Background: Ovarian carcinoma serous subtype has a better prognosis than non-serous. Interferon gamma (IFN-γ) has a role in prognostic of ovarian carcinoma. IFN-γ may have both pro-tumor and anti-tumor activity. There is lack of evidence in determining IFN-γ level in ascites and its relationship with serous and non-serous.Objective: To determine the difference of IFN-γ level in ascites in serous and non-serous subtype of ovarian carcinoma. Methods:The study design was a cross-sectional. Ascites was taken intraoperatively from 11 samples of serous and 7 non-serous ovarian carcinoma patients underwent staging or debulking surgeries from September -December 2018. Ascites were evaluated using ELISA. Result:The mean of serous ascites IFN-γ level was lower (0.46±0.35 pg/ml (mean±SD)) than non-serous (0.97±0.88 pg/ml (mean±SD)), but there is no statistically significant (p = 0.104). Conclusion:There is no significant difference of IFN-γ level in ascites on serous and non-serous subtypes of ovarian carcinoma. ABSTRAKLatar Belakang: Karsinoma ovarium dapat dibedakan menjadi subtipe serosa dan non-serosa, dimana subtipe serosa memiliki prognosis yang lebih baik. IFN-γ dapat memiliki aktivitas pro-tumor maupun anti-tumor. Penelitian tentang kadar IFN-γ asites serta hubungannya dengan subtipe serosa dan non-serosa belum banyak dilakukan.Tujuan: Mengetahui perbedaan rata-rata kadar IFN-γ cairan asites pada subtipe serosa dan non-serosa karsinoma ovarium. Metode:Penelitian cross sectional selama periode September -Desember 2018. Pengambilan sampel asites dilakukan di kamar operasi RSUP Dr. Sardjito dan pengujian sitokin menggunakan Human IFN-γ ELISA Kit dilakukan di Laboratorium Biologi Molekuler FKKMK Universitas Gadjah Mada.Hasil dan Pembahasan: Pada 11 sampel subtipe serosa didapatkan rata-rata kadar IFN-γ sebesar 0,46 pg/ml, sedangkan pada 7 sampel non-serosa didapatkan rata-rata 0,97 pg/ml, namun perbedaan rata-rata tersebut tidak signifikan secara statistik (p=0,104). Simpulan: Tidak terdapat perbedaan rata-rata kadar IFN-γ dalam cairan asites pada subtipe serosa dan non-serosa karsinoma ovarium.Kata Kunci: interferon gamma (IFN-γ), karsinoma ovarium, asites, subtipe histopatologi ARTIKEL PENELITIAN