So I'm now halfway through my fourth round of PPS. To recap, I am doing a course of PPS injections annually, after a very positive experience treating facet joint arthritis in my lower back. I am pretty much symptom free now, so I am really undertaking this treatment for preventative reasons, and maintenance.
My hope is to arrest, maintain and potentially reverse my spinal OA, while also protecting my other joints from any arthritic condition that has not yet become symptomatic. I am trying to make myself bulletproof.
I have been getting MRIs along the way and you can read above about the disappearing bone marrow lesions. I just did an MRI before starting my current course, and the results are really quite boring: everything is stable, arthritis is still in check, the condition has not advanced. No news is good news. Barely worth posting. This is all very good.
But there is one feature that may be worth commenting on. As well as arthritis I also have disc degeneration at the affected vertebrae. The L3/L4 and L4/L5 discs are desiccated, dried out. You can see this in the MRIs.
I have laid out four MRIs below taken roughly one year apart. The first is before treatment. The second is after my first pentosan treatment. The third is after the next pentosan treatment. The fourth image is a year later but there is no treatment between the third and fourth images.
Lighter regions in the MRI have higher water content. A healthy disc has a gel-like interior that supports and cushions the spine. The healthy discs are light in the image. But the two discs I marked with arrows are dark, indicating they have lost water. If you look at these two discs in the later MRIs they appear lighter, indicating rehydration, reversal of the original disc degeneration.
This effect is consistent with what we know about PPS's action. The gel within the disc is comprised of hyaluronic acid, aggregated with various other proteoglycans (eg. aggrecan, versican). We know that PPS upregulates production of HA and proteoglycans. We know that it favours synthesis of higher molecular weights of these polymers. So it seems quite reasonable that PPS is playing a role in disc regeneration.
[There is a great deal of information on PPS and disc regeneration in the review "Pentosan Polysulfate, a Semisynthetic HeparinoidDisease-Modifying Osteoarthritic Drug with Roles in Intervertebral Disc Repair Biology Emulating the Stem Cell Instructive and Tissue Reparative Properties of Heparan Sulfate".]
The main changes are seen after the first treatment. Things are pretty stable after that. Certainly the discs have not returned to the initial degenerated condition.It also looks like there may be some improvement in the disc bulges impinging on the spinal cord. I think increase in disc volume could bring those protrusions back in, although I am no expert in these things and this is speculation on my part.
(20min delay)