Serum Complement C1q Research Articles

Serum Complement C1q in Egyptian Patients with Incidental Cerebral Small Vessel Disease

Abstract Background Cerebral small vessel disease (CSVD) is associated with increased risk of death and ischemic stroke in patients with atherosclerotic disease. Identifying new biomarkers is mandatory for early diagnosis and proper management. Aim of the Study The aim of this study is to investigate the role of serum complement C1q as a potential biomarker for early diagnosis of CSVD in a sample of Egyptian patients. Patients and Methods 30 patients with CVSD and 20 healthy volunteers who were matched for age and sex were recruited. Serum complement C1q was determined by ELISA according to manufacturer instructions. Results Serum C1q levels were significantly higher in CVSD patients compared to healthy controls. On the other hand, serum C1q levels were not significantly correlated with clinical symptoms or radiological findings in this population. Conclusion Complement C1q may play a role in pathogenesis of incidental cerebral small vessel disease and warrants further studies.

Association between serum complements and kidney function in patients with diabetic kidney disease.

We aimed to explore the association between serum complements and kidney function of diabetic kidney disease (DKD) in Chinese patients. This is a retrospective study involving 2,441 participants. DKD was diagnosed according to the Kidney Disease: Improving Global Outcomes (KDIGO) categories. Participants were classified as stages G1-G5 by KDIGO glomerular filtration rate (GFR) categories. Effect sizes are expressed as odds ratio (OR) with 95% confidence interval (CI). After balancing age, gender, systolic blood pressure (SBP), hemoglobin A1c (HbA1C), serum triglyceride (TG), and urinary albumin-to-creatinine ratio (UACR) between the G2-G5 and control groups, per 0.1 g/L increment in serum complement C3 was significantly associated with a 27.8% reduced risk of DKD at G5 stage (OR, 95% CI, P: 0.722, 0.616-0.847, <0.001) relative to the G1 stage. Conversely, per 0.1 g/L increment in serum complement C4 was associated with an 83.0-177.6% increased risk of G2-G5 stage (P<0.001). Serum complement C1q was not statistically significant compared to controls at all stages prior to or after propensity score matching. Our results indicate that high concentrations of serum C4 were associated with the significantly elevated risk of kidney function deterioration across all stages, and reduced serum C3 levels with an increased risk of DKD stage G5.

Predictive value of soluble CD59 for poor 28-day neurological prognosis and all-cause mortality in patients after cardiopulmonary resuscitation: a prospective observatory study

BackgroundsCD59, as a soluble form of CD59, is observed in multiple types of body fluids and correlated with the cell damage after ischemia/reperfusion injury. This study aims to observe the dynamic changes of serum sCD59 in patients after restoration of spontaneous circulation (ROSC) and explore the association of serum sCD59 with neurological prognosis and all-cause mortality in patients after ROSC.MethodsA total of 68 patients after ROSC were prospectively recruited and divided into survivors (n = 23) and non-survivors (n = 45) groups on the basis of 28-day survival. Twenty healthy volunteers were enrolled as controls. Serum sCD59 and other serum complement components, including sC5b-9, C5a, C3a, C3b, C1q, MBL, Bb, and pro-inflammatory mediators tumor necrosis factor (TNF)-α, interleukin-6 (IL-6), neurological damage biomarkers neuron-specific enolase (NSE) and soluble protein 100β (S100β) were measured by enzyme linked immunosorbent assay on day 1, 3, and 7 after ROSC. Neurologic outcome was assessed using cerebral performance category scores, with poor neurologic outcome defined as 3–5 points.ResultsIn the first week after ROSC, serum levels of sCD59, sC5b-9, C5a, C3a, C3b, C1q, MBL, Bb, TNF-α, IL-6, NSE and S100β were significantly elevated in patients after ROSC compared to healthy volunteers, with a significant elevation in the non-survivors compared to survivors except serum C1q and MBL. Serum sCD59 levels were positively correlated with serum sC5b-9, TNF-α, IL-6, NSE, S100β, SOFA score and APACHE II score. Moreover, serum sCD59 on day 1, 3, and 7 after ROSC could be used for predicting poor 28-day neurological prognosis and all-cause mortality. Serum sCD59 on day 3 had highest AUCs for predicting poor 28-day neurological prognosis [0.862 (95% CI 0.678–0.960)] and 28-day all-cause mortality [0.891 (95% CI 0.769–0.962)]. In multivariate logistic regression analysis, the serum level of sCD59D1 was independently associated with poor 28-day neurological prognosis and all-cause mortality.ConclusionsThe elevated serum level of sCD59 was positively correlated with disease severity after ROSC. Moreover, serum sCD59 could have good predictive values for the poor 28-day neurological prognosis and all-cause mortality in patients after ROSC.

