Hydroxychloroquine exerts favourable effects on lipid profiles in lupus patients
Hydroxychloroquine (HCQ) provides significant immunomodulatory benefits to patients with systemic lupus erythematosus (SLE), with a study showing that the drug is associated with a mean reduction of 24.397 mg/dL in serum low-density lipid level.
Researchers conducted a systematic review and meta-analysis of two before-after studies and six case-control studies examining the effects of HCQ on serum low-density lipoprotein (LDL) cholesterol level.
The pooled study population comprised 559 SLE patients (mean age 45.72 years; 95.26 percent female; 58.37 percent prednisolone users). HCQ was found to reduce mean LDL levels by 24.397 mg/dL (95 percent CI, 8.921 to 39.872; p=0.002).
With regard to statin use, the number of studies identifying statin users was too few to allow performance of meta-regression analysis.
Extensive heterogeneity was noted among the studies (I2, 94.74 percent), while visual inspection of funnel plots revealed no evidence of publication bias.
The favourable effects of HCQ on lipid profiles have been hypothesized through different mechanisms. First, chloroquine affects the cholesterol biosynthetic pathway outside of the cytosolic acetylcoA, inhibiting the enzymatic step catalyzed by 2,3-oxidosqualene-lanosterol cyclase and consequently halting the synthesis of an intermediate in cholesterol biosynthesis, lanoesterol. Second is the upregulation of LDL receptors, contributing to reductions in serum LDL levels. Third, HCQ targets endosomal nicotinamide adenine dinucleotide phosphate oxidase, which plays a role in many inflammatory and prothrombotic signalling pathways. [Ann Rheum Dis 2017;76:891–7]
Despite the study limitations, including the heterogeneity of the findings and the inability to adjust for confounding factors, researchers pointed out that the clinical implications of the lipid-lowering effects of HCQ should be highlighted in preventative healthcare for the population of SLE patients.
Furthermore, current cardiovascular risk models should be adjusted for patients with lupus and other autoimmune disorders, researchers added.