In a previous work reserachers have provided evolutionary and functional evidence for positive natural selection at the human CD5 immune receptor. In the present work,they further analyzed the functional relevance of non-synonymous CD5 polymorphisms and found that the ancestral haplotype form of the CD5 receptor (Pro224-Ala471) confers lymphocyte hyper-responsiveness to TCR/CD3 cross-linking and is associated with nephritis in Systemic Lupus Erythematosus   (SLE) lupus. Overall these findings provide a nice case of how an adaptation that probably conferred resistance to pathogens in the past influences inflammatory disease today. 

Ref. Art. Cenit MC, et al. 2014. Analysis of Ancestral and Functionally Relevant CD5 Variants in Systemic Lupus Erythematosus Patients. PLoS ONE 9(11): e113090. doi:10.1371/journal.pone.0113090

This work has been led by researchers at Instituto de Parasitologıía y Biomedicina López-Neyra and Institut d'Investigacions Biomediques August Pi i Sunyer in collaboration with IBE researchers and several other centres in Spain.