Kidney Week

Abstract: SA-PO1108

Association of Serum Complement 3 (C3) with Renal Arteriolar Hyalinosis and Blood Pressure-Dependent Proteinuria in Patients with Non-nephrotic CKD

Session Information

• CKD: Epidemiology, Risk Factors, and Prevention - 3
  October 26, 2024 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: CKD (Non-Dialysis)

• 2301 CKD (Non-Dialysis): Epidemiology, Risk Factors, and Prevention

Authors

• Kohagura, Kentaro, Ryukyu Daigaku Igakubu Fuzoku Byoin, Nakagami-gun, Okinawa, Japan

Kentaro Kohagura, MD, PhD

• Oshiro, Nanako, Ryukyu Daigaku Igakubu Fuzoku Byoin, Nakagami-gun, Okinawa, Japan

Nanako Oshiro, MD, PhD

• Shinzato, Yuki, Ryukyu Daigaku Igakubu Daigakuin Igaku Kenkyuka, Nakagami-gun, Okinawa, Japan

Yuki Shinzato, MD

• Zamami, Ryo, Ryukyu Daigaku Igakubu Daigakuin Igaku Kenkyuka, Nakagami-gun, Okinawa, Japan

Ryo Zamami, MD, PhD

• Kusunose, Kenya, Ryukyu Daigaku Igakubu Daigakuin Igaku Kenkyuka, Nakagami-gun, Okinawa, Japan

Kenya Kusunose, MD, PhD

Background

Renal arteriolar hyalinosis may be associated with proteinuria by disrupting the autoregulatory system in the afferent arteriole. Deposition of complement C3 (C3) is commonly seen in hyaline lesions of arteriolosclerosis. Serum C3 has been suggested to play a pathogenic role as an adipocytokine. However, an association of serum C3 with renal arteriolar hyalinois and blood pressure dependent proteinuria in patients with non-nephrotic chronic kidney disease (CKD) is unknown.

Methods

A total of 174 consecutive patients who underwent renal biopsy at our department were considered for the study. We excluded patients with serum albumin less than 3.0 mg/dl, vasculitis, lupus nephritis, etc. leaving us with 122 patients. Arteriolar hyalinosis was assessed using a semiquantitative grading system. We divided the patients into four subgroups based on the high systolic blood pressure (hSBP) and high serum C3 (hC3), defined as equal or above of their median value. We investigated an association of serum C3 with renal hSBP/hC3 subgroups with proteinuria.

Results

Median age, blood pressure, estimated glomerular filtration rate (eGFR), urine protein, and serum C3 were as follows: 42.0 years, 123/74 mmHg, 71.3 ml/min/1.73 m², 0.7 g/gCr and 104.5mg/dl, respectively. Serum C3 was positively associated with body mass index, HbA1c, low-density lipoprotein cholesterol, oxidative stress index, high-sensitivity C-reactive protein (hs-CRP), urine protein, and arteriolar hyalinosis index. In the multiple regression analysis, serum C3, but not C4, was associated with arteriolar hyalinosis index independent of age, sex, and potential confounders (β=0.195, P=0.026). SBP was significantly associated with urinary protein in patients with hC3 but not in those without hC3. In the multiple logistic regression analysis with hC3-/hSBP- as reference, hC3+/hSBP+ was independently associated with high proteinuria, defined as the highest tertile (OR 5.67, 95%CI 1.32-34.29, P=0.02), but its significance disappeared after additional adjustment for the arteriolar hyalinosis index.

Conclusion

These results suggest that serum C3 may be elevated as an adipocytokine and may be associated with increased BP-dependent proteinuria by inducing arteriolar hyalinosis in non-nephrotic CKD patients.