Factors predictive of leg-ulcer healing in sickle cell disease: a multicentre, prospective cohort study.

BACKGROUND: Leg ulcers (LUs) are a chronic and severe complication of sickle cell disease (SCD). A prospective study in patients with SCD to identify factors associated with complete healing and recurrence of LUs is lacking.

OBJECTIVES: To determine clinical and biological factors associated with SCD-LU complete healing and recurrence.

METHODS: This prospective, observational cohort study was conducted at two adult SCD referral-centre sites (2009-2015) and included 98 consecutive patients with at least one LU lasting ≥ 2 weeks. The primary end points compared patients with healed vs. nonhealed LUs at week 24, and patients with vs. without recurrence during follow-up.

RESULTS: The median (interquartile range) LU area, duration and follow-up were, respectively, 6·2 cm2 (3-12·8), 9 weeks (4-26) and 65·8 weeks (23·8-122·1). At week 24, LUs were healed in 47% of patients, while 49% of LUs recurred. Univariate analyses identified inclusion LU area < 8 cm2 (82% vs. 35%; P < 0·001), inclusion LU duration < 9 weeks (65% vs. 35%; P = 0·0013) and high median fetal haemoglobin level (P = 0·008) as being significantly associated with complete healing at week 24, and low lactate dehydrogenase level (P = 0·038) as being associated with recurrence. Multivariate analyses retained LU area < 8 cm2 (odds ratio 6·73, 95% confidence interval 2·35-19. 31; P < 0·001) and < 9 weeks' duration (OR 3·19, 95% confidence interval 1·16-8·76; P = 0·024) as being independently associated with healing at week 24. Factors independently associated with recurrence could not be identified.

CONCLUSIONS: SCD-LU complete healing is independently associated with the clinical characteristics of LUs rather than the clinical or biological characteristics of SCD.