Levofloxacin treatment in patients with rheumatoid arthritis receiving methotrexate.

Background: Sulfasalazine and tetracyclines are effective against rheumatoid arthritis (RA). Levofloxacin, the bacteriologically active isomer of ofloxacin, is used in the treatment of infections caused by periodontopathic bacteria and facultative anaerobic bacteria. The aim of this study is to evaluate the clinical efficacy, safety, and tolerability of levofloxacin in patients with rheumatoid arthritis.

Methods: In a 6-month, double-blind trial, we randomly assigned 76 patients with persistently active rheumatoid arthritis despite at least 6 months of methotrexate therapy at a stable dose of 15 to 25 mg per week to receive either levofloxacin (500 mg) or placebo orally once daily while continuing to receive methotrexate. The change from baseline to six months in the swollen-joint count and tender-joint count was the primary measure of efficacy. Secondary endpoints included pain, quality of life, duration of morning stiffness, erythrocyte sedimentation rate, C-reactive protein level, and physician's and patient's global assessments. The data were also analyzed to determine the number of patients meeting American College of Rheumatology criteria for 20, 50, and 70% improvement.

Results: The levofloxacin plus methotrexate was associated with the greatest reduction in the number of swollen or tender joints (P < 0.001). The levofloxacin plus methotrexate group also had significant improvement in many of the secondary outcome measures (P < 0.001). Levofloxacin was well tolerated. There were no dose-limiting toxic effects.

Conclusion: In patients with active rheumatoid arthritis who received methotrexate, treatment with levofloxacin significantly improved the signs and symptoms of rheumatoid arthritis.

Key Words: rheumatoid arthritis, levofloxacin, treatment

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The etiology of rheumatoid arthritis (RA) remains elusive, although it appears that genetic, infectious, environmental, and hormonal factors are all involved in complex, interrelated ways. (1)

In many previous studies, this rheumatic disease has been found at increased frequencies in individuals with periodontitis, and rheumatoid arthritis resembles periodontitis in many pathologic aspects. (2,3) HLA-DR4 tissue antigens are found at high frequencies both in patients with periodontitis and in those with RA. (4,5) High levels of oral anaerobic bacterial antibodies have been found in the serum and synovial fluid of RA patients. (6,7)

Sulfasalazine, tetracyclines, ornidazole, and clindamycin are effective against this disease. (8-11) Clindamycin and ornidazole are used in the treatment of infections caused by anaerobic bacteria. Alteration of bowel flora has been a proposed mechanism of action for sulfasalazine, and it has been shown that patients with inflammatory bowel disease treated with sulfasalazine have decreased numbers of nonsporing anaerobes. (12)

Levofloxacin is a bacteriologically active isomer of ofloxacin. It is a fluoroquinolone with activities against both facultative anaerobic bacteria and anaerobic bacteria. Levofloxacin has an immunomodulatory action and significantly inhibits both human and mouse monocytic IL-1 and TNF-alpha synthesis. (13) Biologic treatment agents and specifically, tumor necrosis factor (TNF) alpha blockers are effective in rheumatoid arthritis therapy. (14) Periodontopathic bacteria are powerful stimulators for TNF-alpha and other pro-inflammatory cytokines in humans. (15-18)

We performed a study to evaluate the efficacy of levofloxacin, a fluoroquinolone antibiotic, for the treatment of rheumatoid arthritis.

Methods

Patients

The study was conducted from June to December 2005. Patients were recruited from rheumatology practices in southern Turkey. Patients enrolled in this study met the American College of Rheumatology (formerly, the American Rheumatism Association) criteria for the diagnosis of RA (functional classes I, II, or III). (19) Patients had active disease defined as [greater than or equal to]12 tender joints based on a 68-joint assessment, [greater than or equal to]10 swollen joints based on a 66-joint evaluation, and either an erythrocyte sedimentation rate (ESR) [greater than or equal to]28 mm/h or a serum C-reactive protein (CRP) concentration [greater than or equal to]2.0 mg/dL.

