Large vessel calcification in Takayasu arteritis

Rheumatology experience with FDG PET / CT in inflammation of unknown origin: a single - centre report for determining factors associated with diagnostic precision

BACKGROUND / AIM: The use of PET / CT is becoming more common in the elucidation of inflammatory processes in which the underlying cause cannot be determined by conventional examinations. Although PET / CT is an effective method for detecting inflammatory foci, the precise diagnosis may not be obtained in all cases. In addition, considering factors such as radiation exposure and cost, it becomes important to identify patients who can get results with PET / CT. In this study, it was aimed to examine the factors that can predict the differential diagnostic value of PET / CT by retrospectively scanning patients who underwent PET / CT for inflammation of unknown origin (IUO) in rheumatology practice.

METHODS

Demographic, clinical and laboratory information of the patients followed up in our clinic and who underwent PET / CT for differential diagnosis were enrolled. Whether they were diagnosed after PET / CT and during the follow - up period, and their diagnoses were examined.

RESULTS

A total of 132 patients were included in the study. A previous diagnosis of rheumatic disease was present in 28.8 % of the patients, and a history of malignancy was present in 2.3 % . The patients were divided into three groups: group 1 patients with increased FDG uptake in PET / CT and diagnosis confirmed by PET / CT, group 2 patients with increased FDG uptake in PET / CT but diagnosis was not confirmed, and group 3 patients without increased FDG uptake in PET / CT. Increased FDG uptake in PET / CT was detected in 73 % of the patients. While PET / CT helped the diagnosis in 47 (35.6 %) patients (group 1), it did not help the diagnosis in 85 (64.4 %) (groups 2 and 3). Thirty - one (65.9 %) of the diagnosed patients were diagnosed with a rheumatologic disease. When the 3 groups were compared, male gender, advanced age, CRP levels, presence of constitutional symptoms, SUVmax values and number of different organs with increased FDG uptake were higher in Group 1. Sixty - six percent and 74 % of the patients in groups 2 and 3 were not diagnosed during the follow - up period. No patient in group 3 was diagnosed with malignancy during follow - up.

CONCLUSION

PET / CT has high diagnostic value when combined with clinical and laboratory data in the diagnosis of IUO. Our study revealed that various factors can affect the diagnostic value of PET / CT. Similar to the literature, the statistically significant difference in CRP levels shows that patients with high CRP levels are more likely to be diagnosed with an aetiology in PET / CT. Although detection of involvement in PET / CT is not always diagnostic, there was an important finding that no malignancy was detected in the follow - up in any patient without PET / CT involvement. Key points • PET / CT is an effective method for detecting inflammatory foci. • PET / CT has proven to be effective in the diagnosis of rheumatological diseases, the extent of disease and the evaluation of response to treatment. • Indications for the use of PET / CT in the field of rheumatology and the associated factors and clinical features supporting the diagnosis with PET / CT are still to be fully clarified. • In routine practice, with PET / CT, both delays in diagnosis and examinations performed during diagnosis and the cost can be reduced.

2-deoxy-2[18F]fluoro-D-glucose positron emission tomography-computed tomography in rheumatological diseases

2-deoxy-2[18F]fluoro-D-glucose (FDG) PET-CT has revolutionized oncological imaging. The cellular processes that make cancer cells visible on FDG PET-CT also occur in a number of inflammatory cells. Exploiting this phenomenon has led to a growth of evidence supporting the use of FDG PET-CT in a wide range of infective and inflammatory diseases. Rheumatological diseases can affect multiple sites within the musculoskeletal system alongside multi-organ extra-articular disease manifestations. Inflammation is central to these diseases, making FDG PET-CT a logical choice. In this review article we describe the various applications of FDG PET-CT in rheumatological diseases using illustrative examples to highlight the beneficial role of FDG PET-CT in each case.

Reduction of Calciprotein Particles in Adults Receiving Infliximab for Chronic Inflammatory Disease

Patients with chronic inflammatory diseases (CID) experience accelerated loss of bone mineral density, which is often accompanied by increased vascular calcification. These disturbances can be attenuated by therapies for inflammation, such as the tumor necrosis factor inhibitor infliximab. Calciprotein particles (CPP) are circulating colloidal aggregates of calcium and phosphate together with the mineral-binding protein fetuin-A, which have emerged as potential mediators of vascular calcification. The precise origins of serum CPP are unclear, but bone turnover may be an important source. In this longitudinal observational study, we studied patients with CID undergoing treatment with infliximab to assess the temporal relationship between bone turnover and circulating CPP. Ten patients with active CID receiving infliximab induction therapy and an additional 3 patients with quiescent CID on maintenance infliximab therapy were studied for 8 weeks with repeated measures of bone turnover markers as well as CPP (calciprotein monomers [CPM], primary CPP [CPP-I], and secondary CPP [CPP-II]). Therapeutic response was appraised using validated disease activity scores. At baseline, those with active CID had elevated markers of bone resorption and suppressed bone formation markers as well as higher CPM and CPP-I compared with those with quiescent CID. In responders, there was an early but transient reduction in resorption markers by week 1, but a more sustained increase in bone formation markers compared with non-responders at week 8. This was accompanied by reductions in CPM (β = -6.5 × 10³ AU [95% CI -11.1, -1.8], p = 0.006) and CPP-I (β = -23.4 × 10⁴ particles/mL [95% CI -34.8, -11.9], p < 0.001). In contrast, no significant changes in any markers were observed in non-responders or those receiving maintenance therapy. Thus, CPP have a dynamic association with changes in bone turnover in response to infliximab therapy, adding to accumulating evidence of the role of bone as a determinant of systemic levels. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Vascular calcification in patients with large-vessel vasculitis compared to patients with hyperlipidemia

