Reappraisal of the Role of Ascitic Fluid Adenosine Deaminase for the Diagnosis of Peritoneal Tuberculosis in Cirrhosis

Abstract

Background/Aims: Although peritoneal tuberculosis (TB) is one of the important differential diagnoses among cirrhotic patients with ascites, a peritoneal biopsy is not always available. High ascitic fluid adenosine deaminase (ADA) has been indicative of peritoneal TB. On the other hand, studies to assess its diagnostic utility based on the confirmation of peritoneal biopsy in cirrhotic patients are scarce. Methods: Patients with new-onset ascites were enrolled prospectively from a tertiary hospital. Peritoneal biopsy was applied according to clinical judgment when required. Based on pathology diagnosis of the peritoneum, the diagnostic efficacy of ascitic fluid ADA for peritoneal TB was evaluated in total and cirrhotic patients, respectively. Results: Among 286 patients enrolled, 78 were diagnosed with peritoneal TB. One hundred and thirty-two patients had cirrhosis, and 30 of those were diagnosed with peritoneal TB. The mean ADA was 72.2 U/L and 22.7 U/L in the peritoneal and non-peritoneal TB group, respectively, among the total study population, and 64.0 U/L and 19.1 U/L in the peritoneal and non-peritoneal TB group, respectively, among the subgroup with cirrhosis. The area under the curve for ADA to diagnose peritoneal TB was 0.96 in the total study population with a cutoff value of 41.1 U/L, and 0.93 in cirrhotic patients with a cutoff value of 39.9 U/L. Conclusions: The ascitic fluid ADA measurements showed high diagnostic performance for peritoneal tuberculosis in patients with ascites regardless of cirrhosis at a similar cutoff value.

Diagnostic performance of adenosine deaminase for abdominal tuberculosis: A systematic review and meta-analysis

“…In one of the studies included, Dahale et al investigated the diagnostic value of ADA for peritoneal TB in cirrhosis. The ADA cut-off value of peritoneal TB in the cirrhosis subgroup (64.0 IU/L) was slightly lower than that of the peritoneal TB group (72.2 IU/L), which might be related to the interference of bilirubin changes in cirrhosis on ADA value ( 42 ). Fourth, HIV-induced immunodeficiency increases the likelihood of Mtb infection, and patients living with HIV have lower ADA levels than their seronegative counterparts ( 76 ).…”

“…); and 4 studies included animal experiments (rats, mice, etc.). The full text of remaining articles was reviewed; 24 of the 76 articles were included in the meta-analysis ( 29 – 33 , 42 – 60 ) ( Figure 1 ).…”

“…The main characteristics of 24 studies were listed in Tables 1 , 2 ( 29 – 33 , 42 – 60 ). Data were collected from 11 countries (five low-burden and six high-burden) between 1989 and 2021.…”

“…To avoid bias and ambiguity, the methodological quality of the included studies was evaluated by the four aspects through QUADAS-2 ( Figures 2A,B ). In patient selection bias, two high-risk articles came from a case-control study ( 30 , 42 ) and one unclear article lacked an inclusion period ( 59 ). In the index test bias, three unclear articles did not report the blinding method ( 29 , 49 , 53 ).…”

“…The same three unclear articles also did not report the reference standard blinding method ( 29 , 49 , 53 ). Regarding flow and timing bias, seven unclear articles showed that participants accepted different reference standards ( 30 , 42 , 43 , 49 , 55 , 57 , 60 ). Generally, the overall quality of the included articles was good.…”