Before receiving the study drugs, all the patients had been taking methotrexate for at least 6 months, at a stable dose of 15 to 25 mg per week for the previous four weeks (weekly doses as low as 10 mg were acceptable for patients who could not tolerate higher doses). All patients received folic acid or folinic acid to mitigate the toxic effects of methotrexate.

The study patients discontinued therapy with sulfasalazine and hydroxychloroquine at least two weeks before starting the study drug and disease-modifying antirheumatic drugs other than methotrexate at least four weeks before. Patients who were receiving nonsteroidal anti-inflammatory drugs, prednisone (at 10 mg daily or less), or both, were eligible if the doses had been stable for at least four weeks before the study period and continued to be stable during the study period.

Study Protocol

This was a 6-month, monocenter, randomized, double-blind, placebo-controlled study. This study was approved by the local ethics committee and was carried out in accordance with the principles of the Declaration of Helsinki. Before entering this study, all patients gave written informed consent.

Clinical disease variables included complete count of swollen and tender joints (68 joints evaluated; cervical spine and hips evaluated only for tenderness); duration of morning stiffness; Health-Assessment Questionnaire (HAQ) (20); physician's and patient's global assessment, on a scale from 0 (asymptomatic) to 10 (severe symptoms); patient's assessment of pain, on a visual-analog scale from 0 (no pain) to 10 (severe pain) (21); Westergren erythrocyte sedimentation rate; and CRP. (22)

A patient could be withdrawn from the trial at any time after enrollment for the following reasons: the patient's request, pregnancy, serious infection, severe or life-threatening adverse event, or inadequate control of arthritis symptoms (>50% increase in the total number of swollen or tender joints) necessitating an increase in the systemic corticosteroid dosage or reinstitution of therapy with disease-modifying antirheumatic drugs.

Other exclusion criteria were impaired hepatic enzyme tests, impaired renal function, untreated hypertension, diagnosis of other inflammatory joint diseases, impaired bone marrow function, recent serious infections, and any clinically relevant cardiovascular, hepatic, neurologic, endocrine, or other major systemic diseases. Follow-up evaluations after the discontinuation of therapy at six months were completed every two weeks for one month, then once a month until the patient required new or previous antirheumatic therapy or until the total count of swollen and tender joints returned to the baseline value. Hematologic testing, serum chemistry, and urinalysis were repeated periodically during the trial, including follow-up, and on the day the patient required initiation or reinstitution of therapy with disease-modifying antirheumatic drugs or until the joint count returned to the baseline value. All patients were evaluated for side effects and laboratory abnormalities.

Treatment

Patients were randomly assigned to one of two treatment groups: oral placebo or oral levofloxacin 500 mg once daily. The patients received stable doses of oral or subcutaneous methotrexate.

Concomitant Medications

The use of analgesics such as acetaminophen, codeine, or propoxyphene for pain relief was permitted.

Statistical Analysis

The change from baseline to six months in the swollen-joint count and tender-joint count was the primary measure of efficacy. Secondary endpoints included pain, quality of life, duration of morning stiffness, erythrocyte sedimentation rate, C-reactive protein level, and physician's and patient's global assessments. If a subject withdrew from the study, the last available value was used as the six-month value.

The data were also analyzed to determine the number of patients meeting American College of Rheumatology criteria for 20, 50, and 70% improvement. An ACR 20 response is defined as a reduction of at least 20% in the number of tender and swollen joints plus an improvement of at least 20% in at least three of the following five criteria: patient's assessment of pain, patient's assessment of disease activity, physician's assessment of disease activity, patient's assessment of physical function, and serum C-reactive protein concentration. (23,24) ACR 50 and ACR 70 are defined in the same manner as ACR 20 but with [greater than or equal to]50% or [greater than or equal to]70% degree of improvement, respectively.

