Evaluasi Pemeriksaan Imunoglobulin E Spesifik Menggunakan Immunoblot Assay dengan Baku Emas Skin Prick Test

Abstract

Pendahuluan. Skin Prick Test (SPT) merupakan baku emas diagnosis alergi, tetapi tidak dapat dilakukan pada kondisi tertentu seperti dermatografisme, hamil, tidak dapat lepas obat antialergi, sehingga pemeriksaan IgE spesifik menjadi pilihan. Di Indonesia belum ada data perbandingan pemeriksaan IgE spesifik dengan SPT. Penelitian ini dilakukan untuk menentukan sensitivitas, spesifisitas, PPV, NPV, LR+ dan LR- pemeriksaan IgE spesifik menggunakan analisis immunoblot. Metode. Penelitian menggunakan desain potong lintang. Subjek penelitian adalah pasien poliklinik alergi imunologi. Pengambilan sampel dengan metode non-probability sampling dengan teknik consecutive sampling. Analisis dilakukan terhadap alergen tungau debu rumah (Dermatophagoides pteronyssinus, Dermatophagoides farinae, Blomia tropicalis) dan kecoa. Hasil. Seratus subjek yang memenuhi kiteria masukan dan tolakan (76% perempuan, rerata usia 38.9 tahun) ikut serta dalam penelitian ini. Sensitivitas empat alergen bervariasi dengan rentang 32.4%-76.8%, spesifisitas 68.0%-85.7%, PPV 54.5%-94.5%, NPV 46.2%-65.3%, LR+ 1.8-5.0, dan LR- 0.3-0.8.Sensitivitas pemeriksaan IgE spesifik cukup baik pada tiga tungau debu rumah tetapi rendah pada kecoa; spesifisitas dan PPV bervariasi cukup sampai baik; NPV cukup baik. Simpulan dan Saran. Uji diagnostik IgE spesifik tungau debu rumah menunjukkan hasil cukup baik. Pemeriksaan IgE spesifik tidak dapat digunakan untuk skrining alergi kecoa.

Background. Skin Prick Test (SPT) is considered as gold standard for diagnosis of allergy, but cannot be performed in some conditions such as dermatographism, pregnancy, and unable to abstain from antiallergy drugs. In these conditions, specific-IgE test is a test of choice. But there is no comparison data on specific IgE test with SPT in Indonesia. This study was to investigate sensitivity, specificity, PPV, NPV, LR+, and LR- of specific-IgE test of immunoblot assay kit. Method. The study was cross-sectional. Subjects were patients from allergy-immunology clinic who fulfilled inclusion and exclusion criteria. Sampling was performed using non-probability sampling method with consecutive technique. Analysis was performed for house dust mite allergen (Dermatophagoides pteronyssinus, Dermatophagoides farinae, Blomia tropicalis) and cockroach. Result. Hundred subjects (76% was female, average age of 38.9 years) were involved. Sensitivity of four allergens were varied with range 32.4%-76.8%, specificity 68.0%-85.7%, PPV 54.5%-94.5%, NPV 46.2%-65.3%, LR+ 1.8-5.0, and LR- 0.3-0.8. Sensitivities of specific-IgE for three species of house dust mite were moderate, but low for cockroach; specificities and PPVs were moderate to high; NPVs were moderate. Conclusion. Diagnostic test of specific-IgE with house dust mite allergen shows adequate result. Specific IgE test cannot be utilized for screening of cockroach allergy.