The autologous serum skin test (ASST) predicts the response to anti-IgE treatment in Chronic Spontaneous Urticaria patients: a prospective study
Andrea Palladino
1,2, Francesca Villani
1, Elena Pinter
3, Marcella Visentini
1, Riccardo Asero
r.asero@libero.it4Show more: Authors information and Publication history1Department of Translational and Precision Medicine, Sapienza University of Rome, Rome, Italy
2Internal Medicine Unit, Santa Maria Goretti Hospital, Latina, Italy
3UOC Immunologia Clinica, Policlinico Umberto I, Roma, Italy
4Allergology Clinic, Clinica San Carlo, Paderno Dugnano, Milan, Italy
HistoryPublished: 14 March 2024
Accepted: 11 March 2024
Received: 08 January 2024
Doi10.23822/EurAnnACI.1764-1489.337SummaryBackground. Chronic spontaneous urticaria (CSU), characterized by recurrent itchy wheals and angioedema for > 6 weeks, is a quite common disease that may heavily impair the quality of life. Omalizumab, an anti-IgE mAb, has much improved the management of CSU but patients' response to the drug may vary and predictive markers are still largely missing. We investigated the predictive value of the autologous serum skin test (ASST) on omalizumab response.
Methods. 15 patients with severe CSU eligible for omalizumab treatment were prospectively studied submitting them to ASST and to complete blood count, D-dimer, anti-thyroid peroxidase antibodies, and total IgE measurement before the start of the treatment.
Results. 14/15 (93%) responded brilliantly to omalizumab at 3 months assessment. 7 responded in less than 1 month ("early responders") and 7 only after multiple administrations ("late responders"). Of 9 patients scoring positive on ASST, 7 (78%) were late, and 2 (22%) early responders to omalizumab (p = 0.021). Of 6 patients scoring negative on ASST, 5 were early omalizumab responders and 1 did not respond. The PPV and NPV of the ASST for a "late" response to omalizumab were 78% and 100%, respectively. Total IgE were significantly higher in early responders.
Conclusions. Although larger prospective studies are needed to confirm these results, this study confirms previous retrospective investigations that the positive ASST appears to predict a slow response to omalizumab in CSU patients.
Key words
Chronic spontaneous urticaria (CSU); Autologous Serum Skin Test (ASST); omalizumab; IgE; endotype.
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