The values were compared with use of analysis of variance. The percentages of patients with ACR 20, ACR 50, and ACR 70 responses were compared with use of [chi square] tests. Fisher exact tests were used to compare the incidence of adverse events in the levofloxacin plus methotrexate group and the placebo plus methotrexate group.

Results

The characteristics of the patients before treatment are summarized in Table 1. Nineteen men and 57 women were enrolled in the trial. The mean age was 50 years. No significant differences between groups were detected in pretreatment characteristics or baseline disease activity. The primary reason for withdrawal was inadequate control of arthritis symptoms. Among the patients receiving levofloxacin plus methotrexate, the proportions of patients who withdrew because of inadequate symptom control were 5%; among the patients receiving placebo plus methotrexate, it was 11%.

Efficacy

Levofloxacin plus methotrexate produced significant improvement in all measures of disease activity (Table 2). The 500 mg dose of levofloxacin was associated with the greatest reduction in the number of swollen or tender joints (P < 0.001).

Three patients had periodontal disease in the levofloxacin treatment group. Gingival bleeding disappeared after the levofloxacin treatment.

Levofloxacin plus methotrexate treatment was also associated with significant reductions in pain and duration of morning stiffness, significant improvement in the quality of life and physician's and patient's global assessments, and significant reductions in disease activity as assessed by objective laboratory measures (erythrocyte sedimentation rate and C-reactive protein level). Levofloxacin plus methotrexate was superior to methotrexate and placebo (P < 0.001). A significantly greater percentage of patients treated with 500 mg of levofloxacin met the ACR 20% improvement criteria (ie, achieved an ACR 20 response) at 6 months compared with patients who received placebo (57.9 versus 18.4%; P < 0.001). Greater percentages of patients treated with 500 mg of levofloxacin also achieved ACR 50 responses (34.2 versus 7.9%; P < 0.001) and ACR 70 responses (18.4 versus 2.6%; P < 0.001) compared with patients who received placebo (Table 3).

Safety and Tolerability

Levofloxacin was well tolerated, and no deaths were reported by levofloxacin-treated patients after six months of treatment. There were no dose limiting toxic effects. Adverse events due to levofloxacin plus methotrexate were not frequent. The most frequently reported adverse events in the levofloxacin and placebo treatment groups (seen in at least 5% of patients, and excluding worsening of RA) were gastrointestinal pain (15.6% and 5.3%, respectively), headache (18.4% and 15.6%, respectively) and nausea (15.6% and 13.2%), respectively)(Table 4). Only one patient withdrew because of an adverse event related to levofloxacin (vomiting). No major abnormalities in hematologic findings or serum chemical profiles were noted during or after the study; in fact, improvements in anemia and decreases in platelet counts were seen, which reflect a reduction in disease activity.

Discussion

The results of this randomized, double-blind study show the clinical efficacy of levofloxacin in patients with active rheumatoid arthritis receiving methotrexate. In this six-month study in patients who had persistent disease activity despite methotrexate therapy, the addition of levoflaxacin provided additional benefit without potentiating the toxic effects of methotrexate or inducing dose-limiting toxic effects of its own. The few adverse events noted, were mild and easily managed.

Levofloxacin, the bacteriologically active isomer of ofloxacin, is used in the treatment of infections caused by periodontopathic bacteria and facultative anaerobic bacteria. Porphyromonas gingivalis, Prevotella intermedia, Prevotella melaninogenica, and Bacteroides forsythus are Gram negative anaerobic bacteria and are considered to be directly responsible for the periodontitis (periodontopathic bacteria). (25) They are found commensally in the body flora, where they cause chronic sinusitis, chronic recurrent tonsillitis, bronchitis, pneumonia, chronic otitis media, parotitis, intra-abdominal infection, genitourinary infection, and wound infections in immune-suppressed individuals as well as when in conjunction with facultative anaerobic bacteria (ie, Streptococcus pyogenes, Staphylococcus aureus, Haemophilus influenzae, Klebsiella pneumonia, Proteus mirabilis, and Escherichia coli).

