All eligible females (aged ≥ 16 yr) between 2012 and 2018, who were newly diagnosed as either FGTB or tuberculous peritonitis (TBP) in the region, were included in the study. In the specific period, 127 consecutive females (aged 18-81 yr) were diagnosed in our center with the disease. Among them, 7 patients unclearly diagnosed after re-evaluation, 9 patients suspected with DR-TB and additional 2 elderly patients with comorbidity of malignancy, were ineligible for receiving standard treatment and excluded. The remaining 109 patients were divided into group A (younger females at reproductive age, aged 18-35 yr) and group B (older females at reproductive age and postmenopausal period, aged 36-81 yr) (Figure 1).
Clinical data collection
Collected clinical data included epidemiological and clinical characteristics, hematological and biochemical tests, and Tuberculin Skin Test (TST) or T-SPOT.TB (T-SPOT.TB replaced TST from 2015). All patients took chest x-ray and 95 underwent chest computerized tomography (CT) scan during hospitalization. Patients with comorbidity of PTB, either active or non-active, were carefully evaluated with imaging data stored in our electronic image system whenever needed. Fourty-two patients underwent laparotomy, laparoscopy or hysteroscopy. Surgical and histological findings were carefully recorded. Ultrasound-guided peritoneocentesis was performed in 59 of 86 patients with performance of ascites. Data of ascitic tests, including routine and biochemical tests, adenosine deaminase (ADA), acid-fast bacilli (AFB) on smear or culture, were also recorded. Positive definition of TST followed National Guidelines of Tuberculosis Diagnosis (WS 288-2017, China). Operative procedures and positive definition of T-SPOT.TB followed instructions of T-SPOT.TB assay kit (Oxford Immunotec, Abingdon, UK). According to relevant reports to T-SPOT.TB [13, 14] and its efficacy for interpreting active TB in the region, a response was considered stronger (moderate-to-strong) positive in this study if the number of spots per test well was ≥16 (when the background control count was < 5), or at least triple the value found in the background control wells (when the background control count was ≥5).
Diagnostic criteria for FGTB and TBP
A “definite” diagnosis of FGTB was considered in the presence of ≥2 of the following: (ⅰ) epidemiological, clinical, and imaging or surgical evidence of FGTB involvement; (ⅱ) positive result of AFB on smear/culture; (ⅲ) stronger positive TST/T-SPOT.TB, (ⅳ) histopathological presence of TB granulomas. Presumptive diagnosis of FGTB was made if there was strong clinical suspicion, such as clinical or explorative features, genital lesions (tubo-ovarain mass) and/or PTB on imaging, and clinically confirmed when the diagnostic ATT proved to be effective.
A “definite” diagnosis of TBP was based on the presence of high-protein (>2.5 g/dL) ascites containing >250 white blood cells/mm3 along with ≥2 of the following: (ⅰ) imaging evidence of peritoneal inflammation; (ⅱ) ascetic ADA levels>35 u/L (ⅲ) stronger positive TST/T-SPOTTB; (ⅳ) positive AFB on smear/culture or presence of TB granulomas in the peritoneal biopsies. Presumptive diagnosis of TBP was smilar to FGTB (except genital lesions).
ATT protocol and management of side effects
Intensive phase included 4 drugs (isoniazid 300 mg, rifampicin 450mg, pyrazinamide 1250 mg, and ethambutol 750mg) daily for 2 months. Patients weighing >50 kg received additional doses of rifampicin, pyrazinamide and ethambutol (150 mg, 250 mg and 250 mg, respectively). The continuation phase included isoniazid and rifampicin for 7-10 months according to individual response (9-12 months’ duration widely taken in EPTB management in the specific period). Drug-induced side effects were all recorded and managed in comprehensive measures relevant to individual performance.
Follow-up and compliance to treatment
Patients were registered and followed up at regular intervals at TB clinics of our center. DOT was administered by patients’ family members (trained by professional physicians) in the region. Whole blood tests, liver function tests, chest x-ray or chest CT, and abdominal ultrasonic scan/ CT were done per month in the intensive phase and every 2-3 months in the duration phase. Patients who reduced doses of drug-intake for side effects received symptomatic treatment after careful counseling. Patients who took irregular protocol (taking drugs < 80% of intended days, or stopped drug-intake under no guidance) or lost to follow-up were defined as poorly compliant patients and excluded on intent-to-treat analysis.
Assessment at two observation time-points
Based on the aim of the study, the efficacy of treatment was assessed in 109 patients at 6 months and 9 months from the initiation of ATT respectively (per-protocol analysis). All patients underwent clinical evaluation and abdominal-pelvic imaging to demonstrate healing of lesions. Chest CT scan and AFB smear/culture of sputum were repeated in those who presented with PTB and regarded as an important measure to demonstrate the response to treatment. Twenty-three patients were persuaded to repeat hysteroscopy and/or endometrial biopsy. Surgical and histopathological findings were recorded for assessment.
“Complete clinical response” was defined as complete resolution of symptoms and signs, normalization of biochemical and hematological tests, and healing of TB lesions on imaging or repeat surgical procedures in this study. A partial response was defined as resolution of clinical manifestations and partial healing of TB lesions. Non-response was defined persistent clinical symptoms, persistence of TB granuloma on histopathology or AFB on microscopy/culture, persistence of TB lesions on imaging or repeat surgical procedures. Healing of PTB referred to healing of active PTB lesions (miliary tubercles, cavity, infiltrated lesions and tuberculous pleural effusion) along with no progression of non-active PTB.
Recurrence during 18-month follow-up
Eighty-eight patients persisted for 9-month treatment. Patients with clinical response were followed up 6-monthly for 18 months at TB clinics of our center, and those with no response every 1-3 months. Those who failed to visit the clinics were contacted telephonically and interviewed for recurrence. To compare the disparity of recurrence rate between 2 groups on intent-to-treat analysis, patients who lost to follow-up were defined as individuals with no recurrence.
Statistic analysis was conducted using SPSS version 22.0 (IBM, Armonk, New York, USA). Parametric results are expressed as mean (range) where appropriate. Non parametric category of variables was analyzed by χ2 test, χ2 with Yate’s correction or Fisher’s Exact test, where applicable. Two-sided P < 0.05 was considered as statistically significant.