Impaired endothelial-dependent and endothelium-independent vasodilatation in patients with thromboangiitis obliterans

Buerger's Disease May be a Chronic Rickettsial Infection with Superimposed Thrombosis: Literature Review and Efficacy of Doxycycline in Three Patients

Buerger's disease (BD) is a chronic inflammatory vasculitis of unknown etiology. The infectious etiology of BD was proposed by Buerger in 1914. Furthermore, there are scattered reports insisting that BD may be related to rickettsial infection, first asserted by Goodman since 1916, followed by Giroud and other French investigators from the 1940s through the 1960s, Nicolau in the 1960s, Bartolo (1980s), and Fazeli (2010s). However, their causal relationship has hardly been accepted because rickettsial infections are known to be acute febrile, vector-borne illnesses, whereas BD is a chronic afebrile illness. In this article we review the relevant literature on the chronic nature of Rickettsia and Orientia infections and on the rickettsial etiology of BD. Excellent initial responses to doxycycline in three patients with BD are briefly described. Based on these findings, we hypothesize that BD patients acquired a rickettsial infection far before the onset of BD. Over years, the infected area expands to become a segment of the infected vessel. Subsequently, thrombus develops on the luminal surface of the infected endothelial cells, which produces the vascular obstructive manifestations of BD. Collectively, it is postulated that BD is a chronic infection with a member of the family Rickettsiaceae with superimposed thrombosis.

Application of nanofat grafting to rescue a severe ischaemic hand with thromboangiitis obliterans: A case report about promising salvage procedure

RATIONALE

Currently, there is no consensus regarding the best treatment for patients with thromboangiitis obliterans (TAO). Regenerative medicine, such as bone marrow stem cells or adipose-derived stem cell (ASC) transplantation, have proven efficacy in improving tissue perfusion and wound healing in clinical trials. In this case, we used nanofat grafting to treat severe conditions in a patient with TAO, with promising outcomes.

PATIENT CONCERNS

This is a case of a 48-year-old smoker who presented with cyanosis in both hands and the right foot, with gangrenous changes. Investigative angiography showed severe vasospasm in the radial and ulnar arteries of the patient's left hand. Progressive cyanosis of the patient's left hand was noted which may eventually require amputation if left untreated.

DIAGNOSES

He was diagnosed with TAO under the Shionoya diagnostic criteria.

INTERVENTIONS

Fasciotomy and necrotic tissue debridement were performed, followed by centrifuged nanofat grafting. The nanofat graft was prepared using Pallua method and deployed with a MAFT-GUN (Dermato Plastica Beauty Co., Ltd., Kaohsiung, Taiwan).

OUTCOMES

Three months later, computed tomography angiography revealed a radial artery patency. The patient's wrist function was preserved with uneventful wound healing.

LESSONS

The regenerative ability of centrifuged nanofat grafts not only helps wound healing but also helps reverse vasospasm and preserve remnant tissue perfusion.

Molecular mechanisms regulating immune responses in thromboangiitis obliterans: A comprehensive review

Thromboangiitis obliterans (TAO) is a thrombotic-occlusive as well as an inflammatory peripheral vascular disease with unknown etiology. Recent evidence has supported the immunopathogenesis of the disease, however, the factors contributing to the altered immune function and vascular tissue inflammation are still unclear. This review was intended to collate the more current knowledge on the regulatory molecules involved in TAO from an immunoreactive perspective. The homeostasis of the immune system as well as a variety of progenitor cell populations appear to be affected during TAO and these alterations are associated with intrinsic signaling defects that are directing to an improved understanding of the crosstalk between angiogenesis and the immune system, as well as the potential of new co-targeting strategies applying both immunotherapy and angiogenic therapy.

Plasma nitric oxide level is correlated with microvascular functions in the peripheral arterial disease

At present there is no widely accepted biomarker for monitoring of vascular functions. The purpose of this prospective study was to investigate the association of some blood biomarkers with vascular reactivity in patients with peripheral arterial diseases (PAD). A prospective evaluation was made of 3 groups comprising a control group of healthy individuals, and patients with PAD caused by either atherosclerosis or Buerger's disease. Microvascular perfusion was examined using laser Doppler imaging of cutaneous erythrocyte flux after iontophoresis of acetylcholine (ACh) and sodium nitroprusside (SNP). The correlation of microvascular reactivity with endothelium-related biomarkers was assessed. ACh-induced and SNP-induced vasodilations were significantly diminished in the PAD groups. The plasma nitric oxide (NO) levels of PAD patients were significantly higher than those of the control group, but asymmetric dimethylarginine, total antioxidant capacity and hydrogen sulphide levels were similar. Plasma NO level was negatively correlated with ACh and SNP-stimulated microvascular flow increase, whereas a positive correlation was detected with blood glucose and glycated hemoglobin (HbA1c) levels in all groups. These results indicate that a high plasma level of NO in PAD patients is associated with diminished endothelium-dependent and independent flow increase in the microvascular bed. An excessive amount of NO-induced nitrosative stress in an inflammatory condition that might be a reason for vascular dysfunction should be taken into consideration in the diagnostic and therapeutic approaches to PAD.

