There’s something problematic about human tendons and cartilage. A wide range of infectious, auto-immune and idiopathic disorders land on them. I think dogs are no better, I can’t speak for other mammals.
We’ve tried to put boundaries around these disorders, to name them and attach treatments to the names. Some of our boundaries are better than others. Rheumatoid arthritis isn’t a bad tag. Osteoarthritis though, that label kind of sucks. It includes a wide range of clinical presentations at varied ages with diverse and poorly understood contributions of genetics, auto-immune activity, injury and healing, tendon and cartilage, inflammation and age. The one thing all of the diverse forms of osteoarthritis have in common is that there’s no useful treatment. We might as well call them the idiopathic untreatable arthritides (IUA).
Over the past 20 years or so IUA, or osteoarthritis, has had a few partitions. The biggest one so far was to carve out psoriatic arthritis; a history article claims it spun off in the 1960s (I thought 1980s, but maybe it took a while to make it into textbooks.) There have been efforts to split out “inflammatory osteoarthritis” (sometimes also called erosive osteoarthritis), but since there are no treatments (NSAIDs don’t count) IOA hasn’t quite launched.
I have something between psoriatic arthritis and inflammatory osteoarthritis, so I did a recent search of the UK’s Clinical Trials database for osteoarthritis + inflammatory, trials in UK, US, Canada and Germany and a similar search on the NIH ClinicalTrails.gov. The UK database draws on data from the WHO’s International Clinical Trails Registry Platform, but most of the trials were in the US. Of the two the UK database had the more interesting results.
These are the investigations for slowing disease progression that looked slightly interesting
- Hydroxychloroquine: This is an old antimalarial often used for Rheumatoid Arthritis and Psoriatic Arthritis. It’s something one could probably induce an adventurous rheumatologist to try. The most interesting possible mechanism of action is through inhibition of toll-like receptor (TLR) 9 family receptors, these are a part of the “innate immune system”. The role of the innate immune system in inflammatory osteoarthritis is interesting.
- ABT-981: Inhibitor of interleukin-1 (IL-1) alpha and IL-1 beta cytokines. More here.
- GSK3196165: HuCAL antibody, Granulocyte macrophage colony stimulating factor (GM-CSF) receptor agonist
- ABT-652: Histamine H3 receptor modulator. Targeting the H3 receptor is interesting because of a possible roll in Toll-like receptor activity and the innate immune system.
- Gevokizumab: monoclonal antibody inhibitor of interleukin-1 beta (IL-1 beta), a cytokine.
The innate immune system connection is new to me, but a search in Google had an auto-complete….
Spooky AI world indeed. Here’s the PubMed abstract for the article The Goog is suggesting, emphases mine:
Innate immune system activation in osteoarthritis: is osteoarthritis a chronic wound?
Curr Opin Rheumatol. 2008 Sep;20(5):565-72. Scanzello CR1, Plaas A, Crow MK.
PURPOSE OF REVIEW:
Synovial inflammation is increasingly recognized as an important pathophysiologic process in osteoarthritis, but the stimuli and downstream pathways activated are not well defined. Innate immune system activation, best documented in responses to pathogens, likely plays a role in induction of inflammatory mediators and the specific cellular infiltrate seen in osteoarthritis. Thus, the Toll-like receptors (TLRs) and their signaling pathways are of particular interest. These innate pattern-recognition receptors are activated not only by pathogens but by endogenous 'danger signals'. In this report, we review evidence that certain extracellular matrix components of joint tissues (hyaluronan and fibronectin) may act as TLR stimuli, and summarize recent literature implicating TLR activation in osteoarthritis.
Convincing evidence exists that hyaluronan/TLR interactions drive responses to tissue injury. Evidence of a similar role for fibronectin is growing. TLRs are expressed and functional in the joint, and many proteases and cytokines that promote cartilage catabolism are dependent on nuclear factor-kappaB, a TLR-activated transcription factor.
Activation of TLR pathways seems likely in osteoarthritis and may play a central role in disease development and progression. A model of osteoarthritis as a chronic wound, in which the innate immune response is triggered by molecular signals of tissue damage, is presented as a framework for future study of inflammation in this prevalent joint disease.
Well, well, well. That feels like me. I particularly liked this followup article from 2 years later, note the reference to dividing “osteoarthritis" into subsets:
The role of innate immunity in osteoarthritis: when our first line of defense goes on the offensive
J Rheumatol. 2015 Mar;42(3):363-71. doi: 10.3899/jrheum.140382. Epub 2015 Jan 15.
Although osteoarthritis (OA) has existed since the dawn of humanity, its pathogenesis remains poorly understood. OA is no longer considered a "wear and tear" condition but rather one driven by proteases where chronic low-grade inflammation may play a role in perpetuating proteolytic activity. While multiple factors are likely active in this process, recent evidence has implicated the innate immune system, the older or more primitive part of the body's immune defense mechanisms. The roles of some of the components of the innate immune system have been tested in OA models in vivo including the roles of synovial macrophages and the complement system. This review is a selective overview of a large and evolving field. Insights into these mechanisms might inform our ability to identify patient subsets and give hope for the advent of novel OA therapies.