Association of serum complement C1q with cardiovascular outcomes among patients with acute coronary syndrome undergoing percutaneous coronary intervention.

To determine the association of serum complement C1q levels with cardiovascular outcomes among patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI), and evaluate the value of C1q modified by high-sensitivity C-reactive protein (hs-CRP) levels as an independent predictor. As a single-center prospective observational study, we analyzed 1701 patients who had received primary or elective PCI for ACS at Beijing Anzhen Hospital, Capital Medical University, Beijing, China between June 1, 2016 and November 30, 2017. The associations of C1q modified by hs-CRP with major adverse cardiovascular events (MACE) were determined in survival analysis. Patients with the lowest C1q tertile had the highest cumulative risk of MACE (log-rank P = 0.007). In fully adjusted Cox regression models, stratifying the total population according to hs-CRP dichotomy, C1q was significantly associated with MACE in patients with hs-CRP levels less than 2 mg/L but not in those with 2 mg/L or more (P interaction = 0.02). In patients with hs-CRP levels less than 2 mg/L, with the lowest C1q tertile as reference, the risk of MACE was reduced by 40.0% in the middle C1q tertile [hazard ratio (HR) = 0.600, 95% CI: 0.423-0.852, P = 0.004] and by 43.9% in the highest C1q tertile (HR = 0.561, 95% CI: 0.375-0.840, P = 0.005). Serum complement C1q is significantly associated with cardiovascular outcomes in patients with ACS undergoing PCI, only when hs-CRP levels are less than 2 mg/L. This finding implicates the usefulness of C1q for the risk stratification in ACS patients with reduced systemic inflammation.

The differences in serum C1q levels between first-episode patients with bipolar disorder and major depressive disorder

ObjectiveThis study aimed at exploring the changes of serum complement C1q levels in patients with Bipolar Disorder (BD) using a cross-sectional design, and the differences between Major Depressive Disorder (MDD) and BD. Moreover, the correlation between complement C1q and bech-rafaelsdn mania rating scales (BRMS) in patients with MDD and BD was assessed. MethodsSerum complement C1q levels were measured by ADVIA 2400 biochemical analyser in 104 patients with MDD, 71 patients with BD type I and 42 patients with BD type II diagnosed by Diagnostic and Statistical of Mental Disorder 5 (DSM-5). Then simple and multivariate linear regression analysis was conducted between the level of serum C1q and BRMS among patients with BD. ResultsThe serum complement C1q levels were higher in BD type I than BD type II (P < 0.001); Serum complement C1q levels were higher in MDD than BD type II (P < 0.001). We discovered that there was a positive correlation relationship between serum complement C1q levels and BRMS in BD type I (r = 0.756, P < 0.001). ConclusionWe confirmed that serum complement C1q levels were higher in patients with BD type II than in MDD patients. These current results support the view that the complement C1q may play an important role in the pathophysiology of BD. Serum complement C1q was strongly associated with BD and is worth investigating in future studies.

Serum complement C1q level is associated with left ventricular hypertrophy induced by coarctation of the aorta: A retrospective observational study

