Nontuberculous mycobacterial and Aspergillus infections among cadaveric lung transplant recipients in Japan

Lymphangioleiomyomatosis Showing the Development of Mycobacterium abscessus subsp. massiliense Infection during Sirolimus Therapy

Among nontuberculous mycobacterial pulmonary diseases (NTM-PDs), Mycobacterium abscessus species pulmonary disease (MABS-PD) is one of the most severe and intractable infections. We herein report a 45-year-old woman with advanced lymphangioleiomyomatosis (LAM) who developed MABS-PD while undergoing sirolimus therapy. MABS-PD was immediately controlled using antibiotic therapy, although the patient's lung transplant registration was significantly delayed. To our knowledge, this is the first case report on the development of NTM-PD in a patient with LAM before lung transplantation. This case suggests that the early diagnosis and optimal treatment of NTM-PD are crucial in patients with advanced LAM.

Nontuberculous Mycobacterial Pulmonary Infection Among Lung Transplant Recipients

OBJECTIVES

Data are limited regarding the clinical significance of nontuberculous mycobacteria pulmonary infections among lung transplant recipients. We investigated the incidence and characteristics of pulmonary nontuberculous mycobacteria infection in ourlung transplant patient population.

MATERIALS AND METHODS

We obtaineddata of the patients who underwent lung transplant in our center from January 1997 to March 2019.

RESULTS

Of 690 patients, nontuberculous mycobacteria were identified in 58 patients (8.4%) over a median follow-up of 3 years. Types of species were as follows: Mycobacterium simiae (n = 24), avium complex (n = 12), abscessus (n = 9), fortuitum (n = 6), chelonae (n = 2), szulgai (n = 1), kansasii (n = 1), lentiflavum (n = 1), and undefined mycobacteria (n = 2). When we compared infections in the early versus late period posttransplant (before and after 6 months), infections with Mycobacterium simiae (16 vs 8 incidents) and Mycobacterium fortuitum (5 vs 1 incident) were more often observed within the early period, whereas most Mycobacterium abscessus (7 vs 1 incident) and Mycobacterium avium complex (9 vs 3 incidents) were observed in the later period. The median forced expiratory volume in 1 second overtime did not differ significantly between patients with and without nontuberculous mycobacteria infection (P = .29). Nontuberculous mycobacteria acquisition was significantly associated with decreased survival (relative risk of 2.41, 95% CI, 1.70-3.43; P ⟨ .001).

CONCLUSIONS

The nontuberculous mycobacteria species isolated varied according to the time elapsed since transplant. Among lung transplant recipients, nontuberculous mycobacteria infection was associated with increased mortality but not with lung dysfunction.

Nontuberculous mycobacterial infection after lung transplantation: A single-center experience in South Korea

PURPOSE

Nontuberculous mycobacteria (NTM) infection is an important issue after lung transplantation. However, a large-scale epidemiological study on this issue in Korea is lacking. We aimed to evaluate the epidemiology of NTM infection after lung transplant surgery in Korea.

METHODS

Between October 2012 and December 2018, we retrospectively evaluated lung transplant recipients in a referral hospital in South Korea. A total of 215 recipients were enrolled. The median age at transplantation was 56 years (range, 17-75), and 62% were men. Bronchoscopy was performed according to the surveillance protocol and clinical indications. A diagnosis of NTM infection was defined as a positive NTM culture from a bronchial washing, bronchoalveolar lavage sample, or two separate sputum samples. We determined NTM pulmonary disease (NTM-PD) according to the American Thoracic Society/Infectious Disease Society of America 2007 guidelines. The Kaplan-Meier method and log-rank test were used for conditional survival analysis in patients with follow-up of ≥12 months.

RESULTS

Fourteen patients (6.5%) were diagnosed with NTM infection at a median of 11.8 months (range, 0.3-51.4) after transplantation. Nine patients (4.2%) were diagnosed with NTM-PD, and the incidence rate was 1980/100,000 person-years. Mycobacterium abscessus was the most common species causing NTM-PD (66%), followed by M. avium complex (33%). The presence of NTM infection did not influence all-cause mortality among those who underwent follow-up for ≥12 months (N = 133, log-rank P = 0.816).

CONCLUSION

The incidence of NTM-PD was considerably high among lung-transplant recipients. M. abscessus was the most common causative species of NTM-PD after lung transplantation.

Challenges in the Diagnosis and Management of Bacterial Lung Infections in Solid Organ Recipients: A Narrative Review

Respiratory infections pose a significant threat to the success of solid organ transplantation, and the diagnosis and management of these infections are challenging. The current narrative review addressed some of these challenges, based on evidence from the literature published in the last 20 years. Specifically, we focused our attention on (i) the obstacles to an etiologic diagnosis of respiratory infections among solid organ transplant recipients, (ii) the management of bacterial respiratory infections in an era characterized by increased antimicrobial resistance, and (iii) the development of antimicrobial stewardship programs dedicated to solid organ transplant recipients.

Nontuberculous mycobacterial infection after lung transplantation: a report of four cases

Background

Nontuberculous mycobacterium (NTM) infection in a patient in an immunosuppressed state caused by increased use of immunosuppressive or biological agents is a serious clinical problem. Mycobacterium avium complex is the most common involved pathogen, followed by Mycobacterium abscessus (MABSC), while Mycobacterium kansasii is not a major concern. The rate of infection rate in lung transplant recipients is reported to range from 1.5–22.4%.

Case presentation

We report here four cases of NTM pulmonary infection and disease among 63 patients who underwent lung or heart-lung transplantation at our hospital. Those four occurred following living-donor transplantation in two patients, one with pulmonary arterial hypertension and one with bronchiectasia, and deceased donor lung transplantation in two patients, lymphangioleiomyomatosis and interstitial pneumonia, respectively. NTM was not detected in any of the patients prior to transplantation. The involved pathogens were Mycobacterium gordonae in one, MAC in one, and MABSC in two of these patients, which were isolated from broncho-alveolar lavage (BAL) in two and sputum in two. The one case of MAC and two of MABSC were symptomatic with consolidation shown in chest CT images indicating possible pneumonia, while the one with M. gordonae had no symptoms and was detected by surveillance BAL. Onset time from detection of NTM was greater than 3 years in the three with MABSC and M. gordonae and less than 3 years in the one with MAC. Each patient required a decrease in immunosuppressive agents according to their condition, while antibiotics therapy was performed in the three who were symptomatic. Sputum culture findings became negative after several months and were maintained thereafter in all.

Conclusion

An NTM infection leading to pulmonary disease can occur at any time following lung transplantation. Treatment should be considered depending on the involved pathogens, individual status, and disease severity.