So now I need to research currently FDA approved medications that are thought to be TLR antagonists, like H3 receptor antagonists. Ciproxifan could be ordered from suspicious Chinese suppliers. Ok, Am I feeling lucky?
Exploring the “similar articles” and “citing articles” streams for the 2008 Scanzello et al article is quite interesting. Maybe we’ll make some progress. I’ve added some of those articles to my Pinboard arthritis stream, quite a few have free full text and are PubReader viewable. (yay NLM — the only good thing GWB ever did). I have some reading to do.
PS. As of Jan 2016 there are no interesting hits on “Heberden’s Nodes” and “Innate Immunity”.
While discussing this with post with Emily something she said led us to a discussion of the curious history of the “H2 blockers”, particularly cimetidine (Tagamet). We remember when those drugs were introduced for gastric mucosa injury, as was common in OA patients taking NSAIDs.
The H2 blockers have an odd history with immune disorders. I recall eosiniphilic fasciitis had a curious response to cimetidine. Cimetidine is a physician-folk remedy for recurrent “cold sores” (usually ascribed to herpes simplex infection), which are now considered to be an innate immune response disorder. Cimetidine and ranitidine are also sometimes used to treat warts. As long ago as 1989 it was considered an immune response modifier, but researchers lost interest in the 00s. I did find a 2003 Japanese publication on cimetidine activity in suppressing rat adjuvant-induced experimental arthritis and a 2011 article suggesting sedating first-generation antihistamines and H2 blockers (cimetidine) impair innate immune responses to bacterial infection in mice.
On the other hand, there are some studies suggesting Cimetidine increases NK cell activity. I could easily see how shifting H2/3 balances would worsen osteoarthritis. I’m not quite ready to start taking a nightly cocktail of over-the-counter cimetidine and chlorpheniramine.
If you Google on Cimetidine and Osteoarthritis you’ll find a factmed page titled “Is Osteoarthritis a side-effect of cimetidine?” It says “Between January 2004 and October 2012, 78 individuals taking CIMETIDINE reported OSTEOARTHRITIS to the FDA…. of 2258 CIMETIDINE drug adverse event reaction reports”
I think what this group does is to dump the FDA FAERS files into Microsoft Access, then they generate web pages for each Drug - Condition pair and they sell ads off the pages. It’s a not-quite-criminal but not-quite-wonderful enterprise.
I doubt this is a meaningful finding, but if cimetidine truly does act on histamine receptors associated with NK activity and/or innate immunity it would not be surprising if it made some diseases worse as well as some better!
My intuition is not misplaced…
Antihistamines as treatments for autoimmune disease?
Nature Reviews Rheumatology 9, 696 (2013) doi:10.1038/nrrheum.2013.169
Published online 29 October 2013
I’ve found articles on immune modulation activity of H1 and H2 antagonists, like chlorpheniramine, cimetidine and ranitidine dating back to the 1980s, including speculation on H1 and H2 receptor activity on human chondrocytes. Many starts and stops, but now we have innate immune system and the H3 and H4 receptors…
The Buckland article merely recapitulated an H4 blocker review — not worth paying Nature $8.
Meanwhile, I’ve started my own quixotic trial - Cimetidine 400mg/daily. A true shot in the dark, but it’s not like there are any alternatives. I’ll report out an ’n of 1’ observational result in 4-6 weeks one way or another. I reserve the right to terminate the trial if things go abruptly downhill but I’ll report out regardless.
Prion Disease and the Innate Immune System - mast cells in the brain play a role - of some kind. So what does cimetidine do there?
Upregulation of H2 receptors after cimetidine use - a risk of rebound with this experiment.
Cimetidine decreases calcium levels and improves symptoms in patients with hyperparathyroidism… Cimetidine, 200 mg twice daily, was given orally for 3 months in 16 patients who did not respond to more than 6 months of conservative treatment… Calcium deposits disappeared in 9 patients (56%), decreased in 4 patients (25%), and did not change in 3 patients (19%) . Our results indicate that cimetidine is effective in treating chronic calcifying tendinitis of the shoulder; however, the mechanism by which cimetidine improves the symptoms is unknown.
Weird. I do have a long history of intermittent calcific tendinitis of the shoulders, though I’ve always managed it conservatively. There is only one article citing this study…The H2 blocker famotidine suppresses progression of ossification of the posterior longitudinal ligament in a mouse model. - PubMed - NCBI
This is peculiar …
… Cimetidine is a useful medical treatment for bladder pain but the presence or absence of gastrin or histamine-like immunoreactivity does not explain its therapeutic benefit….