COMPARATIVE ASSESSMENT OF ULTRASOUND INDICATORS OF INTRARENAL BLOOD FLOW IN THE EARLY DIAGNOSIS OF RENAL LESIONS

Study of the opportunities of ultrasound investigation methods in the early diagnosis of kidney lesions.

Ultrasound Proven Monosodium Urate Crystal Deposits in the Joints are Associated with Smaller Kidney Size, Decreased Intrarenal Blood Flow and Arteriosclerotic Type Vascular Changes

Objective: To establish the association between ultrasound (US) burden with articular MSU crystals and renal morphology, blood supply, function and arteriosclerotic carotid arteries alterations in gout patients, individuals with asymptomatic hyperuricemia and no sign of inflammatory arthritis and psoriatic arthritis subjects with asymptomatic hyperuricemia.Methods: 121 consecutive patients were included: 85 patients with gout, 27 subjects with asymptomatic hyperuricemia and 9 psoriatic arthritis patients. Subjects underwent US of both kidneys, common carotid arteries and bilateral US of the joints of the hands, elbows, knees, ankles and feet. For intrarenal blood flow we judged by measuring the renal resistive index (RRI). By US of the carotid arteries were determined intima-media thickness (IMT), common carotid artery resistive index (CCARI) and the presence of atherosclerotic plaques was registered.Results: Individuals with articular US MSU deposits compared to those without had higher RRI (p = 0.035) and smaller kidney size (p = 0.014), but renal parenchymal thickness (p = 0.893), echogenicity (p = 0.291), IMT (p = 0.165), CCARI (p = 0.097), the frequency of nephrolithiasis (p = 0.438) and atherosclerotic plaques (p = 0.830) were similar. Subjects with US evidence of MSU crystals in two or more joint regions had the highest RRI (p = 0.002) and CCARI (p = 0.019). Compared to gout patients the risk of MSU crystal accumulation in the joints of asymptomatic hyperuricemia group was lower by 82.7%, OR = 0.173 (95% CI; 0.060 – 0.498, p = 0.001), while in psoriatic arthritis patients the risk was lower by 82%, OR = 0.180 (95% CI; 0.038-0.861, p = 0.032).Conclusions: This study points out that subjects with larger extent of articular MSU burden have greater vascular stiffness. The accumulation of MSU crystals in the joints may be associated with the accumulation of crystals mainly in the renal interstitium.

The Potential for Renal Injury Elicited by Physical Work in the Heat

An epidemic of chronic kidney disease (CKD) is occurring in laborers who undertake physical work in hot conditions. Rodent data indicate that heat exposure causes kidney injury, and when this injury is regularly repeated it can elicit CKD. Studies in humans demonstrate that a single bout of exercise in the heat increases biomarkers of acute kidney injury (AKI). Elevations in AKI biomarkers in this context likely reflect an increased susceptibility of the kidneys to AKI. Data largely derived from animal models indicate that the mechanism(s) by which exercise in the heat may increase the risk of AKI is multifactorial. For instance, heat-related reductions in renal blood flow may provoke heterogenous intrarenal blood flow. This can promote localized ischemia, hypoxemia and ATP depletion in renal tubular cells, which could be exacerbated by increased sodium reabsorption. Heightened fructokinase pathway activity likely exacerbates ATP depletion occurring secondary to intrarenal fructose production and hyperuricemia. Collectively, these responses can promote inflammation and oxidative stress, thereby increasing the risk of AKI. Equivalent mechanistic evidence in humans is lacking. Such an understanding could inform the development of countermeasures to safeguard the renal health of laborers who regularly engage in physical work in hot environments.

Polymorphism A1166C of AGTR1 Gene and the State of Intrarenal Blood Flow in Patients with Essential Arterial Hypertension 1–2 Degrees

Aim: to study relationship between genetic disorders and features of intrarenal blood flow in patients with essential arterial hypertension (AH) of 1–2 degree. Materials and methods. We examined 100 patients (60 women, 40 men) aged 35 to 58 years with 1–2‑degree essential arterial hypertension (AH) and chronic kidney disease (CKD) stages I–III. Examination included triplex scanning of renal arteries on the ultrasound scanner Vivid-7 Dimension, genotyping of single-nucleotide polymorphism А1166С of the AGTR1 gene by real time polymerase chain reaction (PCR), estimation of glomerular filtration rate (GFR) using CKD-EPI formula. Patients were divided into 2 groups: group 1 included persons with I and II stage CKD (n=65, 25 men and 40 women), group 2 included patients with stages IIIA and IIIB CKD (n=35, 15 men and 20 women). Results. Among patients of group 1 prevailed genotype AA, while among group 2 patients prevailed genotype AC. Speed of blood flow in interlobar renal arteries was higher in the group 1 compared with group 2, while in the group 2 time of acceleration of blood flow was higher than in the group 1. Discussion. The data obtained are indicative of the decrease of systolic, diastolic, and averaged maximal blood flow velocity and the lengthening of acceleration time in patients with higher CKD stage. Conclusions. The presence in the genotype of patients with 1–2‑degree AH of AGTR1 1166С allele may be considered a risk factor of early development of CKD. Lowering of speed characteristics of blood flow and lengthening of the acceleration time in patients with AH can be a criterion of hypertensive nephropathy development.

Effect of Alprostadil on the Prevention of Contrast-Induced Nephropathy: A Meta-Analysis of 36 Randomized Controlled Trials

Contrast-induced nephropathy (CIN) is the third leading cause of acquired acute renal injury in hospitalized patients. Alprostadil plays a role in the maintenance and redistribution of intrarenal blood flow and the excretion of electrolytes and water. However, the effectiveness of alprostadil in preventing CIN remains controversial. Thirty-six articles with a total of 5495 patients were included in this study. Both groups (experimental group and control group) received standard hydration therapy. In the experimental group, patients received different doses of alprostadil. Serum creatinine (SCr), blood urea nitrogen (BUN), estimated glomerular filtration rate (eGFR), cystatin C, creatinine clearance rate (CCr), and β2-microglobulin (β2-MG) were measured at 24, 48, and 72 hours after contrast media injection. The incidence of CIN in the experimental group was significantly lower than that in the control group (6.56% vs 16.74%). The level of SCr, cystatin C, BUN, and β2-MG in the experimental group was lower than those in the control group; CCr and eGFR in the experimental group were higher than those in the control group. This study demonstrated that alprostadil may reduce the incidence of CIN in patients undergoing coronary angiogram and/or percutaneous coronary intervention.