Guest guest Posted May 18, 2002 Report Share Posted May 18, 2002 Speaking of this theory, I believe they have shown that long term zithromax use prevents heart disease due to a similar reasoning. > > Immunology is a large and complicated area of medicine that > > interrelates with many other areas. So it's not surprising that a > > number of immune-mediate (where the immune system contributes to > the > > disease) and infectious (where the immune system helps fight an > anti- > > microbial invasion) disorders were brought up under the immunology > > umbrella. I think we're more likely to understand rosacea by > > understanding immune-mediated activity rather than post- infectious > > conditions, but I'll tell you what I know about both in relation to > > local inflammation conditions like rosacea. > > > > Regarding immune-mediated, one type is autoimmune disorders. > > Autoimmunity is an immune response directed against an antigen > within > > the body. It is similar to an allergy, which is also an immune > > response, but in allergies the antigen is foreign to the body and > an > > allergy only involves part of the immune system, the T-cells or B- > > cells. One common misunderstanding and a key point: naturally > > occurring autoantibodies are common in all healthy people, so the > > mere presence of certain autoantibodies does not mean the person is > > sick or has a disease. Even if a condition is diagnosed from blood > > tests, it doesn't establish a cause-and-effect relationship, since > > the autoantibodies may be the result, not the cause, of the disease > > process. > > > > I don't believe rosacea is an autoimmune disorder like some types > of > > thyroid disease, multiple sclerosis, or lupus but it seems to be > > associated with other autoimmune disorders. The reason for the > > association is not clear, but I think it's an important association > > because it brings rosacea into the large family of immune- mediated > > disorders. > > > > Again regarding immune-mediated disorders, a large number of > > compounds in the body stimulate or inhibit immune reactions. One > > important group, cytokines, are proteins that help cells > communicate > > with one another and also sometimes regulate the immune system. A > > complex cytokine network is involved in normal immune function, and > > this network is comprised of positive and negative feedback loops > > that enhance or suppress the immune (in this case, frequently > > inflammatory) response. Many immune-mediated diseases (especially > > connective tissue/rheumatic diseases) involve the abnormal > regulation > > of cytokines. Understanding how cytokines interact is a hot area > for > > reseach, and since they are often related to local inflammation may > > ultimately prove helpful to rosaceans. > > > > In particular, cytokines are in large part responsible for > regulating > > the production of groups of small molecule mediators of > inflammation, > > such as prostaglandins and leukotrienes. Understanding these small > > immune-mediator molecules and how they relate with cytokinesis is > > also a very active area of research. For example, we already know > > that manipulation of prostaglandins are loosely associated with > > exacerbations and remissions in some people's rosacea; for example, > > it may be one of the mechanisms through which hormones affect > rosacea > > (although I would bet there are others). > > > > There are also interactions between the immune system and the > > neuropeptides such as NO and CRPG and all the rest that play a role > > in vasodilation and pain perception. So there are ways to tie in > the > > vascular and pain components of rosacea, and research in those > areas > > may prove helpful as well. > > > > Someone brought up scleroderma, and the unfortunate death of their > > parent and concerns about having the condition themselves. > > Scleroderma does show patterns of inheritance but in a very > > complicated manner. Essentially, scleroderma is a multi-system > > disorder involving immune activation, vascular damage, and > excessive > > synthesis of collagen. The cause of scleroderma seems to involve > the > > interplay between early immunological events and vascular changes, > > inducing a population of activated fibrogenic fibroblasts that > > produce the characteristic skin and inner organ changes. It's > > enticing to speculate whether there are similar immunologic events > in > > rosacea, but they are certainly not the same vascular changes or > skin > > changes, and rosacea is not associated with inner organ changes, so > > it's not that close a fit. > > > > Raynaud's phenomenon is associated with scleroderma and other > > connective tissue diseases, occlusive vascular disease, and some > drug > > effects, but as an isolated phenomenon Raynaud's is pretty common, > so > > most people don't have associated disorders. Raynaud's is an > > exaggerated vascular response to cold temperature or emotional > stress > > manifest clinically by sharply demarcated color changes of the skin > > of the digits, usually the fingers. As an isolated phenomenon, the > > cause is abnormal local vasoconstriction regulated by the autonomic > > nervous system -- so it's not immunologic-based. However, there is > an > > immune-mediated connection in that some people with Raynauds have > > specific autoantibodies, which may or may not be related to the > kinds > > of immune activities found in connective tissue diseases. > > > > All the above is pretty much distinct from the immune system's > > involvement in combating infection disease. It's true that a post- > > viral syndrome is often evoked to explain ongoing activity of some > > part of the immune system immediately after fighting off a virus, > but > > most of those syndromes are very cleanly defined and have classic > > symptoms. That doesn't entirely rule out other post-viral > conditions, > > of course, but nowadays that's a grab-bag theory that can explain > any > > disease or disorder. So rosacea may be a post-viral syndrome, but > > from a practical perspective right now that doesn't help us > > understand rosacea or anticipate a treatment plan. We need to learn > > more about post-viral syndromes in general before we can relate it > to > > rosacea. Plus, the relationship may also be time coincidence, or it > > may have to do with some other aspect of the infection unrelated to > > the immune system. > > > > I don't know what " glandular fever " refers to. I assume ME refers > to > > myalgic encephalitis, which historically was thought to be what > they > > called chronic fatigue syndrome (CFS) in the early part of the 20th > > century. There is evidence of immune differences in patients with > CFS > > compared to healthy controls, but the importance of these changes > is > > unclear. These observations raise the possibility that some cases > of > > CFS are associated with a chronic inflammatory process (rosacea is > a > > chronic inflammatory condition), but the actual studies supporting > > this are very inconsistent, and even when present are relatively > > mild. Intuitively, I don't think that mainstream rosacea fits in > well > > here. > > > > The NIH relates CFS and fibromyalgia, a common cause of chronic > > musculoskeletal pain. Fibromyalgia is one of a group of soft tissue > > pain disorders that affect muscles and soft tissues such as tendons > > and ligaments. Importantly, neither fibromyalgia or CFS is > associated > > with tissue inflammation and the etiology of the pain and fatigue > is > > not thought to be immune-mediated. This is key: patients with > > fibromyalgia and, in particular, those labeled to have chronic > > fatigue syndrome, may be told or believe that their illness is > caused > > by an undiagnosed infection, but there's no direct evidence that > > these syndromes are related to persistent infection or ongoing > > immunologic abnormalities. Of course, these conditions may have > begun > > as a post-microbial syndrome. But I suspect the direct cause will > be > > found related to neurohormonal activity involving pain perception, > > fatigue, abnormal sleep, and depression, since many (alas, not all) > > respond to some form of therapy using tricyclic antidepressants and > > serotonin reuptake inhibitors. > > > > This is very, very confusing, heady stuff with an emphasis on > > research as much or more than on clinical medicine, which explains > > why I didn't go into immunology. I don't know that I have much > > more to say about any of these. > > > > I am intrigued by the whisper of immune-mediated pathology in > > rosacea. I'm going to educate myself on this more, and will share > > with the group anything interesting I uncover. I hope others will > do > > the same. > > > > Marjorie > > > > Marjorie Lazoff, MD Quote Link to comment Share on other sites More sharing options...
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