Polymyalgia rheumatica

With polymyalgia rheumatica, “poly-“ means many, “mya-” means muscles, and “-algia” means pain.

“Rheumatica” comes from rheumatism, which broadly refers to conditions that affect the joints and connective tissue.

So, polymyalgia rheumatica is a disorder that causes muscle pain and joint stiffness.

It is considered to be an immune- mediated disease, meaning that the immune system attacks our own body.

It is important to note that although “myalgia” means muscle pain, the muscles are usually spared and it's the tissue around the joints that mostly gets inflamed.

Normally, the cells of the immune system are always hanging around, ready and excited to spot and fight against anything foreign that could cause harm inside the body.

One particular type of immune cell - the dendritic cell - is a type of antigen-presenting cell, meaning that it grabs a pathogen for example a bacteria, destroys it, and presents a part of that bacteria, called an antigen, to other immune cells.

Dendritic cells take their name from the fact that they have branch like arms called dendrites which help them grab antigen.

Dendritic cells take their captured antigen and move over to a nearby lymph node, where they present the antigen to a helper T-cell.

Dendritic cells “present” the antigen on a protein called a major histocompatibility complex, or MHC, class II molecule which is on their cell surface.

MHC class II molecules are like a serving platter, which hold the antigen as it gets presented to the helper T-cells.

Once these antigens are recognized as foreign, T-helper cells get activated and start secreting a lot of proinflammatory cytokines, or signalling molecules, that recruit more immune cells, such as macrophages, to the site of inflammation.

At the same time, other cytokines, called interleukins, trigger B-cells to secrete antibodies against the targeted antigens.