The Value of Serum Complement C1q in the Diagnosis of Acute Ischemic Stroke

Clinical value of serum complement component 1q levels in the prognostic analysis of aneurysmal subarachnoid hemorrhage: a prospective cohort study

Objective

To analyze the relationship between serum complement component 1q (C1q) levels and functional prognosis in patients with aneurysmal subarachnoid hemorrhage (aSAH), and to reveal its clinical value.

Methods

In this prospective cohort study, we collected clinical data of aSAH patients admitted to the Department of Neurosurgery, Hangzhou First People's Hospital from January 2020 to October 2022. Parameters such as serum C1q levels, Hunt-Hess grade, modified Fisher grade, and the modified Rankin scale (mRS) at 3 months were included for evaluation. Patients were grouped based on the occurrence of delayed cerebral ischemia (DCI). Spearman rank correlation test and Kruskal-Wallis rank sum test were used to analyze the correlation between serum C1q levels, disease severity, and prognosis. Potential risk factors affecting prognosis and the occurrence of DCI were screened through Independent sample t-test or Mann-Whitney U test. Variables with significant differences (p < 0.05) were incorporated into a logistic regression model to identify independent risk factors affecting prognosis and DCI occurrence. Serum C1q levels were plotted as a ROC curve for predicting prognosis and DCI, and the area under the curve was calculated.

Results

A total of 107 aSAH patients were analyzed. Serum C1q levels positively correlated with Hunt-Hess grade, modified Fisher grade and mRS (all p < 0.001). Significant differences were observed in C1q levels among different Hunt-Hess grade, mFisher grade and mRS (all p < 0.001). Notably, higher serum C1q levels were seen in the poor prognosis group and DCI group, and correlated with worse prognosis (OR = 36.927, 95%CI 2.003-680.711, p = 0.015), and an increased risk for DCI (OR = 17.334, 95%CI 1.161-258.859, p = 0.039). ROC analysis revealed the significant discriminative power of serum C1q levels for poor prognosis (AUC 0.781; 95%CI 0.673-0.888; p < 0.001) and DCI occurrence (AUC 0.763; 95%CI 0.637-0.888; p < 0.001). Higher C1q levels independently predicted a poor prognosis and DCI with equivalent predictive abilities to Hunt-Hess grade and modified Fisher grade (both p < 0.05).

Conclusion

High levels of C1q in the blood is an independent risk factor for poor prognosis and the development of DCI in patients with aSAH. This can more objectively and accurately predict functional outcomes and the incidence of DCI. C1q may have a significant role in the mechanism behind DCI after aSAH.

Elevated Plasma Complement C1q Levels Contribute to a Poor Prognosis After Acute Primary Intracerebral Hemorrhage: A Prospective Cohort Study

Objective

The complement cascade is activated early following intracerebral hemorrhage (ICH) and causes acute brain injury. We intended to explore the effects of plasma complement component 1q (C1q) levels on hemorrhagic severity and functional outcome in ICH patients.

Methods

In this prospective cohort study, we measured the plasma C1q levels of 101 ICH patients and 101 healthy controls. The Glasgow Coma Scale (GCS) score and hematoma volume were used to assess the ICH severity. Poor prognosis was referred to as a Glasgow Outcome Scale (GOS) score of 1-3 at three months following a stroke. A multivariate logistic regression model was configured to determine the independent relation of plasma C1q levels to severity and poor prognosis. Under receiver operating characteristic (ROC) curve, prognostic capability of plasma C1q levels was evaluated.

Results

There was a significant elevation of plasma C1q levels in patients, as compared to controls [median (percentiles 25th-75th), 225.04 mg/l (156.10-280.15 mg/l) versus 88.18 mg/l (70.12-117.69 mg/l); P<0.001]. Plasma C1q levels of patients were independently related to GCS score (t =-3.281, P=0.001) and hematoma volume (t = 2.401, P=0.018), and were highly correlated with the GOS score at 3 months post-stroke (r=-0.658, P<0.001). Plasma C1q levels were obviously higher in poor prognosis patients than in other remainders (median percentiles 25th-75th), 278.40 mg/l (213.81-340.05 mg/l) versus 174.69 mg/l (141.21-239.93 mg/l); P<0.001). Under the ROC curve, plasma C1q levels significantly discriminated the development of poor prognosis (area under ROC curve 0.795; 95% confidence interval, 0.703–0.869; P<0.001). Using maximum Youden method, plasma C1q levels > 270.11 mg/l distinguished patients at risk of poor prognosis at 3 months with 56.52% sensitivity and 94.55% specificity. Meanwhile, the prognostic predictive ability of plasma C1q levels was equivalent to those of GCS score and hematoma volume (both P>0.05). Moreover, plasma C1q levels > 270.11 mg/l independently predicted a poor prognosis at 3 months (odds ratio, 4.821; 95% confidence interval, 1.211-19.200; P=0.026).

Conclusion

Plasma C1q levels are closely related to the illness severity and poor prognosis of ICH at 3 months. Hence, complement C1q may play an important role in acute brain injury after ICH and plasma C1q may represent a promising prognostic predictor of ICH.

Elevated Serum Complement C1q Levels After Traumatic Brain Injury and Its Association with Poor Prognosis

OBJECTIVE

Complement C1q is implicated in neuroinflammation. We intended to discern the relationship between serum C1q levels and severity in addition to prognosis following traumatic brain injury (TBI).

