Q. We heard in class today that steroids are used for autoimmune diseases, and I’ve heard this before but never understood why. What is it about steroids that make them effective as immunosuppressants?
A. There are lots of mechanisms by which steroids dampen the immune response. Here are a few of them:
1. Suppression of T cells. Steroids interfere with production of cytokines (like interleukins), which are critical in the proliferation and interaction of T cells.
2. Suppression of B cells. Steroids interfere with the binding of interleukins to B cells, which means that the B cells have a hard time proliferating and making antibodies.
3. Suppression of neutrophils. Steroids inhibit just about everything that neutrophils do: adhesion, chemotaxis, phagocytosis, and the release of toxic substances.
4. Suppression of macrophages. Steroids down-regulate the expression of Fc receptors on macrophages – so macrophages are less able to phagocytose opsonized things.
5. Diminished production of prostaglandins and leukotrienes. Steroids inhibit cyclooxygenase and phospholipase A2, which decreases the production of pro-inflammatory arachadonic acid metabolites.
Steroids are used in a ton of different immune and inflammatory disorders, like asthma, vasculitis, arthritis, gout, multiple sclerosis, sarcoidosis, alopecia areata…the list goes on and on.
- Sandeep Jain said As always, fantastic explanation! The delay in maturation time with decreasing Hgb is good to know!
- Baraniko Eromanga said Thanks for discussing this, it’s confusing me for long time, now I understand the differences.
- Kristine said Thanks, Raffi. No – the concept of shift reticulocytes is not the same as polychromasia. Polyc...
- Raffi said Thanks for the post. By chance, is the “shift reticulocyte” the same as polychromasia? I...
- vetstudent said u make things a lot of easier! tq
- Kristine said Sure – you just multiply the percentages by the total white blood cell count. For example: the...
- Qi said Thank you so much for this simple and clear explanation!You used magic to make a complicate term, my...
- thelma nsamya said Thank you so much for the path bites
- Michale said Is there anyone who knows how to covert % reference ranges to 10E 9/L for Differentials (ie. Neutrop...
- Sundar said From which cell does desmoid tumor arises ? Is it fibroblast ?
- alexandra said Hi! I was wondering if you could explain seronegative lupus. Or how come some people might have SLE,...
- Heba El-Zawawi said It’s just great ! Keep going and GOOD LUCK!