Immune Markers May Flag Which Psoriasis Patients Respond Best to Ustekinumab

Chinese researchers have identified two immune markers that appear to track how well patients with plaque psoriasis respond to the biologic drug ustekinumab, according to a retrospective single-center study published in BMC Genomic Data. Patients carrying the HLA-C*06:02 allele and those with elevated baseline levels of serum total immunoglobulin E, or IgE, showed measurably better skin clearance on the drug than patients without these features, although the authors stress the findings are exploratory and require validation.

A single-center retrospective study enrolled 42 Chinese patients with plaque psoriasis, who received ustekinumab at weeks 0, 4, 16 and 28. The researchers performed genome-wide microarray analysis and assessed clinical data for all participants, tracking skin improvement using PASI 50, PASI 75 and PASI 90 thresholds, which correspond to 50, 75 and 90 percent reductions in disease severity.

In this cohort, the presence of HLA-C*06:02 appeared to influence the speed of response rather than the ultimate outcome. Patients positive for the allele achieved significantly higher PASI 50 response rates at week 4 and higher PASI 75 response rates at week 16 compared with patients who lacked it, with all reported differences reaching statistical significance. By week 28, every patient in both groups had reached PASI 75, meaning both genetic groups eventually achieved at least a 75 percent reduction in disease severity.

The PASI 90 response rate at week 28, the deepest clearance threshold measured, was numerically higher in the HLA-C*06:02-positive group, but the difference was not statistically significant. The authors also report that multivariate binary logistic regression analysis showed HLA-C*06:02 positivity was associated with achieving PASI 75 at week 16.

In this study, patients whose baseline total IgE exceeded 60 IU/mL showed superior PASI 75 response rates at weeks 4 and 16, and higher PASI 90 response rates at weeks 16 and 28, with all of these differences statistically significant. Unlike the genetic marker, the IgE signal extended to the deepest clearance threshold at both the mid-study and final time points, making it the stronger of the two associations at week 28 in this cohort.

Taken together, the results suggest that a combination of genetic testing and a routine blood measurement could eventually help clinicians anticipate which patients are likely to clear their skin quickly on ustekinumab. The authors frame the work as an association study in a modestly sized cohort, not a predictive test, and their conclusion explicitly notes that the findings are exploratory and require validation.

Several limitations follow directly from the study design. A retrospective, single-center analysis of 42 patients cannot establish that either marker causes better drug response, and the small sample size limits the precision of the estimates. All participants were biologic-naive Chinese patients, so the results may not generalize to patients who have already received other biologics or to populations with different genetic backgrounds.

For patients and clinicians, the practical takeaway is cautious. Neither HLA-C*06:02 status nor baseline IgE should currently guide treatment decisions outside a research setting, since no validated prospective cohort has confirmed these associations. What the study does establish is that, in this Chinese cohort, both markers were measurable before treatment and correlated with the pace and depth of skin clearance over 28 weeks of ustekinumab therapy. Larger, prospective, multi-center studies in diverse populations would be needed before either marker could enter routine clinical use as a predictor of biologic response in plaque psoriasis.

Subject of Research: Association of the HLA-C*06:02 allele and serum total IgE with ustekinumab response in biologic-naive Chinese patients with plaque psoriasis.

Article Title: Association of HLA-C*06:02 allele and serum total IgE level with therapeutic response to Ustekinumab in Biologic-Naive Chinese patients with plaque psoriasis: a single-center retrospective study

Article References: Bai, F., Yang, Y., Miao, G., Yu, W., Xu, Y., Wang, L., Cheng, X., & Lei, M. (2026). Association of HLA-C*06:02 allele and serum total IgE level with therapeutic response to Ustekinumab in Biologic-Naive Chinese patients with plaque psoriasis: a single-center retrospective study. BMC Genomic Data. https://doi.org/10.1186/s12863-026-01497-5

Image Credits: AI Generated

DOI: 10.1186/s12863-026-01497-5

Keywords: psoriasis, ustekinumab, HLA-C*06:02, immunoglobulin E, biologic therapy, PASI response, pharmacogenomics, retrospective study, interleukin-12, interleukin-23, BMC Genomic Data, treatment response