Secukinumab decreases serum Krebs von den Lungen 6 (KL-6) level in patients with psoriasis with elevated serum KL-6 level

Real-world blood examination screening data before initiation of biologics for psoriasis patients

Psoriasis is a chronic immune-mediated inflammatory skin disease characterized by hyperproliferation of epidermal keratinocytes. Biologics have been available for the treatment of patients with refractory psoriasis since 2010 in Japan, and as of December 2021, 10 biologics were available. The Biologics Review Committee of the Japanese Dermatological Association for Psoriasis recommends blood examination tests for antinuclear antibodies (ANA), Krebs von den Lugen (KL)-6, hepatitis B surface antigen (HBsAg), hepatitis B surface antibodies (HBsAb), hepatitis B core antibodies (HBcAb), hepatitis C virus (HCV) antibodies, HIV antibodies, human T-cell leukemia virus (HTLV)-1 antibodies, β-D-glucan, and the T-cell spot (T-SPOT) test before initiation of biologics at screening. In this study, we evaluated the use of biologics for 127 psoriasis patients and the blood examination screening data before initiation of biologics in the real-world setting. Tumor necrosis factor inhibitors, interleukin (IL)-17 inhibitors and IL-23 inhibitors were initiated for 54 (42.5%), 36 (28.3%), and 37 (29.1%) patients, respectively. The numbers of patients positive for ANA, HBsAg, HBsAb, HBcAb, HCV antibody, HIV antibody, HTLV-1 antibody, and T-SPOT were 27 (21.3%), 0 (0%), 22 (17.3%), 20 (15.7%), three (2.4%), zero (0%), one (0.8%), and 4 (3.1%), respectively. The numbers of patients whose KL-6 and β-D-glucan levels were higher than the reference values were seven (5.5%) and seven (5.5%), respectively. In the real-world setting, it is sometimes unavoidable to use biologics for those patients with abnormal data although careful monitoring is necessary.

Effect of anti-interleukin-17 biologics on Krebs von den Lungen-6 level in patients with psoriasis

Interleukin (IL)-17 plays critical roles in the pathogenesis of both psoriasis and interstitial pneumonia (IP). We hypothesized that anti-IL-17 biologics might suppress both clinically relevant and latent IP activity and decrease Krebs von den Lungen-6 (KL-6) level in psoriasis patients. We aimed to elucidate the effects of anti-IL-17 biologics on KL-6 levels. We retrospectively analyzed the clinical data of psoriasis patients treated with anti-IL-17 biologics. KL-6 levels were measured before treatment (baseline) and at 3 and 6 months after the initiation of the treatment, and ratios of KL-6 levels at each time point to the baseline levels were calculated. Chest computed tomography (CT) was performed on patients with coexisting IP. The clinical characteristics and radiographic findings were evaluated. A total of 294 psoriasis patients were treated with anti-IL-17 biologics. Baseline KL-6 levels were higher than 401 U/mL in 34 patients (high baseline KL-6 group). While anti-IL-17 biologics did not affect KL-6 levels and ratios of KL-6 to the baseline levels at any time point in the overall study population, they decreased both KL-6 levels and ratios at 6 months after the initiation of the treatment in the high baseline KL-6 group. A total of 10 patients with coexisting IP showed decreasing ratios of KL-6 to the baseline levels at 6 months without affecting coexisting IP in CT performed at 3-12 months. Anti-IL-17 biologics decreased KL-6 levels in the high baseline KL-6 group regardless of recognizable IP. A decrease in KL-6 levels was not associated with a radiographic improvement of IP, which should be examined in large numbers with long-term observations in future studies.

Serum Krebs von den Lungen-6 levels in psoriatic patients under treatment with biologics

During biologic treatments, attention should be paid to adverse reactions, particularly infectious diseases. Furthermore, drug-induced interstitial lung disease is also known to be associated with biologic therapies. We retrospectively reviewed serum Krebs von den Lungen-6 (KL-6) levels in psoriatic patients who underwent treatment with seven different biologics. A total of 67 patients who received 80 biologic treatments were evaluated. The 31 anti-tumor necrosis factor (TNF)-α treatments consisted of 17 infliximab (IFX) and 14 adalimumab. The 23 anti-interleukin (IL)-23 treatments consisted of 14 ustekinumab and nine guselkumab. The 26 anti-IL-17 treatments consisted of nine secukinumab, six ixekizumab and 11 brodalumab. The IFX showed significantly increased mean serum KL-6 (170.9%), but none of the other treatments showed significant increases. Thirteen of the 17 (75.6%) patients in the IFX and 17 of the 31 (54.8%) patients in the total anti-TNF-α group demonstrated at least a 25% increase in serum KL-6. Levels exceeding the cut-off (500 U/mL) were detected in three patients before treatment and in seven patients after treatment. This study showed that anti-IL-17 and anti-IL-23 treatments have no significant impact on serum KL-6 level. In addition to the influence of IFX, a significantly large number of patients in the IFX group had a history of methotrexate administration associated with psoriatic arthritis, which might have influenced the KL-6 level. None of the patients with elevated serum KL-6 showed pulmonary changes by computed tomography and/or X ray.