OBJECTIVE

Calcification of the coronary arteries, aorta, and branch vessels can occur in both large-vessel vasculitis (LVV) and atherosclerosis. The study objective was to determine the location and amount of vascular calcification in patients with LVV versus hyperlipidemia (HLD) and to identify risk factors associated with vascular calcification in LVV.

METHODS

Patients with giant cell arteritis (GCA), Takayasu's arteritis (TAK), and HLD underwent non-contrast computed tomography of the aorta and branch vessels. Vascular calcification in 14 specific arterial territories (4 segments of the aorta, 9 branch arteries, and the coronary arteries) was quantified throughout the large arteries by a cumulative Agatston score. Multivariate linear regression analyses were used to identify associations between traditional and disease-specific risk factors and total Agatston score.

RESULTS

A total of 88 subjects, including GCA (n = 29); TAK (n = 22); and HLD (n = 37), participated. Prevalence of vascular calcification in the aorta and branch vessels significantly differed in the coronary arteries (HLD = 67%, GCA = 35%, TAK = 9%, p < 0.01). Total Agatston scores were higher in GCA (median 3260, range 25-18,138) versus HLD (460, 19-17,215) (p < 0.01) but did not significantly differ between GCA and TAK (1944, 52-47,520) (p = 0.53). In multivariable regression analysis, age, type of vasculitis, and prednisone use was associated with vascular calcification in LVV.

CONCLUSION

The prevalence of coronary artery calcification is lower in LVV compared to HLD, but the amount of total vascular calcification throughout the large arteries is greater in LVV. Both traditional and disease-specific risk factors are associated with vascular calcification in LVV.

[18F]-Sodium fluoride uptake in Takayasu arteritis

BACKGROUND

While 18F-fluorodeoxyglucose and 18F-sodium fluoride with positron emission tomography relate with inflammation and calcification, their role in the assessment of patients with Takayasu arteritis has not yet been studied.

METHODS

We present 5 patients with suspected active metabolic disease who underwent PET with 18F-fluorodeoxyglucose and 18F-sodium fluoride in order to explore the locations and correlations of 18F-fluorodeoxyglucose and 18F-sodium fluoride uptakes. Diagnosis of metabolic active disease was based on 18F-fluorodeoxyglucose uptake.

RESULTS

We studied 3 female patients and 2 male patients. Median age was 29 years (min: 19 max: 63). In areas with atherosclerotic plaques, we found a negative correlation between 18F-sodium fluoride and 18F-fluorodeoxyglucose uptakes (r = -0.78) (P = .001). Meanwhile, in areas with only metabolic active disease, we found a positive correlation between 18F-sodium fluoride and 18F-fluorodeoxyglucose uptakes (r = 0.94) (P = .019).

CONCLUSIONS

In Takayasu arteritis, 18F-sodium fluoride uptake can document different stages of metabolic disease, even in the absence of active metabolic disease or symptoms.

Abnormal molecular response to Takayasu arteritis causing extensive large-vessel calcification

Takayasu arteritis is a large-vessel vasculitis that often results in pulselessness due to fibrotic stenoses. Whereas minor calcification is sometimes seen with Takayasu arteritis, it rarely causes stenosis. Extensive calcification resulting in malperfusion is exceedingly rare and has been attributed to disorders in calcium trafficking in a chronic inflammatory state. We report an unusual case of rapidly progressive and extensive aortic calcification in the setting of Takayasu arteritis.

The role of fetuin-A in mineral trafficking and deposition

Calcium and phosphate are the principle ions involved in the deposition of mineral in the human body. Inhibitors of mineralisation are essential for the prevention of ectopic mineral precipitation and deposition. In the past decade, through in vitro, in vivo and clinical observation studies, we have come to appreciate the importance of fetuin-A (Fet-A), a circulating glycoprotein, in preventing ectopic calcium phosphate mineralisation. Moreover, the detection of Fet-A-containing mineral complex, termed calciprotein particles (CPPs), has provided new ways to assess an individual's calcific risk. The pathophysiological significance of CPPs in disease states is yet to be defined, but it provides an exciting avenue to further our understanding of the development of ectopic mineralisation.