Basophil activation test in interstitial nephritis. Some comments

摘要

The recent paper by Lara Belmar Vega and coworkers intro- duced the role of a CD123 pos /HLADR neg basophil activation test (BAT) in a case report of interstitial nephritis, suggesting the occurrence of an interstitial nephropathy secondary to the use of omeprazole. 1 Omeprazole is well known from past reports to cause interstitial nephritis. 2 The renal oedematosus interstitium having a massive infiltration of leukocytes and eosinophils, suggested the author to assess an immune response, due to the omeprazole therapy. This case report should assess the optimal use of BAT in omeprazole hypersensitivity. 3 Despite the fact that the authors were not endowed with further allergic tests, such as skin prick test (SPT) or serum IgEs to assess their evidence, they moved on the clinical suspicion of an allergy-driven nephropathy caused by an hypersensitivity response to omeprazole and found a CD63 stimulation index (SI) ≥4.1 and ≥10% respect the basal, non activated level. 1 The analytical performance of a BAT based on the CD123 pos /HLADR neg gating protocol allowed the authors to easily capture basophils in a flow cytometry (FC) approach and to assess cell activation by evaluating the CD63 membrane upregulation upon the activation from omeprazole-caused drug hypersensitivity. Yet, the activation is only slightly higher (i.e. 10.25%) than the indicated cut off, which is ≤5% and did not reach the much more encouraging level of an fMLP-mediated activation (34.9%).