Hydroxychloroquine Whole Blood Levels Do Not Associate with Hydroxychloroquine Retinopathy

Michelle Petri¹, Wei Fu² and Syed Mahmood Shah³, ¹Rheumatology Division, Johns Hopkins University School of Medicine, Baltimore, MD, ²Rheumatology, Johns Hopkins University School of Medicine, Baltimore, MD, ³Johns Hopkins University School of Medicine, Baltimore, MD

Meeting: 2016 ACR/ARHP Annual Meeting

Date of first publication: September 28, 2016

Keywords: Hydroxychloroquine, ocular involvement and systemic lupus erythematosus (SLE)

Session Information

Date: Sunday, November 13, 2016

Title: Systemic Lupus Erythematosus – Clinical Aspects and Treatment - Poster I: Clinical Trial Design and Current Therapies

Session Type: ACR Poster Session A

Session Time: 9:00AM-11:00AM

Background/Purpose: The American Academy of Ophthalmology guidelines on hydroxychloroquine retinopathy were recently revised (Ophthalmology 2016;1-9). These guidelines recommend optical coherence tomography (OCT) with multifocal electroretinogram (mfERG) and fundus autoflorescence (FAF) as corroboratory tests. These tests can be subject to interpretation differences and require validation and repeat testing. Whether hydroxychloroquine blood levels predict retinopathy is currently unknown.

Methods: SLE patients on hydroxychloroquine underwent screening with OCT, mfERG and FAF. Hydroxychloroquine retinopathy, possible or definite, was determined by retina specialists. Patients had hydroxychloroquine blood levels (Clarke et al) determined at every clinic visit.

Results: Among the 117 patients, 95.7% were female; 50% Caucasian and 44% African-American. 12 had definite and 7 possible hydroxychloroquine retinopathy. 83.8% had no hydroxychloroquine retinopathy. Table 1: HCQ Retinopathy by HCQ Blood Level

Highest HCQ level (ng/mL)	No toxicity N (%)	Possible Toxicity N (%)	confirmed toxicity N (%)	Total
Greater than 2,000	25 (83.3)	2 (6.7)	3 (10.0)	30
1,500 to 1,999	23 (79.3)	4 (13.8)	2 (6.9)	29
1,000 to 1,499	30 (85.7)	1 (2.9)	4 (11.4)	35
500 to 999	13 (100)	0 (0)	0 (0)	13
Less than 499	7 (70.0)	0 (0)	3 (30.0)	10

Pair-wise comparison using t test with pooled Standard deviation showed that the average highest HCQ levels were not significantly different among the three groups (No vs. Possible vs. Yes) After grouping those with “confirmed” and “possible” toxicity, the average highest HCQ level was 1511.6 ng/mL vs 1591.1 ng/mL in those with vs. without retinopathy. The difference between these two groups is not significant (P = 0.7094) using t test.

Conclusion: We confirm a much higher frequency of hydroxychloroquine retinopathy (when defined by preclinical testing) than expected based on previous reports. Some SLE patients have high hydroxychloroquine levels, while on appropriate dosing by real weight. This does not correlate with current hydroxychloroquine retinopathy. Further followup will be able to prove if hydroxychloroquine blood levels predict future retinopathy.

Disclosure: M. Petri, None; W. Fu, None; S. M. Shah, None.

To cite this abstract in AMA style:

Petri M, Fu W, Shah SM. Hydroxychloroquine Whole Blood Levels Do Not Associate with Hydroxychloroquine Retinopathy [abstract]. Arthritis Rheumatol. 2016; 68 (suppl 10). https://acrabstracts.org/abstract/hydroxychloroquine-whole-blood-levels-do-not-associate-with-hydroxychloroquine-retinopathy/. Accessed .

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