Hearing loss due to urate deposition in the middle ear: A case report and literature review

Gout is the most common cause of monoarthritis in men occurring classically in the great toe and the knee.Extra-articular gout manifestations are rare.Only a few cases of head and neck urate crystals deposits have been described in the literature.Precipitations in the middle ear cause conductive hearing loss with common otoscopic anomalies and difficult imaging diagnosis.We report a case of a healthy 58-years-old man with a middle ear urate deposit causing a progressive hearing loss as the very first symptom of gout.The nature of the deposit was unsure on computer tomography(CT)due to atypical density.The final diagnosis was revealed after surgical procedure and histologic examination.A review of the literature is also presented.Seven cases of middle ear urate deposit as the first symptom of gout were found and compared.Progressive conductive hearing loss in middle-aged patients with abnormal otoscopy and middle ear atypical density mass on CT scan must lead to a minimal surgical procedure with a histologic examination to exclude urate crystals deposits.     

hURAT1、SLC2A9、ABCG2与高尿酸血症、痛风的关系及临床意义

高尿酸血症和痛风与肾脏和心脑血管系统疾病的发生、发展关系密切,近年来发病率呈逐年升高趋势,逐渐引起人们的广泛重视。最近研究发现人尿酸盐转运蛋白1(hURAT1)、尿酸转运子SLC2A9和ABC转运蛋白2(ABCG2)三个尿酸盐转运蛋白的基因变异与高尿酸血症和痛风的发生呈高度相关,在疾病发病机制中起到重要的作用。现就hURAT1、SLC2A9和ABCG2与高尿酸血症、痛风的关系及其临床意义进行综述。     

The W258X mutation in SLC22A12 is the predominant cause of Japanese renal hypouricemia

Recently, a urate transporter, hURAT1 (human uric acid transporter 1) encoded by SLC22A12, was isolated from the human kidney. hURAT1 is presumed to play the central role in reabsorption of urate from glomerular filtrate. In the present study, we analyzed SLC22A12 in seven unrelated Japanese patients with renal hypouricemia whose serum level of urate was less than 1.0 mg/dl, and their family members. We performed direct DNA sequencing of the exon and exon-intron boundaries of SLC22A12 using genomic DNA. Six of the seven patients (86%) possess mutations in SLC22A12. In five patients, a homozygous G to A transition at nucleotide 774 within exon 4 of SLC22A12, which forms a stop codon (TGA) at codon 258 (TGG), was identified (W258X). In one patient, the C to T transition within exon 3, which changes threonine at codon 217 to methionine (T217 M), and the W258X mutation were found (compound heterozygote). Thus, among 12 mutational alleles in six patients, 11 were the W258X mutation (92%). Family members with the heterozygous W258X mutation (carriers) show relatively low levels of serum urate. The present study demonstrates that homozygous W258X mutation is the predominant genetic cause of idiopathic renal hypouricemia in Japanese patients.     

中药治疗痛风性肾病疗效的系统评价

目的：探讨中草药治疗慢性尿酸性肾病的疗效及安全性。方法：用计算机对网上电子数据库和手工对参考文献进行检索有关中草药治疗尿酸性肾病的临床试验、系统综述和荟萃分析。结果：共有12项随机临床试验符合标准而纳入研究。8项（67％）试验涉及9个（75％）中草药单用或与降尿酸西药联用显示治疗尿酸性肾病有明显疗效。其中6种（75％）中草药（滋肾汤、化湿泄浊祛瘀汤、降尿酸方、补肾化湿通络汤、活血泄浊汤、痛风1号）加用西药有显著疗效。3种（60％）中草药（威草胶囊、痛风合剂、痛风1号）单用有显著疗效。所有试验均为低质量试验。倒漏斗图形显著不对称，提示存在发表偏畸。结论：本系统综述显示某些中草药单用或与西药联用治疗痛风性肾病有具有一定的疗效，亦无发生严重毒副作用的报道。但由于所纳入试验方法学质量低下等原因，推荐中草药用于治疗痛风性肾病的证据强度不大。其潜在的疗效及安全性还需严格设计的高质量的随机双盲对照试验加以证实。     

