MUM-1 immunohistochemistry has high accuracy and reliability in the diagnosis of chronic endometritis: a multi-centre comparative study with CD-138 immunostaining

Abstract

Purpose The current gold standard for chronic endometritis (CE) diagnosis is immunohistochemistry (IHC) for CD-138. However, IHC for CD-138 is not exempt from diagnostic limitations. The aim of our study was to evaluate the reliability and accuracy of MUM-1 IHC, as compared with CD-138. Methods This is a multi-centre, retrospective, observational study, which included three tertiary hysteroscopic centres in university teaching hospitals. One hundred ninety-three consecutive women of reproductive age were referred to our hysteroscopy services due to infertility, recurrent miscarriage, abnormal uterine bleeding, endometrial polyps or myomas. All women underwent hysteroscopy plus endometrial biopsy. Endometrial samples were analysed through histology, CD138 and MUM-1 IHC. The primary outcome was to evaluate the diagnostic accuracy of MUM-1 IHC for CE, as compared with CD-138 IHC. Results Sensitivity and specificity of CD-138 and MUM-1 IHC were respectively 89.13%, 79.59% versus 93.48% and 85.03%. The overall diagnostic accuracy of MUM-1 and CD-138 IHC were similar (AUC = 0.893 vs AUC = 0.844). The intercorrelation coefficient for single measurements was high between the two techniques (ICC = 0.831, 0.761-0.881 95%CI). However, among CE positive women, MUM-1 allowed the identification of higher number of plasma cells/hpf than .80] vs 5.05 [SD 3.37]; p = 0.017). Additionally, MUM-1 showed a higher inter-observer agreement as compared to CD-138. Conclusion IHC for MUM-1 and CD-138 showed a similar accuracy for detecting endometrial stromal plasma cells. Notably, MUM-1 showed higher reliability in the paired comparison of the individual samples than CD-138. Thus, MUM-1 may represent a novel, promising add-on technique for the diagnosis of CE.

Prevalence of chronic endometritis in unexplained implantation failure

“…This prospective, observational, analytical, cross-sectional study has been conducted on one hundred fifty women, who were affected by infertility and one or more unexplained implantation failures. The final results are as follow: Table ( Table (7) shows that, there is a highly significant relationship between residence and number of previous unexplained implantation failure, as 50/66 of the rural areas cases experienced RIF (P value 0.0012) Table (10) shows that, 89.3% of cases were without other abnormal findings during hysteroscopy as endometrial polyp, fine adhesions, or cervical stenosis.…”

“…In contrast, Kasius and coworkers [7] reported that the clinical implication of chronic endometritis seems minimal since they diagnosed this condition in 2% of asymptomatic infertile patients with a normal transvaginal ultrasound examination (TVS). The same author reported that the reproductive outcome at ICSI cycles was not negatively affected by chronic endometritis and that the low prevalence and unknown clinical significance of it warrants further study [7,12]. The aim of the study was to evaluate the effects of chronic endometritis on implantation failure at ICSI through its prevalence at hysteroscopy and histology, in a population of women who experienced implantation failure at ICSI.…”

“…One of the abnormalities, which cannot be detected with ultrasound and HSG, is chronic endometritis that is a subtle pathology often asymptomatic or only accompanied by mild disturbances. Histological identification of plasma cells in the endometrial stroma is considered the gold standard for the diagnosis [7], but due to the normal presence of leukocytes in the endometrium especially before menstruation, even histology may miss the diagnosis. Fluid hysteroscopy reliably diagnoses chronic endometritis based on the demonstration of specific signs such as micropolyps, stromal edema and focal or diffuse hyperemia [8,9].…”

“…Chronic endometritis was identified in 30.3% of patients with repeated implantation failure at ICSI and women diagnosed with it had lower implantation rates (11.5%) after an ICSI cycle [11]. In contrast, Kasius and coworkers [7] reported that the clinical implication of chronic endometritis seems minimal since they diagnosed this condition in 2% of asymptomatic infertile patients with a normal transvaginal ultrasound examination (TVS). The same author reported that the reproductive outcome at ICSI cycles was not negatively affected by chronic endometritis and that the low prevalence and unknown clinical significance of it warrants further study [7,12].…”

Chronic Endometritis: Diagnostic Considerations in Patients With Infertility

“…[5][6][7] Immunohistochemistry is a commonly used ancillary test in pathology, and immunostains such as CD138 and MUM1 have been shown to be helpful to identify endometrial stromal PCs. 23,24 Although multiple sources suggest additional morphologic findings, such as spindling of the stroma and endometrium that is hard to date, as diagnostic features of CE, 2,6,16 the minimal diagnostic criteria for CE are controversial. 3,7,23 A substantial number of articles in the fertility literature use a threshold of 1 or more PCs identified using CD138 IHC as the minimal diagnostic criterion for CE.…”