Homocysteine plasma levels in patients affected by hidradenitis suppurativa: an Italian experience

Hidradenitis suppurativa (HS) is a chronic, inflammatory, recurrent and debilitating skin disease, which is frequently associated with other systemic conditions.1 In particular, several studies have suggested that patients with HS have a higher cardiovascular risk compared with healthy controls (HCs).2 It was also recently shown that an increase of 5 μmol/L in plasma homocysteine was associated with a 60% higher prevalence of ischaemic heart disease.3 4 We carried out a study to evaluate the correlation between homocysteinaemia and HS to allow early identification of cardiovascular risk among patients under study. This was a prospective, nonrandomized, case–control study. The study was approved by the local ethics committee and carried out in accordance with the principles of the Declaration of Helsinki. All participants provided signed informed consent. In total, 26 consecutive outpatients attending the Dermatology Department (University Hospital Federico II, Naples, Italy) from October 2016 to November 2017 were recruited to the case group. Inclusion criteria were: age ≥ 18 years, diagnosis of HS ≥ 6 months before study initiation; no therapy for at least 4 months prior to study enrolment. Exclusion criteria included a history of cardiovascular event; body mass index (BMI) > 30, presence of diabetes mellitus, chronic kidney disease, or another concomitant inflammatory or metabolic condition, and smokers with vitamin deficiencies. Disease severity was evaluated by Hurley score, Sartorius score and the six‐point Physician Global Assessment (HS‐PGA). The HC groups consisted of 26 age‐ and sex‐matched healthy individuals. The subjects avoided participating in strenuous exercise or becoming fatigued within 24 h before blood sampling, and were required to fast for 12 h before venous blood samples were taken. Plasma homocysteine concentration was determined by chemiluminescent microparticle immunoassay (CMIA). The cutoff point for hyperhomocysteinaemia was set at plasma levels >15 μmol/L, based on the normal range of homocysteine (5–15 μmol/L). Data were analysed using GraphPad Prism (GraphPad Inc., La Jolla, CA, USA). The individual parameters were expressed as mean ± SD. The analysed variables were compared between groups of patients selected by the use of multivariate statistical analysis one‐way ANOVA nonparametric tests (Mann–Whitney test), and Spearman correlation test was used to evaluate the relationship between analysed variables. P < 0.05 with 95% CI was considered statistically significant. The case group consisted of 26 patients with HS (15 women, 9 men; mean age 32 years, range 18–52 years), and the HC group also consisted of 26 people (16 women, 8 men; mean age 31.1 years (range 18–55 years). Mean Sartorius score for the patients was 60.1 ± 10.55; 8 patients were evaluated as grade 3 and 18 patients as grade 2 according to Hurley score. The mean plasma levels of homocysteine in patients with HS (mean 16.71 ± 10.17) were significantly higher than the control group (12.96 ± 8.16) (P = 0.048; Fig. 1). As we expected, there was a significant overlap in homocysteine plasma levels among the patients under study. Moreover, we found a statistically significant correlation between the plasma levels of homocysteine and disease severity evaluated using Sartorius score (P < 0.01; r = 0.55) (Fig. 2). Similar data were previously found for patients with psoriasis, who also expressed higher levels of plasma homocysteine than HCs.5 Homocysteine plasma levels in patients with hidradenitis suppurativa (HS) vs. healthy controls. Plasma levels of homocysteine and disease severity (Sartorius score). In conclusion, we found a significant increase in plasma homocysteine in patients with HS, which correlated with disease severity, and was in line with a similar increase reported previously for patients with psoriasis. The study was limited by its small sample size, and further studies with large groups are needed to verify these preliminary results. Conflict of interest: the authors declare that they have no conflicts of interest.