Nontuberculous Mycobacterial Infection Mimicking Lung Cancer in A Patient with Usual Interstitial Pneumonia Pattern Interstitial Lung Disease: A Case Report

BACKGROUND

It has been reported that structure damage in the parenchymal lung disease such as idiopathic pulmonary fibrosis (IPF) is associated with high susceptibility to nontuberculous mycobacterial (NTM) infection. Radiologic features of NTM lung disease in destructive lung parenchyma can be atypical, which can cause confusion with other diseases including malignancy. Prompt and accurate identification of newly developed lesions in the follow-up computed tomography (CT) of IPF patients is challenging but crucial.

CASE REPORT

We reported a case of an NTM infection in a patient with IPF, manifested as a mass-like consolidation with cavitation on chest CT, mimicking lung cancer.

CONCLUSION

Being aware of the unusual radiologic features of NTM lung disease in IPF patients can be useful in the differential diagnosis of newly detected lesions.

A case of mediastinal abscess and infected aortic aneurysm caused by dissemination of Mycobacterium abscessus subsp. massiliense pulmonary disease

An 81-year-old man was admitted to our hospital because of fever and malaise that had persisted for 3 months. The patient had undergone two aortic valve replacements, 10 and 5 years previously, because of aortic valve regurgitation and infectious endocarditis. He also had had asymptomatic Mycobacterium abscessus complex (MABC) pulmonary disease for the two previous years. Contrast-enhanced computed tomography showed a mediastinal abscess and an ascending aortic aneurysm. Mycobacterium abscessus subsp. massiliense was cultured from his blood, suggesting the aortic aneurysm was secondary to infection of an implanted device. After enlargement over only a few days, a leakage of contrast medium to the mediastinal abscess was found on computed tomography. The patient was diagnosed with rupture of an infectious aortic aneurysm, and emergency aortic replacement and drainage of the mediastinal abscess were successful. The patient was treated with several antibiotics, including meropenem, amikacin, and clarithromycin, and his general condition improved. Cultures from both the mediastinal abscess and a pericardial patch that was placed at the time of surgery 5 years previously revealed MABC. In our case, the infected aortic aneurysm most likely resulted from MABC pulmonary disease rather than from previous intraoperative contamination. This route of infection is rare. Physicians should be aware of the possibility of dissemination and subsequent infection of implants related to MABC pulmonary disease.

Immunotactoid Glomerulopathy with Nontuberculous Mycobacterial Infection: A Novel Association

A 70-year-old woman underwent a renal biopsy due to nephrotic syndrome. She had suffered from nontuberculous mycobacterial infection (NTM) for 14 years. The patient was diagnosed as having membranoproliferative glomerulonephritis (MPGN) type 3 and immunoglobulin (Ig)-associated MPGN based upon LM/erythromycin and IF findings, respectively. In high-magnification imaging, electron-dense deposits showed immunotactoid glomerulopathy (ITG). There was no evidence of hematological cancer, and the patient improved after receiving treatments for NTM. To the best of our knowledge, this patient is the first to show an association between ITG and NTM. Although ITG is generally considered as related to lymphoproliferative disease, it is suggested that ITG is driven by bacterial infection and is a potential outcome of Ig-associated MPGN.

Incidence of ocular inflammation among patients with active tuberculosis or nontuberculous mycobacterial infections in a tertiary hospital in Japan

PURPOSE

This study aimed to elucidate the incidence of ocular involvement among patients with active tuberculosis (TB) or nontuberculous mycobacterial (NTM) infection in a hospital in Japan.

METHODS

Patients with active TB or NTM infection at Yoshijima Hospital from April 2017 to July 2018 were included in this retrospective study. All patients underwent ophthalmic examinations, including fundus evaluation under pupil dilation, before initiation of antibiotic therapy. Patients with ocular inflammation were regularly followed up by ophthalmologists.

RESULTS

In total, 101 patients with active TB and 27 patients with active NTM infection underwent ophthalmic examinations during the study period. Seven patients with TB (6.9%) had ocular inflammation; four had bilateral involvement. In these seven patients, ocular inflammation comprised anterior uveitis (n = 2), intermediate uveitis (n = 1), posterior uveitis (n = 4). Choroidal tubercles were observed in two patients with posterior uveitis. Female sex was associated with higher incidence of ocular inflammation among patients with TB. Conversely, no patients with NTM infection had ocular inflammation.