BackgroundThe complement system plays an important role in the development of left ventricular hypertrophy. Complement C1q is an initial component of the classical complement pathway and is related to many inflammatory diseases. We aimed to determine whether there was an association between serum complement C1q and left ventricular hypertrophy induced by coarctation of the aorta (CoA).MethodsBased on whether CoA was combined with a large ventricular septal defect (VSD) or patent ductus arteriosus (PDA), the patients were divided into a simple CoA group (n = 15) and a complex CoA group (n = 13). Meanwhile, we selected simple large VSD (n = 14) patients and normal children (n = 28) as the control group. The serum complement C1q level was compared using immunity transmission turbidity among different groups.ResultsThe preoperative content of C1q in the simple CoA group was significantly lower than that in the complex CoA group and normal group (96.97 ± 20.66 vs. 130.73 ± 35.78, 96.97 ± 20.66 vs. 156.21 ± 29.14, P < 0.05). There was no significant difference in the preoperative content of C1q between the complex CoA group and the large VSD group (P > 0.05). There was a negative correlation between the preoperative complement C1q content and the interventricular septal thickness and left ventricular posterior wall thickness (r = − 0.035, r = − 0.288, P < 0.05). The percentage of postoperative decrease in C1q in children with simple CoA or complex CoA was positively correlated with the time of cardiopulmonary bypass and aortic cross clamp, respectively (r = 0.797, r = 0.622, r = 0.898, r = 0.920, P < 0.05). There was no significant difference in the content of preoperative triglycerides (TG), total cholesterol (TCHO), high-density lipoprotein cholesterol (HDL-C) or low-density lipoprotein cholesterol (LDL-C) among the different groups (P > 0.05). In the simple CoA group and complex CoA group, the preoperative complement C1q, TG, TCHO, HDL-C and LDL-C levels were significantly higher than those after the operation (P < 0.05). There was no significant correlation between preoperative complement C1q and TG, TCHO, HDL-C or LDL-C (P > 0.05).ConclusionsComplement C1q has an inhibitory effect on the formation of left ventricular hypertrophy, which may not be mediated by regulating lipid metabolism. During cardiac surgery, complement C1q may have a protective effect against myocardial injury.

Abnormal lower expression of GPR183 in peripheral blood T and B cell subsets of systemic lupus erythematosus patients

G protein-coupled receptor 183 (GPR183) has been indicated to mediate the migration and localisation of immune cells in T cell-dependent antibody responses. Systemic lupus erythematosus (SLE) is a canonical autoimmune disease involving B cell-mediated tolerance destruction and excessive pathogenic autoantibody production, in which multiple GPCRs play a role. To date, there has been no systematic study regarding the expression of GPR183 in lymphocyte subsets of SLE patients. In this research, firstly, we observed the expression trends of GRP183 in various T and B cell subsets in human tonsil tissues. These lymphocyte subsets include CD4+, CD8+, naïve T, effector T, Tfh, activated Tfh, Th1, Th2, Th17, Treg, CD19+CD27-, CD19+CD27+, naïve B, germinal centre B, memory B, and plasma cells. Further, compared with healthy controls (HCs), GPR183 expression levels in above peripheral blood lymphocyte subsets of patients with SLE were reduced overall. The differential expression of GPR183 expression between inactive and active SLE patients indicates that GPR183 expression may be concerned with the disease activity of SLE. This was further confirmed through the strong negative correlation with SLEDAI score and positive correlation with serum complement protein C3, C4 and C1q levels. Further receiver operating characteristic (ROC) curve analysis revealed that GPR183 expression in circulating CD27-IgD+ B cells may be beneficial in distinguishing between inactive and active SLE patients. In addition, type I interferon stimulation could down-regulate the expression of GPR183 in peripheral blood T and B cell subsets. Aberrant expression of GPR183 may provide some novel insights into disease activity prediction and underlying pathogenesis of SLE.