Citrullination or deimination of arginine residues in autoantigenic proteins (profilaggrin/filaggrin, fibrinogen/fibrin, keratin, and vimentin) creates epitopes that are targeted by rheumatoid autoantibodies. (26) Arginine is the most important of the amino acids associated with autoantigenicity in proteins. Porphyromonas gingivalis has arginine/lysine-specific cysteine proteases. Tannerella forsythensis and Treponema denticola have arginine-specific protease. (27)

RA patients have significantly fewer galactose residues on their IgG Fc compared with age-matched healthy control subjects. A lack of terminal galactose residues early in disease is associated with a worse prognosis. (28) Prevotella melaninogenica, as a saccharolytic bacteria, disintegrates galactose. Consequently, P. melaninogenica causes this condition by binding to the Fc region of the IgG molecule and metabolizing galactose with its enzymes. (29)

High levels of oral anaerobic bacterial heat-shock proteins have been found in the serum of RA patients. (30) P. melaninogenica and P. intermedia heat-shock proteins of approximately 70kDa have been found in periodontal disease processes. (31) Hsp 70 antibodies have been detected in the synovial tissue of RA patients, and when the hsp 70 expression is induced with certain stress-stimulating factors, proinflammatory cytokines (TNF-alpha, IL-1, IL-6) develop in the RA synovium. (32)

Conclusion

Levofloxacin treatment in rheumatoid arthritis is very economical compared with TNF-alpha blockers. It can be concluded from this study that levofloxacin is an effective treatment for rheumatoid arthritis. The above evidence indicates that oral anaerobic bacteria could be important in the etiopathogenesis of RA. However, further studies are needed to confirm this.

References

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2. Mercado FB, Marshall RI, Klestov AC, et al. Relationship between rheumatoid arthritis and periodontitis. J Periodontol 2001;72:779-787.

3. Greenwald RA, Kirkwood K. Adult periodontitis as a model for rheumatoid arthritis (with emphasis on treatment strategies). J Rheumatol 1999;26:1650-1653.

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5. Gran JT, Husby G, Thorsby E. The association between rheumatoid arthritis and HLA antigen DR4. Ann Rheum Dis 1983;42:292-296.

6. Moen K, Brun JG, Madland TM, et al. Immunoglobulin G and A antibody responses to Bacteroides forsythus and Prevotella intermedia in sera and synovial fluids of arthritis patients. Clin Diagn Lab Immunol 2003;10:1043-1050.

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9. Gompels LL, Smith A, Charles PJ, et al. Single-blind randomized trial of combination antibiotic therapy in rheumatoid arthritis. J Rheumatol 2006;33:224-227.

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11. Ogrendik M, Hakguder A, Keser N. Treatment of rheumatoid arthritis with ornidazole: a randomized, double-blind, placebo-controlled study. Rheumatology (Oxford) 2006;45:636-637.

12. Das KM. Sulfasalazine therapy in inflammatory bowel disease. Gastroenterol Clin North Am 1989;18:1-20.

13. Riesbeck K. Immunomodulating activity of quinolones: review. J Chemother 2002;14:3-12.

14. Moreland LW, Baumgartner SW, Schiff MH, et al. Treatment of rheumatoid arthritis with a recombinant human tumor necrosis factor receptor (pg75)-Fc fusion protein. N Engl J Med 1997;337:141-147.

15. Seymour GJ, Gemmell E. Cytokines in periodontal disease: where to from here? Acta Odontol Scand 2001;59:167-173.

16. Yoshimura A, Hara Y, Kaneko T, et al. Secretion of IL-1 beta, TNF-alpha, IL-8 and IL-1ra by human polymorphonuclear leukocytes in response to lipopolysaccharides from periodontopathic bacteria. J Periodontal Res 1997;32:279-286.

