SUCCESSFUL TREATMENT WITH CLOFAZIMINE FOR MACROLIDE-RESISTANT MYCOBACTERIUM ABSCESSUS INFECTION IN A PERITONEAL DIALYSIS PATIENT

【Introduction】　Nontuberculous mycobacteria (NTM) are rare but serious pathogens in peritoneal dialysis (PD)-associated infections, leading to PD discontinuation in 92.9% of the affected patients. Mycobacterium abscessus (M. abscessus), which accounts for 8.8% of NTM PD-associated infections, is usually resistant to standard anti-tuberculosis drugs, and no established antimicrobial treatment strategy or duration has not been established for M. abscessus PD-associated infections. Furthermore, since macrolide antibiotics are key drugs for treating M. abscessus due to their antimicrobial and immunomodulatory effects, macrolide-resistant strains pose particular challenges, especially for prolonged treatment requiring oral agents. We report the first case of macrolide-resistant M. abscessus PD catheter tunnel infection successfully treated with multimodal therapy including clofazimine-containing combination therapy. 

【Case presentation】　A 63-year-old man with end-stage kidney disease secondary to autosomal dominant polycystic kidney disease, who had been on PD for one year, presented with persistent purulent discharge from his PD catheter exit site. Physical examination revealed localized erythema and purulent discharge without fever or systemic symptoms. Laboratory findings showed mild elevation in C-reactive protein (0.17 mg/dL), while peritoneal dialysis effluent remained clear with normal white blood cell count, excluding peritonitis. Skin swab culture identified macrolide-resistant M. abscessus, confirming the diagnosis of M. abscessus PD catheter tunnel infection after ruling out extension to deeper structures. The patient transitioned to hemodialysis following catheter removal 11 days after symptom onset, with extensive surgical debridement and a 6-week combination antibiotic therapy including imipenem-cilastatin, amikacin and clarithromycin, achieving clinical cure. However, the infection recurred after 5 months, necessitating retreatment with debridement and an antibiotic regimen including imipenem-cilastatin, amikacin, azithromycin and clofazimine for 4 weeks, followed by a continuation regimen with amikacin, clofazimine and sitafloxacin for 4 months. This approach achieved sustained clinical cure without recurrence at 14 months follow-up. 

【Conclusion】　Narrative literature review of 67 reported cases of M. abscessus PD-associated infections revealed that 6 cases with macrolide-sensitive strains were treated with clofazimine, all of which achieved clinical cure. However, there is no case report on macrolide-resistant M. abscessus PD-associated infections treated with clofazimine. Our case represents the first successful treatment of macrolide-resistant M. abscessus PD-associated infection using clofazimine-containing combination therapy, demonstrating clofazimine as a potential therapeutic option in combination therapy. Multimodal therapy including early catheter removal, extensive surgical debridement, and prolonged multidrug antimicrobial regimens containing clofazimine may represent a viable treatment strategy for sustained cure in this challenging clinical context.

This case was presented at the 70th Annual Meeting of the Japanese Society for Dialysis Therapy.