[Acute Kidney Injury in the Context of Chronic Kidney Disease: Interdisciplinary Aspects]

Acute respiratory diseases (ARDs) are among the most common illnesses of the 21st century and serve a leading cause of temporary disability. They are also a frequent trigger for the development of acute kidney injury (AKI), which, when progressing to acute kidney failure (AKF), requires costly treatment, including hemodialysis. The risk of AKF increases with age, especially in the presence of comorbidities. The proportion of AKF patients in intensive care units reaches 10-15%. This article presents clinical observations of two female patients of middle and advanced age who developed AKF following ARI. In biochemical blood tests, both Patient A (58 years old) and Patient D (85 years old) exhibited significantly elevated levels of C-reactive protein (CRP: 384 mg/L and 285.4 mg/L, respectively), interleukin-6 (IL-6: 197.0 pg/mL and 143 pg/mL, respectively), and D-dimer (3.88 mg FEU/L and 8.11 mg FEU/L, respectively). These changes were accompanied by an increase in serum creatinine (Scr: 339 mol/L and 160 mol/L, respectively) and a marked decrease in glomerular filtration rate (GFR: 12 mL/min and 25 mL/min, respectively). With conservative therapy, the general condition of the patients improved, and there was a significant reduction in CRP levels (17.7 mg/L and 104 mg/L, respectively), IL-6 (48.2 pg/mL and 67.7 pg/mL, respectively), and Scr (64 mol/L and 84.7 mol/L, respectively), as well as an increase in GFR (92 mL/min and 57 mL/min, respectively). However, serum cystatin C and D-dimer levels remained above threshold values throughout dynamic monitoring. CONCLUSION: In patients with severe ARI, the development of AKF is associated with elevated CRP, IL-6, and D-dimer levels. Increased serum cystatin C levels may serve as a predictor of chronic kidney disease in the future.