Efficacy of Subantimicrobial Dose Doxycycline for Moderate-to-Severe and Active Graves' Orbitopathy

One Incremental Stride for Doxycycline, One Substantial Advancement for Thyroid Eye Disease

The aim of this study is to assess the effectiveness of a 12-week doxycycline treatment for thyroid eye disease (TED), an autoimmune condition associated with thyroid dysfunction. In this randomized controlled clinical trial, 82 patients were randomly assigned at a 1:1 ratio to receive doxycycline (50 mg) or to undergo no treatment. Various metrics, including margin reflex distance (MRD1 and MRD2), eyelid aperture, levator muscle function, lagophthalmos, proptosis, ocular motility, diplopia, and Graves' ophthalmopathy-specific quality-of-life (GO-QOL) scale scoring were assessed. Exclusion criteria were uncontrolled systemic diseases, tetracycline allergies, pregnancy, lactation, or age below 18. The mean age was 51.6 years (SD), 87.8% of participants were female, and all were Caucasians. By week 12, the doxycycline group exhibited a significant improvement rate based on MRD2 (from 4 to 15 participants with physiological findings), clinical activity score (from 7 to 35 participants with non-active disease), and GO-QOL (from 51.22% to 70.73% of participants with a good life quality). Doxycycline showcased anti-inflammatory and immunomodulatory effects in treating TED, suggesting its potential efficacy for TED and other orbit inflammatory conditions. However, these results warrant further validation through future research involving extended follow-up periods and larger cohorts.

Can tetracyclines ensure help in multiple sclerosis immunotherapy?

BACKGROUND

Multiple sclerosis (MS) is a disease of the central nervous system where an autoimmune response leads to chronic inflammation. It represents the second leading cause of non-traumatic disability in the world, affecting mainly young adults and with high female to male incidence. At present, the causative agent in MS is unknown, preventing the development of prophylaxis policies and the understanding of how the human system copes with this complex inflammation. Tetracyclines (Tet) have attracted great attention due to their anti-inflammatory effects. Minocycline and doxycycline represent the second-generation Tet that have been largely used to treat acne and to suppress inflammation. In addition, they are safer and cheaper than other drugs currently used to treat MS.

AIM

This study aims to review recent data involving the Tet minocycline and doxycycline and their therapeutic potential in MS.

RELEVANCE FOR PATIENTS

Many of the drugs used to treat MS have severe side effects and are costly. Tet, on the other hand, are a safe and inexpensive class of drugs that can modulate the immune response in MS patients.

Immunotherapy of Autoimmune Diseases with Nonantibiotic Properties of Tetracyclines

Tetracyclines, which have long been used as broad-spectrum antibiotics, also exhibit a variety of nonantibiotic activities including anti-inflammatory and immunomodulatory properties. Tetracyclines bind to the 30S ribosome of the bacteria and inhibit protein synthesis. Unlike antimicrobial activity, the primary molecular target for the nonantibiotic activity of tetracycline remains to be clarified. Nonetheless, the therapeutic efficacies of tetracyclines, particularly minocycline and doxycycline, have been demonstrated in various animal models of autoimmune disorders, such as multiple sclerosis, rheumatoid arthritis, and asthma. In this study, we summarized the anti-inflammatory and immunomodulatory activities of tetracyclines, focusing on the mechanisms underlying these activities. In addition, we highlighted the on-going or completed clinical trials with reported outcomes.

Double-blind placebo-controlled randomized clinical trial evaluating doxycycline effects on chemotherapy-induced oral mucositis

WHAT IS KNOWN AND OBJECTIVE

Chemotherapy (CT)-associated oral mucositis (OM) is one of the most debilitating and painful side effects in oncology patients, with limited effective management options. During CT, matrix metalloproteinases (MMPs) are upregulated, causing damage in mucosal and submucosal tissues, and playing a key role in OM; therefore, the use of subantimicrobial doxycycline as a MMP inhibitor may represent a potential approach for OM management. The aim of this clinical trial was to evaluate the efficacy and safety of low doses of doxycycline in OM development in individuals with acute leukaemia (AL) during CT.

METHODS

Randomized controlled clinical trial (Registration No. NCT01087476) performed in adult AL patients scheduled to receive CT (September 2010-October 2014). Individuals were stratified by leukaemia type and assigned randomly to receive doxycycline hyclate (50 mg/d) (doxycycline group: DG) or placebo (placebo group: PG) before and during CT. Included subjects had a baseline oral examination and thereafter 3 times a week during 21 days. The primary outcome was OM development.

RESULTS AND DISCUSSION

One hundred and forty-seven AL subjects were enrolled: 74 in DG and 73 in PG; baseline characteristics between groups were comparable. During follow-up, 15 (10.2%) individuals developed OM; no differences between treatment groups were found (DG:8.1%, PG:12.3%; P = .59). The mean OM Assessment Scale score was 2.51, without differences between groups (DG:2.7, PG:2.4; P = .65). Low baseline blood albumin levels in the OM-affected individuals were identified, revealing the effect of systemic deterioration as a predisposing factor for OM development. No adverse effects were observed.

WHAT IS NEW AND CONCLUSION

Subantimicrobial doses of doxycycline did not reduce the incidence, onset, duration or severity of OM.