Exploring the role of point-of-care ultrasound for people with HIV in a resource affluent setting: A prospective observational study

BACKGROUND

In low resource settings point of care ultrasound (POCUS) has proven value for the detection of opportunistic diseases in HIV, especially tuberculosis. Few studies have explored POCUS in people with HIV and potential opportunistic infections in resource affluent settings.

METHODS

We performed a prospective observational study in the Netherlands. Outpatients newly diagnosed with HIV and a CD4 T-cell count below 350 cells/mm3 and inpatients with HIV on the infectious diseases ward were included. POCUS of chest and abdomen were performed to detect opportunistic diseases and patients were followed for 1 year to register the presence or absence of opportunistic diseases as detected during routine care. Primary outcome was the number of HIV-related and unrelated conditions detected by POCUS and interobserver variation (ClinicalTrials.gov registration NCT04246983).

RESULTS

We included 34 patients (79% males, median CD4 T-cell count 115/mm3). Observers had 97.5% agreement (Cohen's kappa for interobserver reliability 0.75). POCUS examination indicated at least one new opportunistic disease in 11 patients. In all these patients additional investigations confirmed opportunistic disease, predominantly Pneumocystis jirovecii pneumonia, bacterial pneumonia, Mycobacterium avium complex infection and lymphoma. In four patients an opportunistic disease was diagnosed in foci inaccessible for POCUS and a normal POCUS correctly excluded opportunistic diseases of the investigated structures in all patients, yielding a sensitivity of 73% and a specificity of 100%.

CONCLUSIONS

POCUS can be a reliable, valuable addition to physical examination of people with HIV and advanced immune suppression. The data support further exploration of POCUS in people with HIV in resource affluent settings.

Antigen-specific cytokine profiles for pulmonary Mycobacterium avium complex disease stage diagnosis

Introduction

Controlling pulmonary Mycobacterium avium complex (MAC) disease is difficult because there is no way to know the clinical stage accurately. There have been few attempts to use cell-mediated immunity for diagnosing the stage. The objective of this study was to characterize cytokine profiles of CD4+T and CD19+B cells that recognize various Mycobacterium avium-associated antigens in different clinical stages of MAC.

Methods

A total of 47 MAC patients at different stages based on clinical information (14 before-treatment, 16 on-treatment, and 17 after-treatment) and 17 healthy controls were recruited. Peripheral blood mononuclear cells were cultured with specific antigens (MAV0968, 1160, 1276, and 4925), and the cytokine profiles (IFN-γ, TNF-α, IL-2, IL-10, IL-13, and IL-17) of CD4+/CD3+ and CD19+ cells were analyzed by flow cytometry.

Results

The response of Th1 cytokines such as IFN-γ and TNF-α against various antigens was significantly higher in both the on-treatment and after-treatment groups than in the before-treatment group and control (P < 0.01-0.0001 and P < 0.05-0.0001). An analysis of polyfunctional T cells suggested that the presence of IL-2 is closely related to the stage after the start of treatment (P = 0.0309-P < 0.0001) and is involved in memory function. Non-Th1 cytokines, such as IL-10 and IL-17, showed significantly higher responses in the before-treatment group (P < 0.0001 and P < 0.01-0.0001). These responses were not observed with purified protein derivative (PPD). CD19+B cells showed a response similar to that of CD4+T cells.

Conclusion

There is a characteristic cytokine profile at each clinical stage of MAC.

Epidemiological trends in nontuberculous mycobacterial infection among people with cystic fibrosis in Germany

OBJECTIVES

People with cystic fibrosis (pwCF) are at risk for infection with nontuberculous mycobacteria (NTM). The epidemiology and screening practice of NTM among pwCF in Germany are largely unknown and require investigation.

METHODS

We analyzed the data of the German Cystic Fibrosis Registry from 2016 to 2020 for NTM. The annual prevalence and incidence of any NTM, Mycobacterium abscessus complex (MABC), Mycobacterium avium complex (MAC), Mycobacterium gordonae, and other mycobacteria were determined and correlated to patient characteristics. Patients with incident MABC and MAC infection were compared.

