Prevention of appearance of radiological lesions in early rheumatoid arthritis: a randomized, single-blind study comparing intra-articular rifamycin with auranofin

Vaccination with endosomal unknown epitopes produces therapeutic response in rheumatoid arthritis patients and modulates adjuvant arthritis of rats

Background

Our previous results showed that intrasynovial Rifamycin SV caused the lysis of synoviocites and freed the autoantigens which in turn stimulated the immunoregulatory rather than autoreactive T cell response in rheumatoid patients. Here, we hypothesize that disruption in vitro of peripheral blood mononuclear cells, by freeze/thawing or by lytic action of Rifamycin SV, would induce the release of endosomal pathogenic autoantigens from APCs present in the circulation, which could then be isolated from degrading enzymes by ultrafiltration.

Methods

The preparation of the ultrafiltrates are based on the rupture of PBMCs (5 × 10⁶ cells/mL) by the addition of Rifamycin SV in culture (250 μg/mL), which causes the lysis of 90 % of the cells in 3 h, or by three cycles of freeze/thawing of the PBMC, from −80 °C to room temperature. The lysate and the fragmented cells were then centrifuged and ultrafiltered by passage through a filtration device with a cut-off of 10 kDa. Also the synovial fluid was subjected to ultrafiltration.

Results and conclusions

At clinical monitoring of the 30th day, 22/58 (38 %) patients subcutaneously treated with the autologous ultrafiltrate prepared by the freeze/thawing of PBMCs reached an ACR20. Comparable results were obtained with the other two ultrafiltrates.

Cell cultures The addition of ultrafiltrates to rheumatoid PBMCs cultures led to the upregulation of a marker for T-regulatory cells, and downregulation of a cell proliferation marker; changes that together have the meaning of a global immunomodulatory response and that only a specific antigen (ultrafiltrate UF-f/t) might induce in the rheumatoid patient, probably by activating pre-existing protective network.

Experimental arthritis All the ultrafiltrates except that prepared by Rifamycin SV were able to modulate the adjuvant arthritis in rats. In particular, longlasting synovial fluid induced a significant reduction of the severity of subsequent arthritis (p < 0.01) while SF from recent RA effusion (5–10 days after a previous complete extraction) and knee osteoarthrosis were ineffective. It is reasonable to assume there are at least two unknown endosomal immunoactive epitopes; one developing its immunotherapeutic property in RA, and the other, related to the molecule of HSP60, reduces the severity of oncoming arthritis. Both epitopes are present in humans, have a molecular weight of ≤10 kDa and do not appear to be bystander antigens. Please see Additional file 1 for the abstract in Italian.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-016-0908-7) contains supplementary material, which is available to authorized users.

3-(Carboxyalkylthio) rifamycin S and SV derivatives inhibit human neutrophil functions

In order to further investigate the potential of rifamycins as antiinflammatory drugs, twenty-five semisynthetic rifamycins were tested at concentrations ranging from 10(-9) to 10(-5) M on in vitro human neutrophil functions such as locomotion, superoxide anion production, and degranulation, under different stimulatory conditions. They were also tested as antiproliferative agents on peripheral blood lymphocytes. The present semisynthetic derivatives are in general characterized by their carrying a hydrophilic substituent; they are rifamycin S or rifamycin SV derivatives carrying at C(3) either a carboxyalkyl side-chain or a glycosyl side-chain. Derivatives of the former group displayed inhibitory activities covering the whole range of activities tested, suggesting that the sum of these different effects could support their antiinflammatory activity in vivo. These derivatives, carrying a free carboxyl, are more water soluble than rifamycin SV at physiological pH, and may serve as antiinflammatory drugs for local administration, alternative to rifamycin SV, possibly giving higher efficacy and reduced side effects of pain and tissue swelling.

Twenty years of experience with intra-articular rifamycin for chronic arthritides

Rheumatoid arthritis is a chronic progressive disease causing substantial morbidity and mortality for which current treatments are largely unsatisfactory. Over the past 20 years we have developed a novel therapeutic approach based on the intra-articular administration of rifamycin. The published studies on rifamycin therapy of rheumatoid arthritis and other chronic arthritic disorders, mainly from our group, are reviewed. Our results indicate that intra-articular rifamycin is effective against active synovitis and can profitably be combined with any basic therapy with slow-acting antirheumatic drugs. There is good evidence that the development of new erosions can be prevented or delayed by this treatment and that the balance between side-effects (mainly local pain) and antiarthritic activity is very favourable in the long term. Our observations have led us to hypothesize a possible systemic effect of rifamycin injected multilocally in peripheral joints; we believe that the available data deserve further investigation by independent researchers.

Rifamycins inhibit human neutrophil functions: new derivatives with potential antiinflammatory activity

In our study we investigated the effect of rifamycin SV, rifamycin B, rifampicin and five semisynthetic derivatives on human neutrophil functions such as locomotion, superoxide production and degranulation stimulated by specific agonists. All compounds were tested at concentrations ranging from 10(-9) to 10(-5) M. Among the newly synthesized compounds the most active we found to be the derivatives carrying an acidic substituent at C3: these significantly lowered the superoxide generation induced by PMA throughout the entire concentration range, whereas rifamycin SV, rifamycin B and rifampicin were effective only at the highest concentrations. Moreover, chemotactic movement was significantly attenuated by derivative R4, rifamycin B and rifamycin SV at high doses; granule enzyme release was unaffected by all compounds.

Antimicrobial therapy for rheumatoid arthritis

New interest in the use of antibiotics in the treatment of arthritis was stimulated by two factors: (1) observations that, in some forms of chronic arthritis, microbial antigens persist in the synovial membrane, and (2) the increasing knowledge of the anti-inflammatory and immunosuppressive effects of antibiotics. Recently, several published controlled studies reported a beneficial effect of tetracyclines on RA and reactive arthritis. Whether the anti-arthritic activity of the tetracyclines investigated is mediated by the antimicrobial, anti-inflammatory or immunomodulatory properties remains to be determined. It may be concluded from these studies that tetracyclines have a beneficial effect on RA, especially when laboratory parameters are considered. The effect on the clinical parameters is not unequivocal. The adverse effects seem to be mild but the long-term efficacy and safety of tetracyclines as disease-modifying antirheumatic drugs remain to be demonstrated.

Rifamycin SV administered by intra-articular infiltrations shows disease modifying activity in patients with pauci- or polyarticular juvenile rheumatoid arthritis

The therapeutic activity of rifamycin SV administered by the intra-articular route was evaluated in 52 children with juvenile rheumatoid arthritis (oligopolyarthritis). Each active joint was injected once a week for 10 weeks; thereafter patients were followed for 3-48 months. The number of active joints and joints with limitation of motion, the erythrocyte sedimentation rate (ESR) and C-reactive protein improved significantly at the end of the treatment cycle, with progressive improvement during the subsequent period of observation. At 48-month of follow-up, 78% of joints did not present signs of inflammation; and 66% of joints showed no functional limitations. Joints without radiological lesions at baseline and large joints responded best to the rifamycin treatment. Persistent knee effusions were reabsorbed completely in most cases during the treatment and within the first 6 months of follow-up. Recurrences of synovitis were observed in 7% of joints. De novo radiological lesions in initially undamaged joints occurred during the second year of follow-up in only 10% of patients. At 24 months, 62% of patients with oligoarthritis and 24% with polyarthritis showed complete remission in all affected joints and recovered movement in all those joints which had shown limitations at baseline. There was also a normalization of inflammatory indexes (ESR, C-reactive protein) and regression of general features of disease. Further long term studies are now required to confirm these promising preliminary results.