Background: Avascular necrosis (AVN) in ANCA associated vasculitides (AAV) is a rare finding of damage that has not been investigated in detail in terms of risk factors.

Objectives: To investigate the prevalance of AVN risk factors in patients with AAV

Methods: AAV cohort diagnosed according to CHCC, presented with ≥1 organ involvement, being followed-up and treated ≥6 months after diagnosis were included into the study. All symptomatic AVN was demonstrated by MRI. Demographic and clinical data including pre-defined AVN risk factors such as high BMI (≥25), hyperlipidemia, diabetes, smoking status, alcohol intake and cumulative glucocorticoid (GC) exposure were noted into a protocol. Initial BVAS and cumulative VDI were calculated in the majority of cohort. The patients were stratified in accordance to the presence of AVN (AVN+/AVN-). Demographics and AVN risk factors were compared between the groups by using Mann Whitney U test.

Results: The study group consisted of 129 AAV (16 e-GPA, 28 MPA, 85 GPA) patients (63 female) with the mean age at diagnosis 44±15 and mean follow-up time 60±46.7 (6-182) (med 48). Eighteen of 129 (14%) AAV patients developed AVN (2 MPA, 16 GPA). AVN was observed in knee (2), shoulder (1), hip (14) and ankle (1) and bilateral in 66%. Comparison of the AVN risk factors in AAV patients was shown in Table.

Table 1. Comparison of the AVN risk factors in AAV patients

Conclusions: A very high prevalence of AVN was found in our GPA cohort, which is quite higher than the previously reported frequencies (<1%). However, comparison of GC exposure data could not be done between our preliminary analysis and that of previously reported trial results. Other undefined risk factors to AVN such as variables affecting bone metabolism may contribute to observed differences warranting further investigations. Male gender has been identified as a new risk factor in our cohort, which has to be confirmed in large cohorts.

Disclosure of Interest: None declared

DOI: 10.1136/annrheumdis-2015-eular.4860