patients and agAAB directed against protease-activated receptor (PAR) loop1/2 were seen in 2 patients. AgAAB directed against ETA-receptor loop1 never appeared without agAAB directed against α1-receptor loop1. Immediately after a five day-course of IA agAAB were absent in 81.8 % of the total study group and in 77.8 % of all cases tested positive for agAAB before IA. CONCLUSIONS: AgAAB directed against GPCR were identified in TAO patients with a clustering of agAAB directed against α-1-adrenergic receptor loop1 and ETA-receptor loop1. AgAA were eliminated by IA in the majority of cases. We suggest that these agAA play an important role in the pathogenesis of TAO and that their elimination might be responsible for the positive therapeutic effects reported in patients treated with IA.