Association of complement components with risk of colorectal cancer:A systematic review and meta-analysis

BACKGROUND Complement components could contribute to the tumor microenvironment and the systemic immune response.Nevertheless,their role in colorectal cancer(CRC)remains a contentious subject.AIM To elucidate the relationship between complement components and CRC risk and clinical characteristics.METHODS Searches were conducted in PubMed,the Cochrane Library,and the China National Knowledge Infrastructure database until June 1,2023.We included cohort studies encompassing participants aged≥18 years,investigating the association between complement components and CRC.The studies were of moderate quality or above,as determined by the Agency for Healthcare Research and Quality.The meta-analysis employed fixed-effects or random-effects models based on the I^(2)test,utilizing risk ratio(RR)and their corresponding 95%confidence interval(CI)for outcomes.Sensitivity and subgroup analyses were performed to validate the robustness of the collective estimates and identify the source of heterogeneity.RESULTS Data from 15 studies,comprising 1631 participants that met the inclusion criteria,were included in the meta-analysis.Our findings indicated that protein levels of cluster of differentiation 46(CD46)(RR=3.66,95%CI:1.75-7.64,P<0.001),CD59(RR=2.86,95%CI:1.36-6.01,P=0.005),and component 1(C1)(RR=5.88,95%CI:1.75-19.73,P=0.004)and serum levels of C3(standardized mean difference=1.82,95%CI:0.06-3.58,P=0.040)were significantly elevated in patients with CRC compared to healthy controls.Strong expression of CD55 or CD59 was associated with a higher incidence of lymph node metastasis,whereas strong CD46 expression correlated with a higher incidence of tumor differentiation compared to low CD46 expression(P<0.05 for all).Although specific pooled results demonstrated notable heterogeneity,subgroup analyses pointed to regional differences as the primary source of inconsistency among the studies.CONCLUSION Our analysis underscores that increased levels of specific complement components are associated with a heightened risk of CRC,emphasizing the potential significance of monitoring elevated complement component levels.

Complement Gene Mutation and Ehlers-Danlos Syndrome

Background: Dental complications of Ehlers-Danlos syndrome (EDS) include periodontitis with gum fragility and inflammation, enamel hypoplasia with frequent caries, high palate with dental crowding, TMJ instability, sutural dehiscence or scarring, and insensitivity to anesthetics. Objective: Determine if EDS dental complications always define a specific type and genetic cause or if they can arise as a general consequence of altered inflammatory response in EDS. Method: We compared findings of a 58-year-old female with complement component 1R (C1R) gene mutation (c.1553A > T, p.Asp518Val) found by whole exome sequencing to 43 patients with C1R gene mutations ascertained because of periodontal disease and to 710 EDS patients conventially ascertained because of joint and skin laxity. Result: Female patients ascertained as periodontal EDS showed the expected higher frequency of periodontitis (96% versus 14%) but had similar frequencies of hypermobility (81% versus 90%) and some skin findings (84% versus 92% with skin fragility) as the general group and our female patient who shared their C1R gene change. Her oromandibular bone loss rather than gum disease may reflect the more carboxy-terminal position of her C1R gene mutation compared to those in the patients identified as periodontal EDS. Conclusion: While mutation of the C1R gene may predict more frequent periodontal, skin, and vascular complications, focus on an articulo-autonomic dysplasia process that includes mast-cell activation and altered inflammatory response rather than extreme EDS types will help dentists and other subspecialists identify all EDS patients and anticipate their frequent oral manifestations.

Low activity of complement in the cerebrospinal fluid of the patients with various prion diseases

Background:The aim of this study was to analyze the state of activity and levels of complement in the cerebrospinal fluid(CSF)of patients with various prion diseases(PrDs).Findings:The proteomic data emphasized the levels of 20 known complement components found in the CSF of the sCJD panel that were lower than those found in the non-PrD panel.50%of the complement hemolytic activity(CH50)assays revealed significantly lower activity of complement in the CSF of the sCJD panel.The decreased levels of three key complement subunits,C3a/α,C4β,and C9 in the CSF of the sCJD panel were verified by Western blots.Furthermore,the CH50 values in the CSF of 136 sCJD,39 gCJD,22 FFI and 145 non-CJD patients were individually tested.Compared with the control of non-PrD,the CH50 value in the CSF specimens of various PrDs,especially in three subtypes of inherited PrDs,were significantly lower.Relationship analysis identified that the CH50 activity in the CSF was negatively associated with the protein 14–3–3 positive in the CSF.Conclusion:These results indicate a silent complement system in the CSF of PrD patients.