Role of complement activation in the pathogenesis of severe cardiorenal injury in patients with primary malignant hypertension / 中华肾脏病杂志

ABSTRACT

Objective:To investigate the role of complement activation in the pathogenesis of primary malignant hypertension (MHT) with nephrosclerosis complicated with severe cardiorenal injury.Methods:Data of MHT patients with nephrosclerosis proven by biopsy from January 2010 to December 2020 in the Beijing Anzhen Hospital, Capital Medical University were retrospectively analyzed. The expressions of complement-related component C4d, C1q, complement factor H-related protein 5, C3c and C5b-9 were detected by immunohistochemical staining. According to whether the patients were complicated with acute heart failure (AHF) and/or acute kidney injury (AKI), they were divided into severe cardiorenal injury group and non-severe cardiorenal injury group. The differences of clinicopathological data between the two groups were compared. According to the degree of C4d deposition in renal tissues, patients were divided into C4d diffused deposition group and non-C4d diffused deposition group. The severity of cardiorenal injury and the pathological characteristics of thrombotic microangiopathy in renal tissues were compared between the two groups.Results:A total of 33 patients were enrolled in this study, of which 17 cases (51.5%) were complicated with severe cardiorenal injury; AHF occurred in 16 patients (48.5%), AKI occurred in 8 patients (26.7%), and AHF and AKI were combined in 7 patients (21.2%). Compared with non-severe cardiorenal injury group, patients in severe cardiorenal injury group had higher levels of baseline lactate dehydrogenase [326.0 (217.0, 366.0) IU/L vs 197.0 (165.0, 220.0) IU/L, Z=37.000, P=0.002] and hemoglobin [(143.6±24.0) g/L vs (106.4±24.7) g/L, t=38.500, P<0.001], lower levels of 12 h urinary incontinence osmolality [400.0 (342.5, 504.0) mmol/L vs 476.0 (432.3, 616.5) mmol/L, Z=72.000, P=0.021] and serum albumin [(36.2±9.4) g/L vs (43.2±6.2) g/L, t=6.423, P=0.017], and thicker left ventricular posterior wall [(14.0±2.1) mm vs (12.1±1.1) mm, t=6.552, P=0.018]. The immunohistochemical results of kidney tissue showed that the proportions of C4d and C5b-9 diffused deposition in severe cardiorenal injury group were significantly higher than those in non-severe cardiorenal injury group (5/16 vs 0/15, P=0.043; 12/16 vs 5/15, P=0.032). Compared with non-C4d diffused deposition group, C4d diffused deposition group had higher incidence of AHF (5/5 vs 10/26, P=0.018), poorer heart function, more severe ventricular remodeling, and shorter history of hypertension [2.0 (0, 12.0) months vs 48.0 (9.5, 84.0) months, Z=22.500, P=0.022]. Conclusions:The incidence of severe cardiorenal injury in MHT patients with nephrosclerosis is about 51.5%. The proportion of diffuse deposition of complement activated components in renal tissues in patients with severe cardiorenal injury is higher than that in patients with non-severe cardiorenal injury. Overactivation of complement may be involved in the pathogenic process of severe heart and kidney injury caused by MHT.