AB0871 ASSESSMENT OF THE KIDNEYS AND URINARY TRACT DYSFUNCTIONS THAT INCREASE THE RISK OF DEVELOPING CHRONIC KIDNEY DISEASE IN PATIENTS WITH GOUT BASED ON COMPLEX RENAL SCINTIGRAPHY
Authors: Margarita Gromova, Vladimir Tsurko, Anna Kashkadayeva, Svetlana Averinova, Andrey Aliokhin
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background</h3> In 40% of cases patients with gout can develop gouty nephropathy, the "kidney mask" of gout. The newest version of the technology for systemic examination of nephrourological status based on complex renal scintigraphy (SENS-CRS) has been developed at the «N.N.Blokhin National Medical Research Center of Oncology». SENS-CRS at the lowest doses of radiation (0.6 mSv per adult) allows for an in-depth differential analysis of dysfunctions of the renal parenchyma, upper and lower urinary tract which increase the risk of chronic kidney disease (CKD) development. <h3>Objectives</h3> To assess early signs of CKD risk development in patients with gout by SENS-CRS technology. <h3>Methods</h3> We examined 66 patinets with gout. 95% were men (average age 54±9 years). Duration of gout was 8 [4; 11] years. All patients had chronic gouty arthritis, 30% of patients had tophuses. SENS-CRS was carried out on a 2-detector γ-camera with simultaneous recording in 2 projections. In studies of the urinary system domestic radiopharmaceutical (RP) 99mTc-technefor with glomerulo- and 10-15% tubulotropic properties was used. The CRS study consisted of: 1) a basic 21-min functional study; 2) a delayed 21-min study (without the injection of RP) with a preliminary diuresis forcing to identify persistent urodynamic dysfunction. <h3>Results</h3> 16 patients with gout with serum creatinine level of more than 125 μmol/l had established diagnosis of chronic pyelonephritis, glomerulonephritis, urolithiasis, etc. and were allocated into a separate subgroup. In the comparative analysis of these 16 patients and other 50 patients with gout there was reliable distinction only for one indicator D (%), the rate of RP removal from a kidney parenchyma (p &lt; 0,05). There was no significant distinctions for glomerular filtration rate by Reberg, the nuclear indicator (G<sub>ren</sub>) of renal parenchyma concentration function, and other indicators. Renocortical parameter D (%) is one of the earliest highly sensitive markers of intrarenal developments of stagnation at development of serious morphofunctional violations in a parenchyma. In the subgroup of 16 patients the indicator accounted on average D = 48% ± 7% (range 38-55%); in subgroup of 50 patients D = 63% ± 10% (47-89%). According to the CKD-EPI formula and SENS-CRS technology in the subgroup of 16 patients CKD stage II-III was evaluated. In addition to the sign of broken rate of RP removal from a parenchyma (D) when comparing the 2 phases of CRS there was observed a steady sign of stagnation in a parenchyma and groups of upper and/or lower cups: ID = G<sub>calc</sub>/GC &lt; 1. Based on the water test which accelerates diuresis there was a sufficient regulation of urostasis in the renal pelvis revealed at the basic test (IP = G<sub>pelv</sub>/GP &gt; 1,0). This indicated that the functional reserve of the outflow regulation from the kidneys was preserved at these patients. <h3>Conclusion</h3> This functional diagnostics allows one-time control of hemodynamics and concentration function of the parenchyma of each kidney, quantitative and qualitative signs of urodynamic delays in the intra- and post-renal urinary tract. Differentiated analysis SENS-CRS contributes to the timely therapeutic correction as well as referral for consultation to specialists (urologists, nephrologists, gynecologists, etc.). <h3>Disclosure of Interests</h3> Margarita Gromova Speakers bureau: Speaker during conferences in Russian Federation, Vladimir Tsurko Speakers bureau: Speaker during conferences in Russian Federation, Anna Kashkadayeva: None declared, Svetlana Averinova: None declared, Andrey Aliokhin: None declared