Cooper Chad, Bilbao Jorge E, Said Sarmad, Alkhateeb Haider, Bizet Jorge, Elfar Ahmed, Davalos Olinamyr, Meza Ana T, Hernandez German T
Division of Nephrology & Hypertension, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, Texas, USA.
Pathology Professional Services, El Paso, Texas, USA.
J Nephropathol. 2013 Jul;2(3):196-200. doi: 10.12860/JNP.2013.31. Epub 2013 Jul 1.
Systemic AA amyloidosis is a long-term complication of several chronic inflammatory disorders. Organ damage results from the extracellular deposition of proteolytic fragments of the acute-phase reactant serum amyloid A (SAA) as amyloid fibrils. Drug users that inject drug by a subcutaneous route ("skin popping") have a higher chance of developing secondary amyloidosis. The kidneys, liver, and spleen are the main target organs of AA amyloid deposits. More than 90% of patients with renal amyloidosis will present with proteinuria, nephrotic syndrome, or renal function.
A 37 year-old female presented to the hospital with a one-week history of pain and redness in her right axilla. Her relevant medical history included multiple skin abscesses secondary to "skin popping", heroin abuse for 18 years, and hepatitis C. The physical examination revealed "skin popping" lesions, bilateral costovertebral angle tenderness, and bilateral knee swelling. The laboratory workup was significant for renal insufficiency with a serum creatinine of 5 mg/dL and 14.8 grams of urine protein per 1 gram of urine creatinine. The renal biopsy findings were consistent with a diagnosis of renal amyloidosis due to serum amyloid A deposition and acute tubulointerstitial nephritis.
AA renal amyloidosis among heroin addicts seems to be associated with chronic suppurative skin infection secondary to "skin popping". It is postulated that the chronic immunologic stimulation by one or more exogenous antigens or multiple acute inflammatory episodes is an important factor in the pathogenesis of amyloidosis in these patients. Therefore, AA renal amyloidosis should always be considered in chronic heroin users presenting with proteinuria and renal impairment.
系统性AA淀粉样变性是几种慢性炎症性疾病的长期并发症。器官损伤是由于急性期反应物血清淀粉样蛋白A（SAA）的蛋白水解片段作为淀粉样纤维在细胞外沉积所致。通过皮下途径注射毒品（“皮肤注射”）的吸毒者发生继发性淀粉样变性的几率更高。肾脏、肝脏和脾脏是AA淀粉样沉积物的主要靶器官。超过90%的肾淀粉样变性患者会出现蛋白尿、肾病综合征或肾功能异常。
一名37岁女性因右腋窝疼痛和发红一周入院。她的相关病史包括继发于“皮肤注射”的多处皮肤脓肿、18年的海洛因滥用史以及丙型肝炎。体格检查发现“皮肤注射”损伤、双侧肋脊角压痛和双侧膝关节肿胀。实验室检查显示肾功能不全，血清肌酐为5mg/dL，尿蛋白为每克尿肌酐14.8克。肾活检结果与因血清淀粉样蛋白A沉积和急性肾小管间质性肾炎导致的肾淀粉样变性诊断一致。
海洛因成瘾者中的AA肾淀粉样变性似乎与继发于“皮肤注射”的慢性化脓性皮肤感染有关。据推测，一种或多种外源性抗原的慢性免疫刺激或多次急性炎症发作是这些患者淀粉样变性发病机制中的一个重要因素。因此，对于出现蛋白尿和肾功能损害的慢性海洛因使用者，应始终考虑AA肾淀粉样变性。
