Complement cascade activation results in the formation of complement split products C 3 a, C 4 a, and C 5 a. 4 These proteins, referred to as anaphylatoxins, facilitate the phagocytosis of immune complexes, viral particles, toxic cell debris and apoptotic corpses.

2021年7月6日 · WHAT DOES IT MEAN IF YOUR COMPLEMENT C4A RESULT IS TOO LOW? Lower-than-normal complement C4 values could indicate: – bacterial infections. – hepatitis. – malnutrition. – rejection of a kidney transplant. – systemic lupus erythematosus, which is an autoimmune disease affecting the skin, joints, kidneys, and other organs.

The testing for C4a can help determine if a deficiency or abnormality is a contributing factor to increased infections or increased autoimmune activity. The measurement can also be used to monitor autoimmune disorders. C4a, in conjunction with C3a, may be useful markers in acute and chronic Lyme disease. Reference Ranges for Complement C4a:

2025年3月22日 · Track Air China (CA) #484 flight from Kuala Lumpur Int'l to Chengdu Tianfu Int'l Flight status, tracking, and historical data for Air China 484 (CA484/CCA484) including scheduled, estimated, and actual departure and arrival times.

2024年8月1日 · Complement C4 protein is expressed as two isotypes, C4A and C4B, which are encoded by the C4 genes (C4A or C4B gene), and share >99% sequence identities. The difference lies in four isotype-specific amino acid substitutions at amino acid positions 1120–1025 (C4A: 1120 PCPVLD 1125; C4B: 1120 LSPVIH 1125).

2019年8月6日 · Complement component 4 (C4) gene copy number (GCN) affects the susceptibility to systemic lupus erythematosus (SLE) in different populations, however the possible phenotype significance remains to be determined. This study aimed to associate C4A, C4B and total C4 GCN and SLE, focusing on the clinical phenotype and disease progression.

We elucidated the gene copy number (GCN) variations of total C4, C4A and C4B, long and short genes in 1644 Caucasian patients with IIM, plus 3526 matched healthy controls using real-time PCR or Southern blot analyses. Plasma complement levels were determined by single radial immunodiffusion.

应急和回归分析显示，在 c4a 缺乏症患者中，hla-dr3 的存在作为 iim 的危险因素变得无关紧要，除了包涵体肌炎 （ibm），其中 98.2% 的 hla-dr3 为 or，or 为 11.02 （1.44-84.4）。

C4a is a putative agonist for protease-activated receptors (PAR)1 and PAR4. Screening of the gpcrMAX panel in agonist mode reveals that PAR1 and PAR4 meet the selective criteria as putative targets for C4a. Dash line represents 30% of activation. The data represent the mean ± SD of duplicate samples.

Our study provides the first clinical evidence that the protamine-heparin complex activates complement via the classic (C4a) pathway. The hemodynamic effects of protamine after CPB may be related to complement activation.