What can I say? It's complicated.
Endometriosis is an inflammatory disease, so a lot of people have questions about blood tests that look at inflammation. Let's look at what inflammatory markers are and specifically at CRP:
"Serum proteins that are produced in response to inflammation can be referred to as inflammatory markers. These proteins are mainly produced by the liver in response to stress and can also be called acute phase reactants. Pro-inflammatory cytokines such as IL-1, IL-6, and TNF-alpha induce synthesis of some acute phase reactants that include CRP, fibrinogen and haptoglobin. Other proteins, like albumin, are not sensitive to inflammatory cytokines for increased synthesis; instead chronic stress (inflammation) results in a lower synthesis rate with resultant decreased serum concentrations. The inflammatory markers are not diagnostic of inflammation, but reflect abnormalities that are seen in autoimmune diseases, infections, malignancies and other illnesses.
C-reactive protein (CRP)
So what does this have to do with endometriosis?
Remember, all these tests might be a mere indication of endometriosis, but they are very nonspecific. The only way to accurately diagnose endometriosis is through surgery.
Mast cells:"Mast cells may contribute to the development of pain and hyperalgesia in endometriosis
The presence of increased activated and degranulating mast cells in deeply infiltrating endometriosis, which are the most painful lesions, and the close histological relationship between mast cells and nerves strongly suggest that mast cells could contribute to the development of pain and hyperalgesia in endometriosis, possibly by a direct effect on nerve structures.
Researchers set out to detect and quantify mast cells in peritoneal, ovarian, and deep infiltrating endometriosis and to study the relationship between mast cells and nerves in endometriosis.Excision of endometriosis from different anatomical locations was undertaken in 69 women, who were undergoing laparoscopic excision of endometriosis for pain. Thirty-seven biopsies of normal tissue were obtained from women without endometriosis.
The women with deeply infiltrating lesions had significantly higher preoperative pain scores than women with peritoneal or ovarian endometriosis. Mast cells and degranulating mast cells are significantly more abundant in endometriotic lesions than in non-affected tissues. Deep infiltrating lesions show a significantly higher number of mast cells, activated mast cells, and mast cells located <25 mum from nerves than peritoneal and ovarian lesions. The authors found significantly more degranulating mast cells in deep infiltrating lesions than in peritoneal lesions.