Elevated Serum Complement C1q Levels After Traumatic Brain Injury [Letter

Elevated Serum Complement C1q Levels After Traumatic Brain Injury [Letter

Changes of Serum Complement C1q in Patients with Multiple Myeloma

To analyze the change of serum C1q in the course of multiple myeloma (MM) and its correlation with clinical characteristics. A total of 138 newly diagnosed MM patients in Zhongnan Hospital of Wuhan University from June 2016 to December 2019 were selected as research objects, during the same period 50 age-matched anemia patients, 50 lymphoma patients, 50 leukemia patients, and 50 myelodysplastic syndrome (MDS) patients were selected as control groups. All the patients met WHO disease classification, and were definitely diagnosed by pathology or bone marrow smear/biopsy. The changes of C1q between MM patients and control group, as well as in different therapeutic responses of MM patients before and after treatment were compared, also the difference of clinical characteristics among MM patients with different C1q level, so as to analyze risk factors which led to C1q decline. The average value of C1q in MM patients was (128.18±51.24) mg/L, which was significantly lower than control group (P<0.01). The levels of white blood cell, platelet (PLT), hemoglobin (Hb), serum calcium, albumin, lactate dehydrogenase (LDH) in newly diagnosed high C1q group were significantly higher than those in low C1q group (P<0.05). Logistic analysis showed that the levels of PLT, Hb, albumin, and LDH in newly diagnosed high C1q group were higher than those in low C1q group (r=0.248, r=0.394, r=0.405, r=0.295). After treatment, the levels of C1q in MM patients with complete remission and very good partial remission were significantly higher than before treatment (P<0.05), while those with partial remission and stable disease also increased but not significantly (P>0.05). The C1q level in MM patients is significantly lower than that in patients with other hematologic system diseases, and it increases with the remission of the disease after treatment.

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

ObjectiveComplement 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).MethodsIn 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.ResultsTBI 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).ConclusionElevated serum C1q levels are closely correlated with traumatic severity and independently predicted the risk of long-term poor prognosis after TBI.

Association of Serum Complement C1q and C3 Level with Age-Related Macular Degeneration in Women

PurposeTo investigate the association between serum complement components and age-related macular degeneration (AMD).Patients and MethodsA total of 118 AMD patients and age- and sex-matched 106 control subjects were included. Demographic data and the level of serum complement component (C)1q, C3 and C4 were evaluated. Based on sex, the subjects were stratified into male and female subgroups.ResultsThe level of C1q (226.31±45.33mg/dL) was significantly higher and C3 (121.14±15.76mg/dL) was significantly lower than that in control group (200.03±38.54mg/dL) (128.42±19.81mg/dL) in the female AMD patients (p = 0.005, p = 0.045). Logistic regression showed that increased C1q (OR = 1.132, p = 0.016) and decreased C3 (OR = 0.960, p = 0.048) were independent risk factors for female AMD patients. No statistical significance was observed in the male.ConclusionIncreased C1q and decreased C3 were associated with increased risk of AMD, suggesting that the complement classical pathway probably be involved in AMD, especially in female.

Updates in diabetic neuropathy: A call for new diagnostic and treatment approaches.

Diabetic polyneuropathy (DPN) is a serious complication of both type 1 and type 2 diabetes. The major clinical manifestations of DPN are neuropathic pain, diabetic foot (which is associated with ulcers, gangrene, and amputation), and autonomic neuropathy. Diabetic sensorimotor peripheral neuropathy (DSPN) is the most common form of DPN and affects approximately 50% of people with type 1 or 2 diabetes during their lifetime (1) . Despite its major clinical impact, DPN remains underdiagnosed and undertreated. To reduce the burdens of DPN, there is an urgent need to develop both novel diagnostic procedures that enable to improve the early detection of the disease and new treatments that address multiple mechanistic pathways (Figure) (2) .

Serum Level of Complement C1q is Associated with Contrast-Associated Acute Kidney Injury in Patients Undergoing Emergency Percutaneous Coronary Intervention.

BackgroundAs an inflammatory factor, complement C1q is related to the prevalence and progression of atherosclerosis; however, in patients undergoing emergency percutaneous coronary intervention (PCI), it is unclear whether C1q is related to the prevalence of contrast-associated acute kidney injury (CA-AKI).MethodsFrom November 2018 to March 2021, 1182 patients who underwent emergency PCI were continuously recruited. Patients were divided into CA-AKI group (n = 234) and non-CA-AKI group (n = 948). CA-AKI was defined as an increase in serum creatinine from the baseline level (≥25% or ≥0.5 mg/dL) 48–72 hours after contrast exposure. All subjects were tested for serum C1q levels when they were admitted to the hospital.ResultsAmong the 1182 patients undergoing emergency PCI, 234 patients (19.80%) developed CA-AKI. The level of preoperative serum complement C1q in the CA-AKI group was significantly higher than that in the non-CA-AKI group. Logistic regression and restricted cubic spline analyses showed that the incidence of CA-AKI was positively associated with the serum C1q level pre-PCI. Univariate and multivariate logistic regression analyses showed that C1q was an independent predictor of whether CA-AKI occurred after emergency PCI. The area under the curve (AUC) of the C1q was 0.703 [95% confidence interval (CI) 0.667–0.739] in patients receiving emergency PCI. CA-AKI model included the following three predictors: C1q, eGFR, and IABP use. The AUC of forecast probability was 0.718 [95% CI 0.682–0.754].ConclusionIn patients receiving emergency PCI procedure, a high C1q level before PCI is associated with the increased risk of CA-AKI.

