Unfortunately videos pem me too fast now, I can only read
A shame as I was going to suggest Dr Been's recently updated video series on immunology. Perhaps you might be able to listen to them, though the strength of his style is with the approachable cartoons he draws. He speaks softly and slowly which may well be appreciated by others here interested in this very complex subject. He's been making videos on many medical subjects for over 11 years. Here's the link to all of his lectures on immunology over the years.
The recent ones are —
Your Immune System (Part 1)
Your Immune System (Part 2)
It is a lifetime's learning getting to see all the ways antibodies can cause trouble.
I've taken the liberty of quoting Prof's earlier answer, and added some hopefully relevant Wikipedia links for us all.
Prof JE wrote earlier —
I would need a whole immunology textbook and the ones out there don't always make the simple things clear.
Antibodies bind antigen and can simply block its function without generating any inflammation.
To generate inflammation antibodies need to bind either complement or macrophage Fc receptors. They will do either or both if several antibody molecules are brought together - either bringing arms of complement C1q together or cell surface Fc receptors together.
Binding complement in the circulation is anti-inflammatory because the activated complement binds clearing receptors on red cells (CR1). Binding complement outside circulation releases C3a and C5a (chemotaxis) and binds to receptor CR3 leading to cell activation. Binding of Fc receptors leads to cytokine release - TNF and IL-1 - which produces much more destructive inflammation than complement.
The antibodies in RA are directed to immunoglobulin itself (Fc portion) and called rheumatoid factors. There are also antibodies to citrullinated peptide sites. The detail is very complicated but in simple terms the autoantibodies in RA are small enough to evade clearance by complement receptor 1 but just big enough to activate cytokines through Fc receptor IIIa. That receptor is preferentially expressed in joint lining - which is why it is a disease mostly of joints. Complexes of similar size contribute to lupus, which also often includes arthritis.
The complexes most typical of lupus are large. They cause damage because the clearing receptor CR1 is [not] operating effectively. That means that complexes can get big enough in the circulation to silt up in the kidney and brain with nephritis and encephalitis (never seen in RA where CR1 is working properly).