Data Availability StatementNo datasets were generated or analysed during the current study. patients had to discontinue the therapy due to clinical persistence and the third due to lymphoma progression. Intradermal tests with 0.1% rituximab were positive in only 20% of cases, demonstrating a mechanism of hypersensitivity. em Conclusions /em . The 12-step desensitization protocol is very effective and assumable within healthcare practice. There is a need to determine the mechanism underlying the infusion reaction in a large proportion of cases due to the risk of future drug exposure. 1. Introduction Rituximab is a murine/human chimeric monoclonal antibody against CD20 that has been in use for more than 20 years for the treatment of B-cell lymphomas and autoimmune disorders . Currently, new monoclonal antibodies against humanized CD20 are replacing rituximab for several of its indications [2, 3] and are associated with fewer infusional adverse reactions; however, these new options are not IKK 16 hydrochloride affordable in many countries. Rituximab improves overall survival and progression-free survival in the majority of B-cell lymphomas and is therefore part of all therapeutic regimens. Therefore, its elimination due to hypersensitivity reactions is detrimental to patients. The main reasons for IKK 16 hydrochloride eliminating rituximab from the therapeutic protocol of lymphoma patients are severe infusion reactions (IRs) that do not remit after subsequent administrations and corrective measures. Infusion-related adverse reactions have been reported in 84C95% of cases, but 90% of cases are mild . IRs are dose-dependent and, in the case of lymphomas, closely related to tumour burden, and thus, they are limited to the first-line administration. The most frequent aetiologies are cytokine release syndrome (CRS), tumour lysis syndrome (TLS), and hypersensitivity reactions (HSRs) . HSRs can occur after various exposures to the drug, and an IgE mechanism can be demonstrated in some cases. The symptoms can be indistinguishable from those described in TLS and CRS, with the difference being that they persist despite the control of the IKK 16 hydrochloride tumour burden. The clinical picture is characterized by the presence of pruritus, urticaria, tightness in the chest, nausea, vomiting, or diarrhoea after various infusions, which can progress to anaphylaxis or anaphylactic shock . Administration protocols adapted to numerous chemotherapeutic agents have been successful in achieving administration of the drug in question. The most commonly used is the 12-step protocol initially explained IKK 16 hydrochloride for carboplatin desensitization  but since prolonged to other providers. 2. Objectives In the present study, we describe the results of the intradermal hypersensitivity test to assess a possible IgE-mediated HSR in individuals that received intravenous rituximab in the context of B-cell lymphoma following a 12-step desensitization protocol. 3. Methods Individuals from December 2014 to December 2017 with medical symptoms of IR during and after receiving rituximab monotherapy or in association with B-cell lymphoma treatment were prospectively and consecutively included in the desensitization institutional protocol, which is definitely more frequently utilized for carboplatin desensitization. Candidates regarded as for the desensitization protocol were those individuals with severe IR, and all exhibited repeated IR with subsequent rituximab doses despite having taken more intense preventive actions (slower infusion, higher corticosteroid, and antihistamine doses). The IR severity grade was classified relating to Common Terminology Criteria for Adverse Events version 4.0. The prospective dose of rituximab was determined separately. All individuals received premedications: corticosteroids (80C100?mg/day time of TP53 methylprednisolone), antihistamines, and antipyretics. A desensitization protocol was founded, with 3 solutions given in 12 methods  (Table 1). Infusion was started with the 1st remedy (dilution 1/100) at 2?ml/h, and the rate was doubled every 15?min (methods 1C4). Second, a dilution of 1/10 was given at an initial velocity of 5?mL/h for methods 5C8. Third, a solution at the standard concentration was given at 10?mL/h, and the rate was then doubled every 15?min (methods 9C12). An.