痛风病的国内外认识及治疗进展与思考

痛风病是指与高尿酸血症、尿酸盐沉积密切相关的进展性代谢疾病,已成为我国第二大类代谢疾病。通过梳理和总结国内外痛风相关疾病的指南和专家共识以及中医对痛风病的认识,对痛风病的中西医认识进展进行综述。以及基于对痛风病的认识,总结中西医治疗痛风病的研究进展,以期为痛风病的诊疗及研究提供参考。     

Efficacy of Single Low-Dose Rasburicase in Management of Tumor Lysis Syndrome in Leukemia and Lymphoma Patients

BackgroundTumor lysis syndrome (TLS) is a metabolic emergency in hematology patients. The recommended dose of rasburicase for the management of TLS is 0.2 mg/kg per day for 5 days, which is cost prohibitive for many patients. We sought to determine the efficacy of single low-dose rasburicase in the prevention and treatment of hyperuricemia in TLS.Patients and MethodsWe planned a prospective study for the safety and efficacy of fixed (weight based) dose of rasburicase to manage TLS. Patients diagnosed with leukemia/lymphoma with laboratory or clinically confirmed TLS or presence of ≥ 2 high-risk factors and serum uric acid > 7.5 mg/dL were included. The primary endpoint was uric acid normalization (< 7.5 mg/dL) within 24 hours of rasburicase administration.ResultsFifty-five patients were recruited for this study. Pediatric patients (< 18 years) accounted for 43.6% of cases. Rasburicase was provided prophylactically to 43 patients (78.2%) and for treating TLS to 12 (21.8%). Mean ± standard deviation serum uric acid at baseline and 24 hours was 9.2 ± 1.8 mg/dL and 3.2 ± 2.1 mg/dL, respectively. There was significant reduction in the serum uric acid and creatinine (P < .001) within 24 hours of rasburicase administration. The response was maintained up to 72 hours. A single dose of rasburicase was effective in 94.5% of patients. Single low-dose rasburicase led to 95% direct cost savings compared to the recommended dose.ConclusionSingle-dose rasburicase with frequent laboratory monitoring is effective in the management of TLS and offers significant cost reductions.     

无症状高尿酸血症患者尿酸盐晶体致病性相关因素研究进展

无症状高尿酸血症（AH）是以血清尿酸水平升高为特征的一种代谢性疾病。当血清尿酸水平超过饱和值后,尿酸盐晶体就会析出并沉积在关节滑膜、软骨及肾脏等组织诱发急性炎性反应。尿酸盐晶体是用于诊断痛风的金标准,但并非所有尿酸盐晶体沉积的AH患者最终都会发展为痛风。尿酸盐晶体沉积最终是否会引起痛风发作取决于尿酸盐晶体相关致病性基因、机体的免疫状态、软骨损伤以及滑液环境等多重因素的共同作用。明确尿酸盐晶体在AH发展为痛风过程中的致病性相关因素及其触发机制,能为AH患者中痛风高危人群的早期筛查、分层管理及个体化治疗提供依据。     

Gouty flexor tenosynovitis of the hand mimicking atypical mycobacterial infection

Abstract

A 50-year-old Japanese fish dealer presented with painful and swollen fingers. Infectious flexor tenosynovitis with Mycobacterium marinum was suspected. Range of motion was restored after tenosynovectomy and after ofloxacin and clarithromycin were administered. Two years after the operation, the patient presented again with acute inflammation in the same fingers. Histopathological examination revealed gouty tenosynovitis. The preconception that mycobacterial infection occurs often in fish dealers caused us to miss the correct diagnosis of gouty tenosynovitis.     

Inflammatory responses to intradermal crystals in healthy volunteers and patients with rheumatic diseases

Summary The inflammatory response to intradermal injections of urate, pyrophosphate and hydroxyapatite crystals in human forearm skin is described. Patients with rheumatoid arthritis responded normally to urate crystals, and patients with osteoarthritis or pyrophosphate arthropathy responded normally to hydroxyapatite and pyrophosphate crystals respectively. These results suggest that variation in host response to crystals cannot explain the different patterns of crystal-induced disease seen in man. The model, however, is recommended as a safe, simple ethical and reproducible test of inflammation in human subjects.     

A hypothesis on the possible role of interferon in the initiation of acute gouty arthritis attack

There is some evidence that unidentified factors might play a role in the initial events of acute gouty arthritis. Serum interferon activity was found to be high in several arthritides; interferon stimulates the production of prostaglandin E, an established mediator of inflammation. It is postulated that interferon can play a role in the pathogenesis of an acute gouty arthritis.