Israel Medical Association Journal

Background: The incidence of non-tuberculous mycobacterium (NTM) infections has been rising in patients with chronic lung diseases. These infections cause significant morbidity, mortality, and elevated healthcare costs due to challenges in recognition, delayed diagnosis, and treatment. While NTM infections in natural stone silicosis are documented, the incidence in artificial stone silicosis remains unexplored despite increasing exposure to silica dust.

Objectives: To describe the clinical, radiological, and pathological features of NTM infections in patients with artificial stone silicosis and emphasize the importance of early diagnosis.

Methods: We reviewed the database of a tertiary medical center in Israel from 2010 to 2024 and identified patients with occupational artificial stone silicosis diagnosed with NTM infection.

Results: We found eight patients with occupational artificial stone silicosis, all male, aged 42–74 years. Key symptoms included dyspnea, cough, weight loss, and fever. Computed tomography revealed mediastinal lymphadenopathy, progressive massive fibrosis, calcifications, pulmonary cavitations, pleural thickening, traction bronchiectasis, pulmonary nodules, and honeycombing. Biopsies showed silicotic nodules, birefringent crystals, pulmonary alveolar silico-proteinosis, fibrosis, and honeycombing. Four patients received NTM-targeted antibiotics, and six underwent lung transplantation. Four patients died.

Conclusions: Artificial stone silicosis may be associated with NTM infections. Early diagnosis requires a high degree of clinical suspicion. New or worsening respiratory or systemic symptoms in patients with silicosis should prompt further microbiological evaluation, including sputum culture or bronchoalveolar lavage. Further studies are needed to assess the incidence of NTM infections in this population.

Crohn's disease patients undergoing anti-tumor necrosis factor (anti-TNF) therapy such as infliximab face potential risks from opportunistic infections. We introduce the unique case of a 66-year-old male Crohn's patient, previously in remission, presenting with gastrointestinal symptoms following a trip to the Czechia. Despite concerns of reactivated tuberculosis due to infliximab, his biopsies showed the presence of Mycobacterium simiae (M. simiae). Despite this, anti-TNF therapy was continued and resulted in clinical improvement. This is a case report of M. simiae in intestinal biopsies of an immunocompromised Crohn's patient is a clinical challenge. The findings suggest the benign colonization of M. simiae potentially influences future treatment considerations in similar clinical scenarios.

Background: Patients with end-stage renal disease are at high risk of mycobacterial infection.

Objectives: To analyze the difficulties in reaching an accurate diagnosis of tuberculosis in dialysis patients.

Methods: We conducted a retrospective follow-up of patients who attended our peritoneal and hemodialysis units during the 10 year period 1995–2005.

Results: Our dialysis unit diagnosed 10 cases of tuberculosis caused by Mycobacterium tuberculosis and 9 cases of Mycobacterium other than tuberculosis. In the former group, five patients had mycobacterium in the sputum, which was diagnosed by intraabdominal mass biopsy in one, culture of the gastric juices in one, and pleural fluid culture or pleural biopsy in three. One of these patients was suffering from pleural TB[1] as well as Potts disease. Of the patients with Mycobacterium other than tuberculosis, five were diagnosed by sputum cultures, three by urine cultures and one in peritoneal fluid. Differences in treatment and outcome were also reviewed.

Conclusions: The diagnosis of TB in dialysis patients should be approached with a high index of suspicion. It is clear that extensive diagnostic procedures are required to ensure an accurate diagnosis of the disease. Tuberculosis incurs a significant added burden due to the need for isolation of infected patients within the dialysis unit. Treatment of patients with Mycobacterium other than tuberculosis should be addressed individually.