Early Pathophysiology Of RA Flashcards
What causes RA
Unknown
Possible RA triggers
Infection
Smoking
Obesity
Stress
Female hormones
Pregnancy
Difference between seropositive and seronegative RA
seropositive has anti citrullinated protein antibodies
Seronegative has no ACPAs
Same clinical presentation
Is seropositive or seronegative RA harder to control and which is more common
Seropositive for both
Are smoking, bacterial infections, HLA-DRB1, and PTPN22 risk factors for seropositive or seronegative RA
Seropositive
Are cytomegalovirus, EBV, IRF5, and C type lectins risk factors for seropositive or seronegative RA
Seronegative
Does seropositive or seronegative have higher disease activity, more CV complications, more joint destruction, and higher death rate
Seropositive
What process by neutrophils is involved in RA
NETosis
NETosis
Neutrophils release NETs - lattice of NET fibres containing enzymes, anti microbial peptides, and ion chelations to kill microorganisms
Suicidal NETosis
NETosis where the cell is ruptured and killed to release the NET
Which enzyme citrullinates arginine to citroline
Protein arginine deaminase 4 PAD4
What can cause neutrophils to undergo NETosis in RA when no bacteria are present
Autoantibodies
Rheumatoid factor
IgM to Fc portion of IgG
What processes require PAD4 mediated citrullination of histones
NET formation
Bacterial clearance
Carbamylation
Converts lysine into homocitrullines by reaction with cyanate