METHODS

In this prospective, observational study, serum C1q levels were quantified in 188 TBI patients and 188 healthy controls. Glasgow coma scale (GCS) and Rotterdam computed tomography (CT) classification were used as clinical and radiological indicators of severity. Patients with extended Glasgow outcome scale (GOSE) score of 1-4 at 6 months after trauma were considered to have a poor outcome. Multiple logistic regression model was built to ascertain the independent association of serum C1q levels with 6-month poor outcome. Receiver operating characteristic (ROC) curve was configured for analysis of prognostic capability with respect to serum C1q levels.

RESULTS

TBI patients exhibited substantially higher serum C1q levels than controls (median, 223.9 mg/l versus 75.4 mg/l). Serum C1q levels of patients were tightly correlated with GCS score (r = -0.671), Rotterdam CT classification (r = 0.604) and GOSE score (r = -0.581). An area under the ROC curve was yielded of 0.793 (95% confidence interval = 0.728-0.849), and serum C1q levels above 345.5 mg/l discriminated the risk of 6-month poor outcome with 59.6% sensitivity and 92.6% specificity. Serum C1q levels above 345.5 mg/l retained as an independent predictor for 6-month poor outcome with odds ratio of 4.922 (95% confidence interval = 1.552-15.606; P = 0.017).

CONCLUSION

Elevated serum C1q levels are closely correlated with traumatic severity and independently predicted the risk of long-term poor prognosis after TBI.

Elevated Serum C1q Levels in Children With Sepsis

Objective: To analyze the serum complement C1q levels in children with sepsis, and explore the suggestive effect of serum C1q levels on the condition of children with sepsis. Methods: The clinical and laboratory data of children with sepsis (n = 95) and healthy children (n = 71) in Renmin Hospital of Wuhan University from January 2019 to October 2019 were collected, and each index of the two groups was compared. Then we divided children with sepsis into three subgroups based on the Pediatric Critical Illness Score (PCIS): non-critical group, critical group, and extremely critical group. The serum C1q and PCT levels of the three subgroups were analyzed, and the correlation analysis was carried out between the levels of serum C1q and PCT levels as well as PCIS among children with sepsis. Finally, we analyzed the serum C1q levels of septic children infected by different pathogens. Results: The serum C1q levels of children with sepsis were significantly higher than those of healthy children (median 198.4 vs. 186.2 mg/L, P < 0.001). In the analysis of subgroups, the serum C1q levels of non-critical group, critical group, and extremely critical group septic children were 182.80 (166.75, 195.85) mg/L, 219.90 (209.10, 246.40) mg/L and 249.95 (239.10, 272.25) mg/L, respectively, which were correlated with the severity of the disease. At the same time, we also found that serum C1q in children with sepsis was positively correlated with PCT levels (r = 0.5982, P < 0.001), and negatively correlated with PCIS score (r = -0.6607, P < 0.001). The serum C1q levels of septic children with bacterial infections, mycoplasma infections, viral infections, and co-infection were higher than those of the control group (P < 0.05). Conclusion: The serum levels of C1q in children with sepsis were increased and related to the severity of sepsis, suggesting that C1q may be involved in the occurrence and development of sepsis, which had reference value for the preliminary diagnosis and severity classification of sepsis.

Association of Serum Complement C1q Concentration with Severity of Neurological Impairment and Infarct size in Patients with Acute Ischemic Stroke

BACKGROUND

Inflammation occurs after acute ischemic stroke (AIS), and complement C1q is involved in inflammation. However, studies about the association of complement C1q with AIS are still rare. The aim of our study is to investigate the relationship between serum C1q concentration and the clinical severity of AIS.

METHODS

A total of 1294 patients were enrolled in our study, including 647 patients with AIS and 647 non-stroke controls. The infarction volume of AIS was assessed by the diameter of maximum transverse section (DMTS) based on diffusion-weighted imaging (DWI) of brain magnetic resonance imaging. Neurological impairment was assessed by the National Institute of Health Stroke Scale (NIHSS). The association of serum C1q levels with DMTS or NIHSS was investigated by Pearson's or Spearman's correlation analysis.

RESULTS

Serum C1q levels of patients with AIS were significantly higher than those of individuals without AIS. Serum levels of C1q were associated with DMTS (r=0.511, p<0.001) and NIHSS (r=0.433, p<0.001) among patients with AIS.

CONCLUSION

Serum C1q concentration was positively associated with DMTS and NIHSS of patients with AIS.

Is there a link between genetic defects in the complement cascade and Porphyromonas gingivalis in Alzheimer's disease?

Defects, as determined by Genome-Wide Association Studies (GWAS), in the complement cascade of innate immunity have been suggested to play a key role in Alzheimer's disease (AD). These defective genes encode sub-component 1s (C1s), complement receptor 1, complement component 9, and clusterin, a fluid-phase regulatory protein. A dysregulated complement cascade has been shown to relate to cell activation, defective complement mediated clearance and possible cognitive decline in AD patients. Porphyromonas gingivalis, a putative keystone pathogen of periodontal disease, has been reported to be associated with human AD. The inflammatory burden following experimental oral infection in mice and putative entry of this bacterium into the brain appears to drive the formation of amyloid-beta plaques and neurofibrillary tangles with loss of cognition. P. gingivalis is a master of immune subversion in this inflammatory cascade and may establish microbial dysbiosis where it is located. Here we discuss if P. gingivalis may enhance the detrimental effects of the defective GWAS complement cascade protein genes.