biostudies-literatureVeuskens BRJSanquin Research FundEuropean Union's Horizon 2020 research and innovation programme10669https://www.ebi.ac.uk/biostudies/studies/S-EPMC11950314biostudies-literatureUnknown15(1)Factor H-related (FHR) protein 1 and 2 form dimers resulting in FHR-1 and -2 homodimers, and FHR-1/2 heterodimers. Dimerization is hypothesized to further increase their antagonistic function with complement regulator factor H (FH). So far, only FHR-1 homodimers and FHR-1/2 heterodimers could be quantified in a direct way. With the reported genetic associations between CFHR2 and complement-related diseases such as age related macular degeneration and C3-glomerulopathy, direct assessment of FHR-2/2 levels determining the dimer distribution of FHR-1 and -2 is needed to further elucidate their role within complement regulation. Therefore, novel in-house generated FHR-2 antibodies were used to develop a specific ELISA to enable direct quantification of FHR-2 homodimers. Allowing for the first Scientific reportsFactor H-related 2 levels dictate FHR dimer composition.PMC11950314899163SRF-YIA-23-06Brouwer MCKeijzer NCHvan Mierlo GVeuskens BRJHoogenboezem MPouw RBGeissler Jvan Leeuwen KDerlagen MKuijpers TWfalseFactor H-related 2 levels dictate FHR dimer composition.Factor H-related (FHR) protein 1 and 2 form dimers resulting in FHR-1 and -2 homodimers, and FHR-1/2 heterodimers. Dimerization is hypothesized to further increase their antagonistic function with complement regulator factor H (FH). So far, only FHR-1 homodimers and FHR-1/2 heterodimers could be quantified in a direct way. With the reported genetic associations between CFHR2 and complement-related diseases such as age related macular degeneration and C3-glomerulopathy, direct assessment of FHR-2/2 levels determining the dimer distribution of FHR-1 and -2 is needed to further elucidate their role within complement regulation. Therefore, novel in-house generated FHR-2 antibodies were used to develop a specific ELISA to enable direct quantification of FHR-2 homodimers. Allowing for the first 2025-01-01T00:00:00Z2025 Mar2026-06-03T02:35:31.689Z2025-07-09T03:04:32.341ZS-EPMC119503144014849110.1038/s41598-025-94064-4