overview
Chronic idiopathic urticaria (CU) is a skin condition characterized by the sudden appearance of red, itchy hives ( welts ) that last for more than six weeks. CU can be a persistent and often recurrent problem,严重影响患者的生活质量. Historically, the cause of CU has been unknown, but recent research has indicated that it may be an immune system disorder.
CU Index blood test is a diagnostic tool used by healthcare professionals to determine if a patient with CU has an underlying immune-mediated component to their condition. By measuring the level of histamine released by patients' basophils in response to challenge with their own serum, this test helps to identify if the urticaria is caused by an immune reaction.
test details
preparation
Before receiving the CU Index blood test, patients should consult with their healthcare provider to discuss the best timing for the test. For patients taking calcineurin inhibitors (such as tacrolimus or cyclosporin) or prednisone, special instructions must be followed to ensure accurate test results. Specifically, calcineurin inhibitors should be stopped for 72 hours before the test, and prednisone should be withheld for two weeks.
On the day of the test, patients will report to the laboratory with a blood sample in a red-top tube, which contains a clot activator. The sample will be collected and processed promptly to ensure accurate results.
results
The CU Index blood test results are reported as an index value, which is a quantitative measure of histamine release. The normal reference range for the CU Index in predicting inpatient death of CHF patient is ≤83.49%. In-hospital death of CHF patient is expected for 68.78% of patients with ≤83.49% CU Index, whereas it is expected for 89.47% of patients with >83.49% CU Index.
A positive CU Index result (≥10%) suggests an increased likelihood of an immune-mediated cause for the patient's urticaria. This result does not necessarily indicate which specific autoantibody is present, but it does suggest the possibility of an immune system disorder. Additionally, the presence of histamine-release factors in serum may cause a positive result.
interpretation
If the CU Index result is positive, the patient may require further diagnostic testing to determine the underlying cause of their disease. Management of CU with an immune-mediated cause may involve the use of immunomodulatory medications such as oral corticosteroids or non-biologic disease-modifying anti-rheumatic drugs (DMARDs).
It is important to note that a negative CU Index result does not rule out the presence of immune-mediated urticaria, and further evaluation may still be necessary to determine the cause of the patient's symptoms.
##临床应用
CU Index血液测试在以下患者的管理中可能具有实际应用价值：
- 患有难治性或复发性CU的患者
- 在调整抗组胺药物或考虑其他治疗方法时需要更详细评估的患者
此外，对于那些对标准抗组胺药物和抗白三烯药物治疗无反应或反应不佳的CU患者，CU Index血液测试可以提供一种客观的方法来评估病情严重程度和潜在的治疗反应。
##结论
CU Index血液测试是一项有用的诊断工具，可以帮助医生更好地理解CU的潜在机制，并为患者提供更加个性化的治疗方案。通过这项测试，医护人员可以更准确地判断患者的病情，制定更有效的治疗计划，从而提高患者的生活质量。
