Clinical Presentation, Diagnosis, and Bacterial Epidemiology of Peritoneal Tuberculosis in Two University Hospitals in France

Thirty-four patients were included (29 in Lyon and 5 in Nancy). There was male predominance, with 22 men and 12 women; median age was 40 years. Twenty-six patients (76.5%) were migrants from areas of endemic TB, mainly Africa. One or more underlying disease was found in 13 patients (38.2%): liver cirrhosis (6), diabetes mellitus (6), chronic viral hepatitis (4) or immunodepression as cancer (4), immunosuppressive therapy (3) and human immunodeficiency virus (1, who was already treated and controlled). HIV was tested for 32/34 patients (94.1%). Two patients (5.9%) had history of cured TB; history of TB exposure was reported by seven patients (20.6%). The main presentation that lead to hospitalization (29 patients: 85.3%) was a checkup of ascites or suspicion of peritoneal carcinomatosis; two patients (5.9%) presented peritonitis. The main symptoms and signs are given in Table 1. Four patients (11.8%) presented acute abdominal illness requiring emergency laparotomy (two initially and two secondarily). Median symptom duration before admission was 1 month.

Biological findings revealed biological inflammatory syndrome in all patients, with a median C-reactive protein level of 95 mg/L. Lymphopenia (under 1.5 G/L) was found in 23 of the 30 patients investigated (76.7%). Interferon-γ release assay (QuantiFERON-TB^®; Cellestis) was positive in only 16/22 patients (72.7%), and 15/24 (62.5%) had positive (at least 10 mm) tuberculin test (Tubertest^®; Sanofi Pasteur). Ascitic fluid analysis found exudate in 17/21 patients (80.1%), with lymphocytic predominance in 19/21 cases (90.5%).

On abdominal computed tomography (CT), ascites was found in 29/32 patients (90.6%), and was the only abnormality in 4/32 of these (13.8%). Peritoneal, mesenteric, and/or omentum thickening (Fig. 1) was detected in 24 patients (75%). Only three patients (8.9%) had no ascites on CT scan, corresponding to the “dry plastic” form of pTB, defined by Bhargava [8]. Abdominal ultrasound was equal to CT to detect ascites (25/28, 89.3%) but less efficient in detecting peritoneal thickening (6/28, 21.4%). Six patients (17.8%) had positron emission tomography, showing increased peritoneal or mesenteric and lymph node metabolic activity, which could not be differentiated from carcinomatosis. Thirty-two out of 34 thoracic CT (94.1%) were abnormal with pleural effusion (12), mediastinal lymph node (9), micronodules (8), nodule (4), or excavation (1). Surgery was required for diagnosis in 20 cases (58.8%), including 14 laparoscopies (41.2%) and six laparotomies (17.6%). Intraoperative visual inspection was suggestive of pTB in 13 patients (65%), with typical small white peritoneal granulations or granuloma. Six of the patients who did not undergo surgery (42.9%) had ultrasound-guided peritoneal biopsy. Tuberculous peritonitis was culture-confirmed in 25 patients. Diagnostic performance of the various bacteriological and histological analyses is shown in Table 2. TB PCR, performed on 13/31 ascites samples and on 8/14 peritoneal biopsies, was systematically negative on ascites and positive on only 2 peritoneal biopsies (25%). It should be noted that a large number of peritoneal biopsies were not sent to the bacteriology laboratory (8/22, 36.4%), because only malignant ascites was suspected by the surgeon. Finally, histological and/or bacteriological diagnostic proof was obtained in all patients, except for three (8.8%) who did not have peritoneal biopsy but were cured by the anti-TB treatment.

Twenty-six infections were documented. Mycobacterium bovis was isolated in 6 patients (23.1%) and M. tuberculosis in the others 20 (76.9%). All isolates were susceptible to classical anti-mycobacterial drugs, except one case of isoniazid resistance (M. bovis is naturally resistant to pyrazinamide). Genetic analysis by spoligotyping, performed in 21 cases, revealed that 8 (38%) belonged to lineage T (Table 3). T family lineage is characterized by the absence of spacers 33–36 among the 43 spacers targeted by spoligotyping; the prototypic shared spoligotype is SIT53. There was no specific clinical characteristic for the spoligotype T.

Sixteen patients (47.1%) showed one or more other TB location, including lung (five patients), and digestive (four patients), gynecological (four patients) and urological (two patients) tract. Sputum smear examination or bronchoalveolar lavage was performed in 32 patients (94.1%) and cultures were positive for 5 patients (14.7%). Extensive surgery with intestinal resection was required in two patients because of digestive perforation; corticosteroids were prescribed for subocclusive syndrome in two patients; and three malnourished patients required artificial nutrition. Median admission-to-treatment time was 18 days. Antimycobacterial therapy comprised standard regimen with daily rifampicin, isoniazid, ethambutol and pyrazinamide during 2 months followed by at least 4 months of rifampicin and isoniazid for 24 patients (70.6%); the others had therapy without pyrazinamide or without isoniazid and/or with quinolone because of toxicity or hepatic disorder before treatment. Side-effects led to dose decrease or a change of treatment in 13 patients (38.2%). Twenty-six patients (76.5%) completed treatment and were clinically and radiologically cured; four were lost to follow-up; one was still under treatment at the time of writing; and three died during treatment (only one because of disseminated TB). Median treatment duration was 8.5 months, and follow-up without relapse after end of treatment was 12 months.