Serum Complement C1q Activity Is Associated With Obstructive Coronary Artery Disease.

Background: Complement C1q plays a dual role in the atherosclerosis. Previous studies showed inconsistent results about the association of serum C1q levels and coronary artery disease (CAD). Here, we explored the associations of serum C1q activity with CAD, coronary stenosis severity, cardiovascular biomarkers, and 1-year restenosis after coronary artery revascularization.Methods: We enrolled 956 CAD patients and 677 controls to evaluate the associations of serum complement C1q activity to the presence and severity of obstructive CAD and non-obstructive CAD. Serum C1q activity and the concentrations of laboratory markers were measured in all subjects. All the data were analyzed using SPSS22.0 software.Results: Serum C1q activity in Obstructive CAD and Non-Obstructive CAD groups was significantly higher than the control group (195.52 ± 48.31 kU/L and 195.42 ± 51.25 kU/L vs. 183.44 ± 31.75 kU/L, P < 0.05). Greater C1q activity was significantly correlated with higher total cholesterol (TC) and triglyceride (TG) levels. C1q activity was associated with an increased Odds Ratio (OR) of CAD (OR = 1.322, 95% CI 1.168–1.496, P < 0.05) and 1-year restenosis after revascularization (the highest OR = 3.544, 95% CI 1.089–12.702, P < 0.05). Complement C1q activity was not correlated with Gensini score in the Obstructive CAD group after adjustment for confounders. C1q activity has low value in predicting the incidence of CAD.Conclusion: Serum complement C1q activity is associated with obstructive CAD.

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.

Relationships between diabetic nephropathy and insulin resistance, inflammation, Trx, Txnip, CysC and serum complement levels.

To investigate the relationships between diabetic nephropathy (DN) and insulin resistance, inflammation, thioredoxin (Trx), thioredoxin-interacting protein (Txnip), Cystatin C (CysC) and serum complement levels. A total of 119 patients with type 2 diabetes mellitus (T2DM) treated in the Endocrinology Department of our hospital from January 2017 to December 2017 were enrolled as the experiment group, while 30 healthy volunteers were selected as the control group. The expression levels of inflammatory factors, Trx, Txnip, CysC and serum complements in every subject were detected. In addition, the type 2 diabetic nephropathy rat model was established via high-fat diet and injection of low-dose streptozotocin. Blood glucose, insulin resistance indexes and 24h-urinary albumin excretion were measured, and the histomorphological characteristics of the kidney in animals were observed. In clinical subjects, Trx level was notably lower in the simple DM group, early DN group and clinical DN group in comparison with that in the control group. The levels of Txnip and CysC in the simple DM group, early DN group and clinical DN group were remarkably higher than those in the control group. Moreover, the expression levels of TNF-α and IL-6 in the clinical DN group were significantly elevated compared with those in the simple DM group and early DN group. In addition, C1q expression in the clinical DN group was higher than that in the simple DM group and early DN group. In model rats, HOMA-IR was distinctly higher in the DM group and DN group than that in the control group. The ratio of kidney weight to body weight (KW/BW) was evidently higher in the DN group in comparison with that in the control group and DM group. Insulin resistance, inflammatory factors, and levels of Trx, Txnip, CysC and serum complement C1q are related to the progression of DM.

