Serum amyloid A as a marker of disease activity and treatment response in Takayasu arteritis

Abstract

Assessment of disease activity in Takayasu arteritis (TA) is challenging. We aimed to study utility of serum amyloid A (SAA) to assess disease activity and its association with SAA gene polymorphisms, if any, in our TA patients. Serum of 99 consecutive adult TA patients and 40 healthy controls were assayed for SAA. Depending on the ITAS2010 and ITAS-CRP score, patients were designated as having active disease if ITAS2010 ≥ 2 or ITAS-CRP ≥ 3 and stable disease if ITAS2010 = 0 or ITAS-CRP is ≤1. Clinical ITAS of 0 with raised inflammatory markers scoring a ITAS-CRP of 2 was considered as indeterminate for disease activity assessment. Repeat SAA levels for active group was measured after 6 months from baseline. SAA levels between active and stable disease as well as serial levels were compared. DNA of 40 patients and controls were genotyped for SAA polymorphisms (rs12218, rs2468844) and the allele frequencies were compared. At baseline, SAA levels were higher in patients as compared to controls (137.4 vs 100.8 ng/ml, p = 0.001) and higher in patients with active disease (166.4 ng/ml) than those with stable disease (98.2 ng/ml), p = 0.001. SAA decreased during follow-up in treatment responders (189.9 ng/ml at baseline vs 119.0 ng/ml at follow-up, p = 0.008); in contrast, there was no significant change among non-responders during follow-up. Allelic frequencies of SAA gene polymorphisms did not differ between cases and controls. SAA may be a reliable biomarker to assess disease activity and treatment response in TA.

The C-Reactive Protein/Albumin Ratio and Complete Blood Count Parameters as Indicators of Disease Activity in Patients with Takayasu Arteritis

“…However, currently, there are no reliable laboratory biomarkers to monitor disease activity. Recent studies have shown that levels of the interleukins, IL-6, IL-8, and IL-18, and levels of serum amyloid A (SAA) were significantly increased in patients with Takayasu arteritis and could be used to monitor disease activity [15,16]. Misra et al .…”

Biomarkers in Vasculitides of the Nervous System

“…At baseline, there were higher SAA levels in individuals with TA than in healthy controls, and also higher values in patients with active disease compared to those with stable disease. SAA exhibited a decreasing trend during follow-up in treatment responders, whereas these changes were not observed in non-responders (79). The study was limited by small sample size and a short duration of follow up (79).…”

“…Finally, Nair et al identified serum amyloid A (SAA), an apolipoprotein which belongs to the group of acute phase proteins, as a biomarker to evaluate disease activity and treatment response in TA (79). At baseline, there were higher SAA levels in individuals with TA than in healthy controls, and also higher values in patients with active disease compared to those with stable disease.…”

Regressed coronary ostial stenosis in a young female with Takayasu arteritis: a case report

“…C-reactive protein is produced in the liver in response to interleukin-6, and thus C-reactive protein is not suitable to evaluate inflammatory activity after initiation of tocilizumab. However, serum amyloid A is suitable to evaluate disease activity under tocilizumab treatment [20, 21]. In the present case, serum amyloid A and 18 F-FDG uptake indicated that inflammation remained in the patient.…”