链球菌感染与银屑病相关性探究

银屑病是一种临床常见的慢性反复发作性皮肤病,治疗困难,常罹患终身,病因复杂。研究发现,链球菌感染与银屑病密切相关,链球菌感染可参与银屑病遗传和免疫发病机制,抗链球菌治疗可明显改善银屑病伴链球菌感染患者预后。本文就链球菌感染与银屑病相关性作一综述。     

链球菌感染引发银屑病的有关机制

银屑病是一种具有特征性皮损的慢性炎症性皮肤病，涉及发病机制的众多因素中，遗传、感染及免疫与其关系密切。对与链球菌感染有关银屑病可能涉及的遗传，细菌及体液免疫异常机制进行综述。     

链球菌感染引发银屑病的有关机制

银屑病是一种具有特征性皮损的慢性炎症性皮肤病 ,涉及发病机制的众多因素中 ,遗传、感染及免疫与其关系密切。对与链球菌感染有关银屑病可能涉及的遗传 ,细胞及体液免疫异常机制进行综述     

链球菌感染诱发银屑病的研究现状

银屑病与链球菌感染的相关研究是近年来银屑病的研究热点之一。银屑病是一类由T淋巴细胞介导的自身免疫性疾病，链球菌抗原是T细胞的活化抗原之一，链球菌抗原可在易感人群中诱发或加重银屑病和使银屑病慢性持续存在。HLA的遗传多态性，如HLA—DR可能与此有关。本文就链球菌感染诱发银屑病的研究现状作一综述。     

金黄色葡萄球菌与银屑病的关系及派瑞松外用的疗效

银屑病是一种病因不明的慢性炎症性疾病，可能与环境、创伤、感染、应激有关。针对感染因素，目前研究最多的是金黄色葡萄球菌和链球菌感染，尤其是儿童点滴型银屑病与链球菌有关已被证实，皮肤感染金黄色葡萄球菌与银屑病的发病报道较少。为了进一步探讨金黄色葡萄球菌在银屑病发病过程中的作用，我科于2001～2004年采用寻常型银屑病患者皮损鳞屑培养来鉴定金黄色葡萄球菌的感染率及外用派瑞松治疗35例，报道如下。     

云南汉族与链球菌感染有关的银屑病患者HLA-DR易感基因研究

目的：发现云南汉族与链球菌感染相关的银屑病患者易感基因，探讨银屑病与感染和遗传的关系。方法：用多聚酶链反应技术及序列特异性引物（PCR-SSP），对36例咽部致病性链球菌培养阳性银屑病患者进行HLA-DR基因分型，并与28例云南汉族正常人HLA-DR分型结果比较。结果：银屑病患者HLA-DR7基因频率比正常人显著增高，HLA-DR15基因频率也增高；20例HLA-DR15阳性患者有19例与HLA-DR7连锁，而正常组无DR7与DR15连锁。结论：云南汉族与链球菌感染有关银屑病患者易感基因与HLA-DR7及DR15关联，推测这两个位点的等位基因连锁以共同对链球菌感染相关银屑病易感性发挥作用。     

扁桃腺摘除术后银屑病复发2例

很多资料表明[1],银屑病的发病和加剧与咽部的链球菌感染有关,受链球菌抗原或超抗原作用的T淋巴细胞发生增殖活化,产生大量的细胞因子,可能是银屑病病理改变的重要原因.     

链球菌抗原刺激的银屑病外周血单个核细胞培养上清液对角质形成细胞的作用

目的 了解链球菌抗原刺激的银屑病外周血单个核细胞(PBMCs)培养上清液对角质形成细胞的作用以探讨链球菌感染后的银屑病的发病机制。方法 ^3H—TdR掺入法检测PBMCs培养上清液对角质形成细胞DNA合成的影响；免疫组织化学方法检测细胞间教附因子1(ICAM—1)和人类白细胞抗原DR分子(HLA—DR)表达。结果 银屑病患者链球菌抗原刺激的PBMCs培养上清液对角质形成细胞的促增殖作用较对照组显著增强，并能诱导角质形成细胞表达HLIA—DR和ICAM—1分子。结论 受链球菌抗原刺激的银屑病PBMCs培养上清液可促进角质形成细胞增殖和活化，可能是链球菌感染之后银屑病发病的重要原因。     