17. Kjeldsen M, Holmstrup P, Lindemann RA, et al. Bacterial-stimulated cytokine production of peripheral mononuclear cells from patients of various periodontitis categories. J Periodontol 1995;66:139-144.

18. Rossano F, Rizzo A, Sanges MR, et al. Human monocytes and gingival fibroblasts release tumor necrosis factor-alpha, interleukin-1 alpha and interleukin-6 in response to particulate and soluble fractions of Prevotella melaninogenica and Fusobacterium nucleatum. Int J Clin Lab Res 1993;23:165-168.

19. Arnett FC, Edworthy SM, Bloch DA, et al. The American Rheumatism Association 1987 revised criteria for the classification of rheumatoid arthritis. Arthritis Rheum 1988;31:315-324.

20. Pincus T, Summey JA, Soraci SA Jr, et al. Assessment of patient satisfaction in activities of daily using a modified Stanford Health Assessment Questionnaire. Arthritis Rheum 1983;26:1346-1353.

21. Fries JF, Spitz PW, Young DY. The dimensions of health outcomes: the health assessment questionnaire, disability and pain scale. J Rheumatol 1982;9:789-793.

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24. Felson DT, Anderson JJ, Lange ML, et al. Should improvement in rheumatoid arthritis clinical trials be defined as fifty percent or seventy percent improvement in core set measures, rather than twenty percent? Arthritis Rheum 1998;41:1564-1570.

25. Boutaga K, van Winkelhoff AJ, Vandenbroucke-Grauls CM, et al. Periodontal pathogens: a quantitative comparison of anaerobic culture and real-time PCR. FEMS Immunol Med Microbiol 2005;45:191-199.

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29. Haraldsson G, Meurman JH, Kononen E, et al. Properties of hemagglutination by Prevotella melaninogenica. Anaerobe 2005;11:285-289.

30. Yoshida A, Nakano Y, Yamashita Y, et al. Immunodominant region of Actinobacillus actinomycetemcomitans 40-kilodalton heat shock protein in patients with rheumatoid arthritis. J Dent Res 2001;80:346-350.

31. Ando T, Kato T, Ishihara K, et al. Heat shock proteins in the human periodontal disease process. Microbiol Immunol 1995;39:321-327.

32. Schett G, Redlich K, Xu Q, et al. Enhanced expression of heat shock protein 70 (hsp70) and heat shock factor 1 (HSF1) activation in rheumatoid arthritis synovial tissue: differential regulation of hsp70 expression and hsf1 activation in synovial fibroblasts by proinflammatory cytokines, shear stress, and antiinflammatory drugs. J Clin Invest 1998;102:302-311.

Mesut Ogrendik, MD

From the Division of Rheumatology, Nazilli State Hospital, Nazilli, Turkey.

Reprint requests to Mesut Ogrendik, MD, Altintas mah. Kocacami cad., Erten Kocabay Apt., No:2 Kat:6, 09800, Nazilli-Aydin, Turkey. Email: [e-mail]

Accepted July 31, 2006.

RELATED ARTICLE: Key Points

* High levels of oral anaerobic bacterial antibodies have been found in the serum and synovial fluid of rheumatoid arthritis (RA) patients.

* Sulfasalazine, tetracyclines, ornidazole, and clindamycin are effective against RA. This study suggests that levofloxacin is effective in patients with RA.

* Oral anaerobic bacteria could be important in the etiopathogenesis of RA.

* Levofloxacin treatment in rheumatoid arthritis is very economical compared with TNF-alpha blockers.

