As the home of the stem cells that produce blood and immune system cells, bone marrow is a complicated tissue for people with lupus.
Bones are vital, hardworking parts of the body – they protect organs, provide structure, and enable all forms of movement, large or small. People with lupus often have issues with these important structures.
Systemic lupus erythematosus (SLE,) has the capacity to affect any organ in the body, but it is most well-known for its affects on the joints, the lubricated, soft areas of cartilage in between different bones that allow limbs to bend and move. SLE attacks the joints, causing them to become inflamed, swollen, and damaged, locking up the limbs and making it difficult and painful to move. When the joints are attacked, the bones are often not spared, and the ends of the bones can often be directly damaged by lupus.
Lupus medications, such as glucocorticoids, are notorious for causing bone loss. Osteoporosis is the general catch-all term for bone that has either been thinned and weakened or has been encouraged by disease to grow in ways that make it weaker – thicker bone in the wrong places can be just as structurally unsound as less bone! However, people with lupus usually experience bone loss and more fragile bones.
Lupus itself causes pain and fatigue, which leads to inactivity, a contributor to osteoporosis. You can read more about fatigue here. Because the weakened bone from osteoporosis might make it risky to do certain activities, this creates a vicious cycle of inactivity, which can make all lupus symptoms worse – including the weakened bones!
So, lupus does have an effect on the bones, but what about the bone marrow inside many of the larger bones of the body? And how is this bone marrow important for people with lupus?