Odilon Marques de Almeida Filho

Chronic spontaneous urticaria: cutaneous reaction and laboratory aspects

Introduction: The chronic spontaneous urticaria (CSU) is a cutaneous reaction characterized by the formation of episodic and recurrent erythematous papules, usually pruritic, which etiology may be associated with an autoimmune response resulting from the action of immunoglobulin subclass G (IgG) of autoantibodies directed against the immunoglobulin subclass E (IgE) receptors of cutaneous mast cells or against IgE bound to mast cells. The autologous serum skin test (ASST) is a screening test that indicates the presence of these autoantibodies in patients with CSU. Objective: To check for differences in ASST results among patients with CSU and the control group with other hypersensitivities. Material and method: This is a cross-sectional case-control study, in which 49 adults were analyzed, 27 with CSU and 22 with other hypersensitivity reactions. ASST, CD123, estimation of IgG bound to basophil, mean platelet volume (MPV), antinuclear antibody (ANA), thyroid-stimulating hormone (TSH), anti-thyroid peroxidase antibody (TPOab), erythrocyte sedimentation rate (ESR) and the total IgE were performed in both groups. Results: The ASST, shown positive results in 16 (59.2%) the patients with CSU and in five (22.7%) from the control group, with statistical significance. For the other variables above described, there was no statistical difference. Conclusion: A higher ASST positivity was found in CSU patients compared to patients with other hypersensitivities, and further studies with larger sample are needed for better analysis of other variables.

Basophil Activation Test with Indomethacin to Assess Hypersensitivity to Non-Steroidal Anti-Inflammatory Drugs: A Preliminary Study

BACKGROUND The basophil activation test has been investigated for diagnosing hypersensitivity to non-steroidal anti-inflammatory drugs (NSAIDs). This has not yet been done in relation to indomethacin. OBJECTIVE First seek to establish the viable concentrations of indomethacin and the diluent propylene glycol (PPG) in relation to basophils then test this in patients with hypersensitivity to NSAIDs. MATERIALS & METHODS The ideal concentrations of PPG and indomethacin were assessed by incubating them with basophils from an atopic donor and evaluating the intensity of expression of CD63 molecules by means of flow cytometry. We also evaluated the cell viability directly using the trypan blue in seven controls. Then indomethacin was tested in ten patients with hypersensitivity to NSAIDs compared with eight persons in control group. RESULTS In relation to the toxicity of propylene glycol, concentrations less than or equal to 0.5% are safe. There was no cytotoxicity or nonspecific stimulation from using indomethacin at concentrations of 10 mcg/mL, 1 mcg/mL and 0.1 mcg/mL. Then indomethacin was tested at concentration of 10 mcg/mL diluted in 0.5% propylene glycol in both groups. There was no statistical difference in the intensity of activation of basophils comparing the group of patients with hypersensitivity to NSAIDs and the control group. CONCLUSIONS As a diluent for indomethacin, PPG should be used at concentrations less than or equal to 0.5%. The indomethacin at concentration of 10 mcg/mL was not able to differentiate patients with and without hypersensitivity to NSAIDs.

CD63 e CD123 expressão, autoanticorpos IgG e acurácia do teste do soro autólogo em pacientes com urticária crônica

INTRODUCTION: The autologous serum skin test (ASST) may suggest an autoimmune etiology in chronic urticaria (CU). A new laboratory technique called basophil activation test (BAT) has been currently employed for its diagnosis. OBJECTIVE: To analyze ASST in relation to BAT as well as to evaluate interleukin 3 (IL3) receptors (CD123) and non-specific immunoglobulin G (IgG) autoantibodies bound to basophils in patients with chronic urticaria. METHODS: We studied 33 adults with CU and mean age of 42.5 + 14 years. After stimulation by serum from patients with CU, CD63 expression on basophils from one atopic donor was analyzed by flow cytometry. Furthermore, we investigated CD123 and IgG autoantibody expressions. RESULTS: The odds ratio (OR) between ASST and BAT was 1.00 (95% confidence interval [CI]: 0.22 to 4.5). The ASST for autoimmune CU diagnosis showed an accuracy of 54.5%, sensitivity of 66%, specificity of 33%, positive predictive value of 63%, and negative predictive value of 36%. There was no statistical difference between the studied groups as to mean non-specific IgG and CD123 expressions (for a p < 0.05). DISCUSSION: This study demonstrated that ASST has low accuracy in the diagnosis of autoimmune CU. Concerning other analyzed aspects, there was no statistical difference between positive ASST and negative ASST. CONCLUSIONS: Due to insufficient studies in this area and the relevance of this issue, further investigation is required.