银屑病与心血管疾病的流行病学相关性

银屑病是一种慢性复发性炎症性皮肤病,病因不明,由遗传、免疫及环境等诸多因素共同作用所致。研究报道表明银屑病患者常常并发心血管疾病(动脉粥样硬化、冠心病、心肌梗死、高血压等),银屑病可能是心血管疾病的危险因素。研究银屑病与心血管疾病发病的相关性,有利于进一步阐明银屑病发病机制以及银屑病的综合防治。该文对银屑病与心血管疾病流行病学相关性进行了简要综述。     

银屑病治疗进展

银屑病为一原因不明的慢性皮肤病，它的发生和发展主要与感染、内分泌、代谢障碍、免疫异常、多基因遗传和精神等因素有关。近年来随着对其病因认识的深入，银屑病的治疗也取得较大进展，现综述如下。1抗感染治疗 1．1抗细菌治疗咽喉部链球菌感染是诱发急性点滴型银屑病的重要因素。Tokyura等体外测定外周血单核细胞对链球菌超抗原的反应，发现局部链球菌感染可释放超抗原，引起相关T细胞暂时性活化。     

Bedeutung von Streptokokken für die Psoriasispathogenese

Infections with Streptococcus pyogenes are highly relevant among the environmental factors that contribute to first onset or relapses of psoriasis in predisposed individuals. Streptococcal angina or pharyngitis, but also perianal streptococcal dermatitis, vulvovaginitis or balanoposthitis are potential causes. Several mechanisms such as molecular mimicry or superantigens may be involved. Many patients develop a chronic streptococcal infection or colonization that may result from the ability of streptococci for intracellular uptake and persistence in epithelial cells. Whether and under what conditions a curative treatment of streptococcal infection by tonsillectomy or antibiotic treatment may affect the course of psoriasis, as proposed by several observations, needs to be determined in more detail by clinical trials.     

Psoriasis in children

Psoriasis in children 16 years of age and younger is common. Frequently the disease is associated with a positive family history and often appears as acute guttate psoriasis. Acute guttate psoriasis is seen commonly after streptococcal infection of the upper respiratory tract, but may be associated with other viral and bacterial diseases as well. Acute guttate psoriasis responds well to treatment but often recurs as more typical small- or large-plaque disease. The treatment of childhood psoriasis should be simple and, if the disease is significant, carried out in the hospital. Results are much more impressive in hospitalized patients than in outpatient settings. Topical corticosteroids should be used only for short periods of time, whereas tar, ultraviolet light, and anthralin have much longer beneficial effects.     

Subclinical microbial infection in patients with chronic plaque psoriasis

Epidemiological evidence implicates bacterial infection as a common triggering stimulus for psoriasis. Recent studies suggest that continuing, subclinical streptococcal and staphylococcal infections might be responsible not only for relapse of acute guttate psoriasis but also for a new episode of chronic plaque psoriasis. In this study 195 patients suffering from a severe form of chronic plaque psoriasis hospitalized between 1996 and 1998 were examined. The presence of subclinical microbial infection of the upper respiratory tract was studied by the cultivation of pathogens from this area. Patients with other provoking factors, such as a positive history of taking any drugs that may exacerbate psoriasis, endocrine and metabolic factors, alcohol abuse, trauma, dental focus and clinically evident bacterial infection, were excluded. Subclinical streptococcal and/or staphylococcal infections were detected in 68% of tested patients and in only 11% of the control group. The results of this study indicate that subclinical bacterial infections of the upper respiratory tract may be an important factor in provoking a new relapse of chronic plaque psoriasis. Searching for, and eliminating, microbial infections could be of importance in the treatment of psoriasis.     

Investigation of cytomegalovirus and human herpes viruses 6 and 7 as possible causative antigens in psoriasis

Psoriasis is probably a T-cell-mediated autoimmune disease. Infectious models of autoimmune diseases have been proposed and in psoriasis, it has been suggested that there may be molecular mimicry between streptococcal antigens and epidermal keratins. The immunological profile of stable psoriasis plaques suggests, however, that viral antigens may be important. We investigated, using polymerase chain reaction techniques, whether DNA from either cytomegalovirus (CMV) or human herpes viruses (HHV) 6 and 7 is present in the skin of patients (n = 10) with chronic plaque psoriasis. We also investigated 29 patients for the presence of serum IgG to CMV. We found no evidence of CMV or HHV 7 DNA in psoriasis plaques although DNA for HHV 6 was detected in both involved and uninvolved skin in 1 out of 10 patients. There was no statistically significant increase in prior CMV infection, as assessed by the presence or absence of serum IgG to CMV, in psoriasis, compared to our local population. Although there is circumstantial evidence that viral antigens may be important in the pathogenesis of psoriasis we found no evidence to link infection with CMV or HHV 6 and 7 with subsequent development of chronic plaque psoriasis.     

