POS1327 AMYLOID STORM DEVELOPS IN PATIENTS WITH AA AMYLOIDOSIS AND ASSOCIATED WITH HIGHER AMYLOID BURDEN AND INCREASED MORTALITY

BackgroundAmyloid storm is an emerging condition which was described recently also associated with poor prognosis in patients (pts) with AA amyloidosis (AA-a).ObjectivesWe herein aimed to evaluate the amyloid storm and its associated factors in pts with AA-a.MethodsWe retrospectively evaluated AA-a pts who followed in our tertiary referral amyloidosis center. Diagnosis of AA-a was made by Congo red straning and immunohistochemistry. Amyloid storm was defined as follows; developing within two weeks, increase in creatinine and proteinuria levels at least two times from baseline or reach the CRP levels more than 10 times [1].ResultsData of 175 pts with AA-a were evaluated and after exclusion of 11 pts who had missing data, 164 pts were included into the analysis. We identified 9 pts (5.5%; of 4 male) who developed amyloid storm. Five pts were FMF-associated AA-a (FMF-AA) and 4 pts were non-FMF-AA (two pts had ankylosing spondylitis, one patient idiopathic and one patient non-FMF periodic fever syndrome) (p=0.1). Median±interquartile range (IQR) patient age, diagnosis age of FMF and amyloidosis were lower in pts had amyloid storm than had not, but they were not statistically different (p=0.2, p=0.3 and p=0.2 respectively). All pts were M694V homozygous among FMF-AA. Etiology of amyloid storm was infection in 5 pts (56%), treatment non-adherence in 3 pts (33%) and surgery in one patient (11%). Overall, 3 pts with amyloid storm died (33%), but mortality was 10% (n=16) in the remaining pts with AA-a. One patient died during the amyloid storm, and others died within one year after the diagnosis of amyloid storm (median 5 months).In univariable analysis, involvement of ≥3 organs, bone marrow involvement and current proteinuria levels (p=0.4, p=0.05 and p=0.04, respectively) were higher; median number of organ involvement and mortality (p=0.09 and p=0.07) were tended to be higher in pts with amyloid storm than those without it. End stage renal disease (ESRD) development was also higher in pts who had amyloid storm (67%; n=6) than in pts who had not (46 % n=71) but did not reach statistical significance (p=0.3). Median±IQR CRP (48 ±77 vs 9 ±17 p=0.08), creatinine (4.8 ±5 vs1.2 ±0.6 p=0.01) and proteinuria (11 ±12 vs 0.85 ±2.3 p=0.02) levels were higher during the amyloid storm than their previous records. In multivariable analysis, amyloid storm was associated with higher mortality (p=0.045 OR 4.6; 95 % CI 1.03-20).In survival analysis, development of amyloid storm tended to be higher in pts with non-FMF-AA compared to FMF-AA (Log-rank p=0.057). Mortality rate was higher in pts who had amyloid storm than those without it (Log-rank p=0.038).ConclusionThis study showed that 5.5% of pts with AA-a may develop amyloid storm, and this condition was associated with higher amyloid burden. Amyloid storm may develop in AA-a pts associated with both FMF and other diseases, and the mortality rate may reach to 33% within one year.References[1]Kukuy et al. (2021). Rheumatology, 60(7), 3235–3242Table 1.Comparison of clinical and laboratory features of pts with and without amyloid stormVariablesAmyloid storm (n=9)Control (n=155)p valueAge*Ɨ37±1045±200.2Gender, male#4 (44)86 (56)0.7Diagnosis#FMF5 (4)122 (96)0.1non-FMF4 (11)33 (89)Organ distribution#Renal9 (100)152 (98)1Gastrointestinal4 (44)33 (21)0.1Heart2/6 (33)32/111 (29)1Liver1 (11)5 (3)0.3Bone marrow2 (22)5 (3)0.05Diagnosis age of FMF* Ɨ17.5±3024±200.3Diagnosis age of AA-a* Ɨ26±2631±220.2Duration of AA-a* Ɨ10±14.611.2±111Number of organ involvement*2±21±10.09≥3 organ involvement#3/5 (60)20/122 (16)0.04Baseline CRP*ĸ proteinuria (g/dL)* creatinine (mg/dL)*10±85.3±4.30.8±0.620±204±5.70.8±0.60.060.90.6Current CRP* ĸ proteinuria* creatinine*2.7±5.2 3.1±231.5±32.7±7.3 0±1.90±1.90.70.040.04Two exon 10 MEFV variant (n=108, %)3 (100)94 (87)0.5M694V homozygous (n=3, %)3 (100)73 (68)0.2ESRD development #6 (67)71 (46)0.3Mortality#3 (33)16 (10)0.07•.*median±IQR Ɨyears #(n, %) ĸmg/LFigure 1.Comparison of survival rate between pts with and without amyloid stormLog-rank: p=0.038Disclosure of InterestsNone declared