Table 1. Demographic and baseline characteristics of the patients

                                        Placebo +     Levofloxacin +
                                        Methotrexate  Methotrexate
Characteristic no. (%)                  (n = 38)      (n = 38)

Mean age (yr)                           49 (10)       51 (9)
Female sex (%)                          74            71
Disease duration (yr)                   12 (8)        13 (9)
RF positivity (%)                       74            84
Swollen-joint count                     18 (6)        20 (12)
Tender-joint count                      29 (10)       32 (9)
Morning stiffness (hr)                   4.6 (1.4)     4.1 (1.0)
Physician's assessment (a)               7.2 (2.6)     6.8 (2.3)
Patient's assessment (a)                 6.7 (1.9)     6.1 (1.6)
Pain (visual analog scale) (a)           6.8 (1.5)     6.5 (1.7)
HAQ (b)                                  1.76 (0.5)    1.78 (0.7)
Erythrocyte sedimentation rate (mm/hr)  57 (21)       49 (19)
C-reactive protein (mg/dL)               3.9 (2.1)     3.8 (3.4)
Receiving corticosteroids (%)           68            63
Methotrexate dose (mg/wk)               17.5 (9.1)    15.0 (8.3)

Values are given as median (SD). HAQ denotes Health Assessment
Questionnaire and RF rheumatoid factor.
(a) On this scale, 0 is best and 10 worst.
(b) On this scale 0 is no difficulty and 3 is unable to perform
activity.

Table 2. Effect of treatment on measures of disease activity at six
months

                               Placebo +     Levofloxacin +
                               Methotrexate  Methotrexate
Measure of activity no. (%)    (n = 38)      (n = 38)        P value (a)

Swollen-joint count            15 (4)         8 (2)          <0.001
Tender-joint count             23 (6)        10 (3)          <0.001
Morning stiffness (hr)          4.3 (1.4)     1.3 (0.9)      <0.005
Physician's assessment (b)      6.1 (1.4)     2.4 (0.7)      <0.001
Patient's assessment (b)        6.4 (2.6)     3.1 (1.3)      <0.001
Pain (VAS) (b)                  6.1 (1.9)     2.2 (0.6)      <0.001
HAQ (c)                         1.61 (0.5)    1.21 (0.3)     <0.001
ESR (mm/h)                     49 (24)       19 (12)         <0.001
CRP (mg/dL)                     2.9 (2.1)     0.5 (0.3)      <0.001
Improvement from baseline (%)
  Swollen-joint count          17            68              <0.001
  Tender-joint count           21            60              <0.001

Values are given as median (SD).
(a) P values obtained from an analysis of variance.
(b) On this scale, 0 is best and 10 worst.
(c) On this scale, 0 is no difficulty and 3 is unable to
performactivity.
VAS, visual analog scale; ESR, erythrocyte sedimentation rate; CRP, C-
reactive protein; HAQ, Health Assessment Questionnaire.

Table 3. Efficacy at six months according to the ACR response rate
criteria

                   Placebo +     Levofloxacin +
                   Methotrexate  Methotrexate
Variable           (n = 38)      (n = 38)

ACR response rate
  ACR 20           18.4%         57.9% (a)
  ACR 50            7.9%         34.2% (a)
  ACR 70            2.6%         18.4% (a)

The P values were obtained by chi-square test comparing treatment
groups.
(a) P < 0.001

Table 4. Adverse events

                                  Placebo +     Levofloxacin +
                                  Methotrexate  Methotrexate
Adverse event, no. (%)            (n = 38)      (n = 38)

Death                             0             0
Serious adverse events
  Related to study drug           0             0
Most frequent adverse events (a)
  Gastrointestinal pain           2 (5.3)       6 (15.6) (b)
  Nausea                          5 (13.2)      6 (15.6)
  Vomiting                        3 (7.9)       3 (7.9)
  Diarrhea                        2 (5.3)       3 (7.9)
  Headache                        6 (15.6)      7 (18.4)
  Dry mouth                       2 (5.3)       3 (7.9)

(a) Rheumatoid arthritis was not included.
Fisher exact tests: (b) P < 0.05.