CONCLUSION

Ocular inflammation was present in approximately 7% of patients with active TB. Although TB choroiditis is presumed to be rare in Japan, approximately 30% of the patients with ocular inflammation exhibited choroidal lesions in this study. In contrast, no ocular inflammation was observed among patients with systemic NTM infection.

Disseminated Mycobacterium abscessus subsp. massiliense infection in a Good's syndrome patient negative for human immunodeficiency virus and anti-interferon-γ autoantibody: a case report

Background

Good’s syndrome (GS) is characterized by immunodeficiency, and can lead to severe infection, which is the most significant complication. Although Mycobacterium rarely causes infection in patients with GS, disseminated nontuberculous mycobacterial (NTM) infection frequently occurs in GS patients that are also positive for the human immunodeficiency virus (HIV) or anti-interferon (IFN)-γ autoantibodies. Here, we report a rare case of GS with NTM without HIV or IFN-γ autoantibodies.

Case presentation

A 57-year-old Japanese male with GS and myasthenia gravis (treated with prednisolone and tacrolimus) was diagnosed with disseminated NTM infection caused by Mycobacterium abscessus subsp. massiliense. He presented with fever and back pain. Blood, lumbar tissue, urine, stool, and sputum cultures tested positive for M. abscessus. Bacteremia, spondylitis, intestinal lumber abscess, and lung infection were confirmed by bacteriological examination and diagnostic imaging; urinary and intestinal tract infections were suspected by bacteriological examination but not confirmed by imaging. Despite multidrug combination therapy, including azithromycin, imipenem/cilastatin, levofloxacin, minocycline, linezolid, and sitafloxacin, the patient ultimately died of the infection. The patient tested negative for HIV and anti-IFN-γ autoantibodies.

Conclusions

Since myasthenia gravis symptoms interfere with therapy, patients with GS and their physicians should carefully consider the antibacterial treatment options against disseminated NTM.

CapitalBio Mycobacterium real-time polymerase chain reaction detection test: Rapid diagnosis of Mycobacterium tuberculosis and nontuberculous mycobacterial infection

OBJECTIVES

To evaluate the accuracy of the CapitalBio Mycobacterium real-time polymerase chain reaction (RT-PCR) detection test for pulmonary Mycobacterium tuberculosis (MTB) and nontuberculous mycobacterial (NTM) infection.

METHODS

This study analyzed 2,460 samples from patients with suspected pulmonary mycobacterial infection collected between 01 June 2018 and 31 July 2019. It aimed to determine the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the curve (AUC) of the CapitalBio Mycobacterium detection test for MTB and NTM infections, and to evaluate its diagnostic accuracy compared with mycobacterial culture.

RESULTS

The sensitivity, specificity, PPV, NPV, and AUC of the CapitalBio Mycobacterium detection test for MTB was 83.0%, 79.9%, 80.8%, 82.2%, and 0.81, respectively. This was similar to the diagnostic accuracy of Xpert MTB/RIF for MTB and was significantly higher than that of smear. For pulmonary NTM infection, the sensitivity, specificity, PPV, NPV, and AUC of the test was 82.0%, 99.6%, 94.1%, 98.5%, and 0.91, respectively. The diagnostic accuracy of the CapitalBio Mycobacterium detection test was also significantly higher than that of smear for NTM.

CONCLUSIONS

The CapitalBio Mycobacterium detection test had good diagnostic accuracy for MTB and NTM infections. This is of great significance for the differential diagnosis of early pulmonary mycobacterial infection.

Pulmonary resection for nontuberculous mycobacterial pulmonary disease: outcomes and risk factors for recurrence

OBJECTIVES

As the number of patients with nontuberculous mycobacterial pulmonary disease (NTMPD) increases, surgical treatment to control disease becomes more important. However, postoperative outcomes and predictors of recurrence have been insufficiently evaluated.

METHODS

We retrospectively investigated 100 patients with NTMPD who underwent pulmonary resection from 2009 to 2016 at our institution. Clinical data of patients with and without postoperative recurrence were statistically compared. Recurrence was defined as microbiological re-identification or computed tomography findings highly suspicious for relapse after excluding other diseases. Recurrence-free survival was calculated using the Kaplan-Meier method. Survival curves were compared using the log-rank test. Predictive factors were evaluated using univariate and multivariate analyses.

RESULTS

Nine patients experienced recurrence. A significant difference in recurrence-free survival was detected between patients with and without a positive preoperative sputum culture (P = 0.000942). Moreover, patients with a positive preoperative sputum smear (≥ 2 +) had a significantly higher recurrence rate than those who did not (P = 0.000216). Multivariate analysis revealed that preoperative sputum smear (≥ 2 +) is an independent risk factor for recurrence after pulmonary resection for NTMPD (odds ratio, 7.38; 95% confidential interval, 1.29-42.2; P = 0.024).