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

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

Increased serum levels of complement C1q in major depressive disorder

BackgroundThe complement system is involved in multiple biological processes including inflammation, synaptic pruning, and apoptosis. However, it is not well understood whether peripheral complement C1q levels are altered in major depressive disorder (MDD) patients. ObjectiveThis study aimed at assessing serum levels of complement C1q in MDD patients using a cross-sectional, case-control design. Also, the correlations between complement C1q and inflammation and lipid profile in patients with MDD were also assessed. MethodsSerum complement C1q levels were measured by ADVIA 2400 biochemical analyzer in 160 patients with MDD diagnosed using International Classification of Diseases-10 criteria (ICD-10) and were compared with those of 159 healthy controls between January 2017 to May 2019. Then correlation analysis was carried out between the level of serum complement C1q among MDD patients with inflammation and lipid profile. ResultsSerum complement C1q levels were higher in MDD patients than in controls (P < .0001) and the difference between the two groups was small (r = 0.239 [0.128 to 0.350]). We found that serum complement C1q concentrations was positively correlated with HAMD-24 score (r = 0.234, P = .003) and log hs-CRP (r = 0.334, P < .001). ConclusionWe found serum complement C1q levels were significantly higher in MDD patients than in controls. The current results suggest that the dysfunction of complement C1q may be involved in the pathophysiology of MDD.

Serum complement C1q level is associated with acute coronary syndrome

Background and objectivesThe complement system plays an important role in the development of acute coronary syndrome (ACS). Complement C1q is an important initial component of the classical complement pathway and closely related to many chronic inflammatory diseases, including atherosclerosis (AS). We aimed to determine whether there was association between serum complement C1q and the severity of coronary stenosis. Subjects and methods320 patients who underwent coronary arteriography (CAG) were stratified into non-ACS group (control group, n = 74), unstable angina group (UA group, n = 197) and acute myocardial infarction group (AMI group, n = 49) according to the severity of coronary stenosis and clinical manifestations. The severity of coronary stenosis was represented in Gensini score, and serum complement C1q level was compared using immunity transmission turbidity among three groups. ResultsThe level of complement C1q in AMI group was lower significantly than control group and UA group (P < 0.05), but there was no correlation between serum complement C1q and Gensini score (β=-0.086, P = 0.125). In nitrate-taking patients, serum complement C1q had a negative association with Gensini score (r=-0.275, P = 0.001), and in non-smokers, there was also a negative correlation (β=-0.159, P = 0.036). After calibrating smoking, drinking or statins, the serum complement C1q levels of control group, UA group and AMI group decreased in sequence (P < 0.05). Logistic regression analysis showed that the decreasing of serum complement C1q was an unfavorable factor for acute myocardial infarction (OR=0.984, 95 %CI=0.972∼0.997, P = 0.015) and for ACS (OR=0.984, 95 %CI=0.971∼0.984, P = 0.025) in drinking patients. Regrettably, ROC curve suggested that the accuracy in diagnosing coronary atherosclerotic heart disease by serum complement C1q was low (AUC=0.568, 95 %CI= 0.492-0.644, P = 0.076, sensitivity 73.6 %, specificity 58.1 %). ConclusionSerum complement C1q in ACS patients, in particular AMI patients, showed lower level. This finding suggests further decrease of complement C1q level in ACS patients may be a contributory factor to instability or rupture of atherosclerotic plaques. Combined with other clinical indicators, it can be helpful to predict the risk and severity of coronary stenosis.

Is serum complement C1q related to major depressive disorder?

Background:Major depressive disorder (MDD) has a high global incidence. While the pathogenesis of depression remains unknown, accumulating evidence has implicated inflammatory changes.Aim:The aim of the study is to compare the serum complement C1q levels in patients with MDD and healthy controls.Setting and Design:The design was a case–control study.Materials and Methods:Blood samples were collected from the patients with MDD and healthy controls to assess the serum C1q levels using an immunotransmission turbidimetric method.Statistical Analysis:Differences in complement C1q levels between patients with MDD and the controls, as well as between sexes among patients with MDD and the controls, were assessed using Mann–Whitney U-test. Spearman correlations were obtained between complement C1q levels and age.Results:In total, 1016 participants (508 MDD and 508 controls) were recruited. Differences in the sex ratio (male/female among controls, 181/327; and MDD, 178/330) and age (controls, 47.0 ± 14.9 years; MDD, 46.5 ± 16.5 years) were not significant. The C1q level in the patients with MDD was significantly higher than that in the healthy controls (P < 0.05). In the MDD group, C1q level correlated significantly with age.Conclusion:Elevation of the serum complement C1q levels in MDD may support the use of C1q as a potential biomarker for diagnosing depression, but further research is needed.