Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.


Low Blood Concentration of Hydroxychloroquine Is Associated with Failure of Hydroxychloroquine Treatment in Patients with Cutaneous Lupus: Results of a Prospective Study.

Frances1,  Camille, Cosnes1,  Anne, Duhaut2,  Pierre, Zahr3,  Noël, Soutou1,  Boutros, Oro1,  Saskia, Bessis1,  Didier

Department of Dermatology, Hôpital Tenon, Paris, France
Department of Dermatology, Hôpital Tenon
Internal Medicine Department, French National Reference Center for SLE, Pitié-Salpêtrière Hospital (GHPS), Paris, France

Introduction:

We have previously demonstrated that low whole-blood concentration of Hydroxychloroquine [HCQ] is a marker for and a predictor of disease exacerbations in SLE patients, and we proposed 1,000 ng/ml as the target [HCQ] (Costedoat-Chalumeau, Arthritis Rheum, 2006). Very low [HCQ] (i.e. [HCQ] < 200 ng/ml) is a marker for poor adherence to HCQ treatment (Costedoat-Chalumeau, Ann Rheum Dis, 2007).

We studied for the first time, the relationship between [HCQ] and efficacy of HCQ in patients with cutaneous lupus.

Methods:

Patients treated with HCQ for a cutaneous lupus were prospectively included in this multicentric study. Clinical status was determined by a dermatologist who was blinded for [HCQ]. Complete remission was defined by the disappearance of all cutaneous lesions, partial remission by an improvement > 50% and failure by other cases. At the end of the study, [HCQ] was measured by HPLC.

Results:

We included 300 patients: 253 (84%) women and 47 (16%) men, median age 44 years [12–86]. Cutaneous lupus included discoid lupus (n=160), subacute cutaneous lupus (n=86), lupus tumidus (n=52), chilblain lupus (n=26), and panniculitis (n=16), and 41 patients had 2 or more associated forms. Most patients (83%) were treated with 400 mg/d of HCQ. Clinical status was complete remission (n=114), partial remission (n=86) or failure (n=100).

The median [HCQ] was 758 ng/ml [<50–3057]. [HCQ] was significantly higher in patients with complete remission (910 [<50–3057] vs 692 [<50–2843] if partial remission, and 569 [<50–2242] if failure; p=0.007).

[HCQ] was significantly lower in men (557 [<50–1572] vs 801 [<50–3057] in women; p = 0.006) who more frequently reported poor adherence to HCQ treatment (28% vs 11%; p = 0.002). [HCQ] correlated with the number of reported omissions of HCQ (p = 0.01).

Thirty patients (10%) had [HCQ] below 200 ng/ml and were considered as non-adherent. There were 8 patients in complete remission group, 8 in partial remission group, and 14 in failure group. Number of self-reported omissions of HCQ was significantly higher (p = 0.0001) in non-adherent patients.

After exclusion of non-adherent patients, [HCQ] was 850 ng/ml [201–3057] in the remaining 270 patients. [HCQ] remained significantly higher in patients with complete remission (952 [224–3057] vs 755 [212–2843] if partial remission and 692 [201–2242] if failure, p=0.026).

In the whole group, [HCQ] was significantly correlated to BMI (p = 0.02), weight (p = 0.002) and height (p = 0.05). There was no correlation between [HCQ] and cigarette smoking, daily dose of HCQ or number of omissions of HCQ.

In multivariate analysis, factors associated with complete remission were higher [HCQ] (p=0.005), and the absence of discoïd lesions (p=0.037). This remained true when analysis was performed after exclusion of non-adherent patients (p=0.01 and p=0.016 respectively).

Comment:

[HCQ] allowed detection of non-adherence to treatment in 10% of cases. Even after exclusion of non-adherent patients, low [HCQ] was associated with failure of HCQ treatment in patients with cutaneous lupus. Regular drug assaying and individual tailoring of treatment might help to improve the efficacy of HCQ treatment in patients with cutaneous lupus.

To cite this abstract, please use the following information:
Frances, Camille, Cosnes, Anne, Duhaut, Pierre, Zahr, Noël, Soutou, Boutros, Oro, Saskia, et al; Low Blood Concentration of Hydroxychloroquine Is Associated with Failure of Hydroxychloroquine Treatment in Patients with Cutaneous Lupus: Results of a Prospective Study. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :2238
DOI: 10.1002/art.30001

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