CONCLUSIONS

NTM discharge might have an impact on postoperative recurrence of NTMPD patients without residual cavitary lesions. Preoperative NTM discharge should be minimized by optimizing medical therapy before surgical treatment to improve the postoperative course. Intensive follow-up and prolonged postoperative medical therapy should be considered for patients without a sufficient reduction in bacterial discharge before pulmonary resection.

Successful treatment with mepolizumab in a case of allergic bronchopulmonary aspergillosis complicated with nontuberculous mycobacterial infection

Allergic bronchopulmonary aspergillosis (ABPA) is a complex hypersensitivity reaction that is associated with an allergic immunological response to Aspergillus species via Th2-related inflammation. The long-term use of a systemic corticosteroid is often needed for the treatment of ABPA. However, systemic corticosteroid treatment imposes a risk of the onset of a nontuberculous mycobacterial infection. Here we report the case of a patient with ABPA who required the long-term use of an oral corticosteroid because her repeated asthmatic attacks were successfully treated with mepolizumab, an anti-interleukin-5 monoclonal antibody. The patient, a 60-year-old Japanese female, had been treated with an oral corticoid and itraconazole. Despite the success of the initial treatment for ABPA, it was difficult to discontinue the use of the oral corticosteroid. In addition, Mycobacterium avium was detected from her bronchial lavage. We initiated mepolizumab treatment to taper the amount of corticosteroid and control the asthma condition. The patient's number of blood eosinophils, serum IgE level, fractional exhaled nitric oxide level, dosage of oral prednisolone, and need for inhaled budesonide/formoterol all improved, without an exacerbation of her asthma attacks. Although further research regarding mepolizumab treatment is needed, we believe that mepolizumab could be considered one of the agents for treating refractory ABPA.

Progressive disseminated histoplasmosis with concomitant disseminated nontuberculous mycobacterial infection in a patient with AIDS from a nonendemic region (California)

Background

Opportunistic infections, while well studied in the AIDS population, continue to have variable and surprising presentations. Here, we present a case of disseminated histoplasmosis with disseminated nontuberculous mycobacterial infection in a 50 year old man with long standing AIDS living in a non-endemic area.

Case presentation

Patient presented with a constellation of symptoms, and imaging of the chest showed a pulmonary mass with cavitation, multiple nodules, and ground glass opacities. Further investigations revealed granulomatous lung nodules and fungemia consistent with Histoplasma capsulatum, and coinfection with disseminated nontuberculous mycobateria in a nonendemic area.

Conclusions

Immunocompromised patients risk co-inhabitation by multiple infectious organisms. Some of these organisms may preside in the host for years prior to reactivation. Clinicians in non endemic areas should therefore be careful to not overlook specific organisms based on a lack of a recent travel history. Physicians in nonendemic areas should become more familiar with the clinical findings and diagnostic approach of infectious such as Histoplasmosis, to ensure earlier recognition and treatment in immunocompromised individuals.

Nontuberculous mycobacterial infections of the lower extremities: A 15-year experience

Objectives

Nontuberculous mycobacterial infection (NTMI), which is increasing in prevalence, is challenging to diagnose and manage despite the availability of capable laboratories because of subtle and nonspecific clinical findings and nonstandardized treatment guidelines. We aimed to present our experience with lower-extremity NTMI and to compare clinical characteristics and treatment outcomes between immunocompetent and immunocompromised patients.

Methods

To determine clinical presentations and outcomes, we reviewed electronic health records of all patients with lower-extremity NTMI treated and followed up at our institution from January 2002 through December 2017.

Results

Twenty-four patients were included in this study. Mean (SD) age was 58 (19) years. Eighteen patients (75%) were men; 13 (54%) were immunocompetent; and 9 (37%) had bone and joint involvement. No significant differences existed between immunocompetent and immunocompromised patients, except immunocompetent patients had significantly more infections at the hip, thigh, and toe. Bone and joint infection required significantly longer treatment time than skin and soft-tissue infection.

Conclusions

Regardless of immune status, patients with lower-extremity NTMI had similar characteristics, treatments, and outcomes. However, immunosuppression can be a major risk factor in the development of disseminated NTMI and associated complications. Acid-fast bacilli culture is strongly recommended for evaluation of delayed or nonhealing lesions. Aggressive medical and surgical management can be associated with good clinical outcomes.

