Performance of GeneXpert ultra in the diagnosis of Tuberculous Cervical lymphadenitis in formalin fixed paraffin embedded tissues

• Published in: Tuberculosis (Edinburgh, Scotland) Vol. 125; p. 102012
• Main Authors: Romdhane, Emna, Arfaoui, Amira, Benabdessalem, Chaouki, Ksentini, Meriam, Ferjani, Asma, Dekhil, Neira, Lahiani, Rim, Bchiri, Soumaya, Mardassi, Helmi, Barbouche, Mohamed-Ridha, Boutiba Ben Boubake, Ilhem, Ben Salah, Mamia, Rammeh, Soumaya
• Format: Journal Article
• Language: English
• Published: Scotland Elsevier Ltd 01.12.2020; Elsevier Science Ltd
• Subjects: Diagnosis; Diagnostic systems; Formaldehyde; Formalin fixed paraffin embedded tissues; Fresh tissues; GeneXpert ultra; Lymphadenitis; Microbiology; Paraffin; Paraffins; Tissues; Tuberculosis; Tuberculous cervical lymphadenitis; Fresh tissues; GeneXpert ultra; Formalin fixed paraffin embedded tissues; Diagnosis; Tuberculous cervical lymphadenitis
• ISSN: 1472-9792; 1873-281X
• DOI: 10.1016/j.tube.2020.102012

The diagnosis of Tuberculous Cervical lymphadenitis (TCL) is challenging. The present study aimed to assess the performance of GeneXpert ultra (GXu) in the diagnosis of TCL on Formalin Fixed, Paraffin Embedded Tissues (FFPET). This study included 35 TCL cases confirmed by positive microbiology and/or positive GXu on Fresh Tissues (FT). The diagnostic performance parameters of GXu on FFPET were determined with reference to microbiology (positive Ziehl Neelsen and/or positive culture) and with reference to positive microbiology and/or positive GXu on FT. The GXu on FFPET was positive in 26/35 (74%) cases. With reference to positive ZN and or culture, the sensitivity, specificity, positive predictive value, and negative predictive value of GXu on FFPET were 63%, 100%, 100% and 71% respectively. With reference to positive microbiology and/or positive GXu on FT, these rates were 74%, 100%, 100% and 40% respectively. GXu on FFPET is a reliable tool for the detection of Mycobacterium tuberculosis complex particularly for cases where microbiological investigations have not been performed. •GeneXpert ultra analyses are routinely performed on Fresh tissues.•Mycobacterium detection by GeneXpert ultra on FFPE lymph nodes is reliable.•GeneXpert ultra on FFPE lymph nodes is an alternative of GeneXpert ultra on Fresh tissue.