HLA Cw*06 is not essential for streptococcal-induced psoriasis

BACKGROUND: Streptococcal throat infections and HLA Cw6 (Cw*06) have been implicated in the pathogenesis of psoriasis, particularly in the guttate form. OBJECTIVES: To study 105 Irish patients with psoriasis to investigate the relationship between streptococcal infections and Cw*06. METHODS: The patients were divided into two groups: those with guttate psoriasis or guttate flare (guttate group, GG, n=64) and those with chronic plaque psoriasis (chronic plaque group, CPG, n=41). RESULTS: The incidence of Cw*06 was 86% in the GG and 73% in the CPG, which was not significantly different (P=0.1725) but the incidence in both groups was significantly higher than in an Irish control group (18%) (P<0.0001 vs. GG and P<0.0001 vs. CPG). Evidence for streptococcal infection was higher in the GG (56%) than in the CPG (32%) (P=0.0231). Of those patients with evidence of streptococcal infection, 30 of 36 GG (83%) and nine of 13 CPG (69%) patients possessed the Cw*06 genotype. CONCLUSIONS: Thus, not all patients with streptococcal-related psoriasis carry Cw*06. The role of Cw*06 in psoriasis, if any, has yet to be determined.     

The role of streptococcal infection in the initiation of guttate psoriasis.

BACKGROUND AND DESIGN--Although the association between streptococcal infection and guttate psoriasis is well known, to date there has been little information on whether only limited groups and/or serotypes of beta-hemolytic streptococci are involved. One hundred eleven patients with a sudden onset or deterioration of psoriasis were investigated for evidence of streptococcal infection. Of these patients, 34 had acute guttate psoriasis, 30 had a guttate flare of chronic psoriasis, 37 had chronic plaque psoriasis, and 10 had other types of psoriasis. RESULTS--Serologic evidence of recent streptococcal infection was present in 19 (58%) of 33 patients with acute guttate psoriasis compared with seven (26%) of 27 patients with guttate exacerbations of chronic psoriasis. Streptococcus pyogenes was isolated from 19 (17%) of all 111 patients (9 [26%] of 34 with acute guttate psoriasis, four [13%] of 30 with guttate exacerbations of chronic psoriasis, and five [14%] of 37 patients with chronic psoriasis) compared with seven (7%) of 101 of a control population of patients being seen for treatment of viral warts. Other beta-hemolytic streptococci were found with equal frequency in the study and control populations. Thirteen isolates of 10 different streptococcal serotypes were obtained from the 64 patients with guttate psoriasis. These serotypes were similar in distribution and prevalence to those present in the local community. CONCLUSIONS--This study confirms the strong association between prior infection with S pyogenes and guttate psoriasis but suggests that the ability to trigger guttate psoriasis is not serotype specific.     

Treatment of Psoriasis in Children: Is There a Role for Antibiotic Therapy and Tonsillectomy?

Numerous studies implicate subclinical or recurrent streptococcal infection as a trigger or maintenance factor in the pathogenesis of psoriasis in children. The purpose of this article is to review the efficacy of antibiotic therapy and tonsillectomy as treatments for childhood psoriasis. Clinical trials assessing the efficacy of antibiotics or tonsillectomy as treatments for childhood psoriasis were identified with a search of the medical literature and the results were compared. Only one controlled clinical trial was identified and it did not find a significant effect of antibiotic treatment on psoriasis. In other studies, the percentage of psoriasis patients who experienced disease clearance with antibiotic therapy ranged from 0% to 55%, with no patients experiencing disease worsening during treatment. No controlled trials of tonsillectomy for psoriasis were identified. The percentage of patients who experienced disease clearance after tonsillectomy in uncontrolled trials ranged from 32% to 53% and a similar percentage reported significant improvement in their psoriasis, with a maximum of 7% noting worsening of the disease after the operation. The available evidence does not demonstrate the efficacy of either antibiotic therapy or tonsillectomy in the treatment of childhood psoriasis. Because these treatments are relatively benign compared to other treatments for severe psoriasis, the use of antibiotic therapy or tonsillectomy may still be worth considering, especially for those patients with recurrent streptococcal infections that seem to trigger or maintain their skin disease.