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

BACKGROUND

Lung transplantation is an effective treatment modality for respiratory failure. Chronic lung infections, including infections caused by nontuberculous mycobacteria (NTM) and Aspergillus, are difficult to control, and uncontrolled infections are relative contraindications for lung transplantation. However, few reports have documented the incidence and outcome of these infections in lung transplant recipients.

METHODS

To quantify the incidence and outcomes of colonization and disease caused by NTM and aspergillosis in recipients before and after lung transplantation, we reviewed the medical records and microbiology data from 240 consecutive cadaveric lung transplant recipients between 2000 and 2014.

RESULTS

Before lung transplantation, NTM and Aspergillus species were isolated from five (2.1%) and six (2.5%) patients, respectively, out of the total 240 recipients. All patients with NTM infection received treatment, resulting in culture conversion. They had no recurrence after lung transplantation. All patients with aspergillosis received treatment, one of whom had recurrence after lung transplantation. Over a median follow-up period of 3.3 years, NTM species were isolated after transplantation from eight of 240 patients (3.3%). Five of these patients met the criteria for NTM disease, and four of them received treatment. Four patients survived without a worsening of NTM disease. Over the same median follow-up period, Aspergillus species were isolated from seven of 240 patients (2.9%), six of whom received treatment.

CONCLUSIONS

Isolation of NTM or Aspergillus species from lung transplant recipients is uncommon. Adequate pre-transplant control and post-transplant management of NTM and Aspergillus infections allows for safe lung transplantation.

The frequency and treatment of pneumothorax associated with pulmonary nontuberculous mycobacterial infection

OBJECTIVES

Characteristics of pneumothorax associated with nontuberculous mycobacterium (NTM) infection are rarely reported, especially in terms of surgical treatments. Our objectives were to show the tendency and clinical courses of pneumothorax due to NTM and discuss the way of therapy in our hospital.

METHODS

We retrospectively analyzed 557 patients with NTM infection over a period of 5 years at the Nagara Medical Center.

RESULTS

A total of 12 out of the 557 patients (2.2%) suffered from pneumothorax caused by NTM infection without other pulmonary diseases. The diagnosis of all NTM cases was mycobacterium avium complex. Of these 12 patients, three required observation only (25%), five required drainage only (42%), and four required surgery after drainage (33%). The four surgically treated patients suffered from empyema as well as pneumothorax. They were in worse nutritional condition than non-surgically treated patients. For the patients requiring surgery, we selected reasonable surgical methods; we sutured the fistula of lung in all cases and covered it with muscle or omentum or polyglycolic acid sheets without a case in which endobronchial embolization was performed in advance before surgery. Finally, all pneumothorax healed. Thereafter, three of these four patients took unfavorable courses: progressing malnutrition, complications worsening or contralateral pneumothorax.

CONCLUSION

We should select an appropriate treatment including surgery against NTM-associated pneumothorax without losing an opportunity because of its intractability and exhausting effect.

A case of membranoproliferative glomerulonephritis and AA amyloidosis complicated with pulmonary nontuberculous mycobacterial infection

A 75-year-old man was diagnosed with pulmonary nontuberculous mycobacterial (NTM) infection in February 2005 and was treated with rifampicin, ethambutol, and clarithromycin. However, the infection was resistant to treatment, and his chest radiograph showed an abnormality that gradually seemed to aggravate. The patient's sputum was positive for Mycobacteria. Moreover, the patient had dyspnea and an underlying chronic inflammation in the lungs. He visited our hospital because of dyspnea and leg edema in June 2011. Laboratory evaluation on admission revealed proteinuria (6 g/day) and decreased serum total protein (5.8 g/dL) and albumin (1.6 g/dL) levels, indicating nephrotic syndrome. Percutaneous renal biopsy revealed membranoproliferative glomerulonephritis (MPGN) in the acute stage and AA amyloidosis of mild degree. AA amyloidosis was also diagnosed histologically on gastric and colonic biopsy, in addition to renal biopsy. His renal function decreased gradually, and therefore, he underwent hemodialysis therapy in January 2012. However, his gastrointestinal-related symptoms persisted, and his appetite diminished, because of which he had become severely malnourished; he died 8 months later. This is a rare case of a patient with two different renal lesions (MPGN and AA amyloidosis) complicated with NTM. Our case suggests that MPGN and amyloidosis should be considered in elderly patients with nephrotic syndrome onset and chronic inflammation.