Efficacy of bosentan in patients with refractory thromboangiitis obliterans (Buerger disease): A case series and review of the literature

The cornerstone of therapy in thromboangiitis obliterans (TAO) is complete abstinence from tobacco. In addition to discontinuation of cigarette smoking, very few pharmacological and surgical options of controversial efficacy are available to date. New therapeutic options with greater efficacy are clearly needed to properly manage these patients.In this preliminary study, we assessed the effectiveness and safety of bosentan in a case series of 8 adults with TAO and severe ischemic ulceronecrotic lesions who were treated with bosentan after inadequate response to platelet inhibitors, vasodilators, and intravenous alprostadil. Additionally, we reviewed 18 well-documented patients with refractory TAO treated with bosentan, which was previously reported (PubMed 1965-2015). These 26 patients formed the basis of our present analysis. All were current smokers.The median duration of bosentan treatment (SD) was 4.5 ± 4 months (range 3-16). Eleven patients (42%) were unable to completely abstain from smoking during their follow-up. With bosentan treatment, no new ischemic lesions were observed in the target extremities. A complete therapeutic response was achieved in 80% of patients, whereas a partial response was observed in 12%. Two patients (8%) ultimately required amputation despite treatment.After discontinuation of bosentan, patients were followed for a median of 20 ± 14 months (range 3-60). Two patients whose trophic lesions had healed relapsed.When comparing patients who gave up smoking with those who were unable to completely abstain from smoking during follow-up, no significant differences were found in efficacy outcomes. Four patients (15%) developed adverse events, requiring bosentan discontinuation in 1 case.These preliminary data suggest that bosentan may be considered a therapeutic option for treatment of cases of severe TAO refractory to conventional treatment, and merit further evaluation in larger controlled, randomized clinical studies.

Investigation of the expression of mediators of neovascularization from mononuclear leukocytes in thromboangiitis obliterans

The aim of this study was to investigate the expression of the cytokines, chemokines and effective molecules of peripheral blood mononuclear cells (PBMCs) that play a role in neovascularization in thromboangiitis obliterans (TAO). Lymphocytes from TAO patients ( n = 20) and control subjects (healthy smokers [ n = 16] and non-smokers [ n = 17]) were evaluated using realtime polymerase chain reaction in order to examine the mRNA expression of CXCL1 and interleukin 8 (IL-8; inducers of collateral development by recruitment of circulating progenitor cells [CPCs]), endothelial cell growth factor A (VEGF-A) and inducible nitric oxide synthase (iNOS; inducers of angiogenesis) and interferon gamma (IFN- γ) and vascular endothelial growth factor receptor 1 (VEGFR-1; inhibitors of angiogenesis). CXCL1 expression was significantly higher in the TAO patients than control subjects. The expressions of IL-8, VEGFR-1 and IFN- γ were significantly higher in the TAO patients and smokers than in non-smokers. However, no differences in iNOS and VEGF-A expression were noted. In conclusion, PBMCs from TAO patients expressed cytokines that potentially recruit CPCs and promote arteriogenesis. However, TAO patients typically have low CPC levels, perhaps due to high oxidative stress. Further studies are recommended in order to investigate the efficacy of antioxidant therapy on the outcome of TAO before administration of angiogenic factors.

Oxidative and antioxidative pathways might contribute to thromboangiitis obliterans pathophysiology

Higher oxidative and lower antioxidative markers have been reported in patients with thromboangiitis obliterans (TAO) when compared with healthy control groups. However, the recent literature has not compared the results with healthy smokers, despite the observed effects of cigarette smoke on oxidative and antioxidative pathways. The aim of this study was to determine the oxidative stress status in TAO patients compared with healthy smokers, through direct assessment of the pro-oxidant-antioxidant balance (PAB) assay. The study included 21 patients with TAO, 19 smokers and 17 non-smokers. Comparison between groups revealed a significant increase in PAB value in the TAO group when compared with the smoker (P= 0.001) and non-smoker (P< 0.001) groups. About 95% of TAO cases had PAB value more than 50 units. The PAB value more than 50 might increase the relative risk of TAO presentation about seven folds (relative risk [RR]= 7.464, confidence interval [Cl]= 95%). The increased PAB value in the TAO might be due to impairment of the oxidative and antioxidative pathways. Based on this hypothesis, the effect of cigarette smoke on oxidative stress might be exaggerated in TAO and may lead to inflammatory and thrombotic events. Further studies for evaluating antioxidant therapies on the outcome of TAO are recommended.