RESULTS

The annual NTM prevalence and incidence remained stable between 7.53% and 8.76%, as well as 3.31% and 4.95%, respectively, among the approximately 6000 registry participants. MABC was the most common NTM, whereas only the prevalence of MAC increased slightly. In each year, only about one-third of all patients were screened for NTM. An association between NTM infections and Aspergillus fumigatus infection and/or allergic bronchopulmonary aspergillosis was observed. On average, patients with incident MAC infection were older than patients with MABC infection.

CONCLUSION

The NTM burden in pwCF in Germany remained unchanged between 2016 and 2020. MABC was the dominant species detected, whereas only MAC infections increased with time and patient age. The previously observed association of Aspergillus fumigatus and NTM was reaffirmed. Awareness of NTM needs to be improved.

"Hot Tub Lung" With M. avium complex in an Immunocompetent Adolescent

We describe a case of pulmonary Mycobacterium avium complex (MAC) infection in an immunocompetent pediatric patient after a hot tub near drowning event with a literature review of pediatric MAC-associated disease after hot tub exposure.

T-cell deficiency and hyperinflammatory monocyte responses associate with Mycobacterium avium complex lung disease

Immunological mechanisms of susceptibility to nontuberculous mycobacterial (NTM) disease are poorly understood. To understand NTM pathogenesis, we evaluated innate and antigen-specific adaptive immune responses to Mycobacterium avium complex (MAC) in asymptomatic individuals with a previous history of MAC lung disease (MACDZ). We hypothesized that Mav-specific immune responses are associated with susceptibility to MAC lung disease. We measured MAC-, NTM-, or MAC/Mtb-specific T-cell responses by cytokine production, expression of surface markers, and analysis of global gene expression in 27 MACDZ individuals and 32 healthy controls. We also analyzed global gene expression in Mycobacterium avium-infected and uninfected peripheral blood monocytes from 17 MACDZ and 17 healthy controls. We were unable to detect increased T-cell responses against MAC-specific reagents in MACDZ compared to controls, while the responses to non-mycobacteria derived antigens were preserved. MACDZ individuals had a lower frequency of Th1 and Th1* T-cell populations. In addition, MACDZ subjects had lower transcriptional responses in PBMCs stimulated with a mycobacterial peptide pool (MTB300). By contrast, global gene expression analysis demonstrated upregulation of proinflammatory pathways in uninfected and M. avium-infected monocytes, i.e. a hyperinflammatory in vitro response, derived from MACDZ subjects compared to controls. Together, these data suggest a novel immunologic defect which underlies MAC pathogenesis and includes concurrent innate and adaptive dysregulation which persists years after completion of treatment.

Comparative study of in vitro activity of tedizolid and linezolid against Mycobacterium avium complex

OBJECTIVES

The aim of this study is to compare the in vitro activity and minimal inhibitory concentration (MIC) distributions of tedizolid and linezolid against Mycobacterium avium complex (MAC) strains using a reference broth microdilution assay and a macrodilution assay with the Bactec-MGIT-960.

METHODS

A total of 37 clinical isolates of MAC were included in the study. Reference broth microdilution was performed according to CLSI guidelines in a range of concentrations from 64 to 0.064 mg/L. Macrodilution was performed with the Bactec-MGIT-960 system. The cut-off points defined by CLSI for linezolid (resistant: > 16 mg/L, intermediate: 16 mg/L, susceptible: <16 mg/L) were used to define clinical categories of this drug. Essential agreement for both linezolid and tedizolid and categorical agreement for linezolid were defined following FDA criteria.

RESULTS

The MIC₅₀ (16mg/L) and MIC₉₀ (32mg/L) values for linezolid were identical with both methods. However, the MIC₅₀ and MIC₉₀ of tedizolid by microdilution (4 mg/L and 8 mg/L, respectively) were one twofold dilution higher than by macrodilution (2 mg/L and 4 mg/L, respectively). Ninety-four percent and 2.7% of the strains had MICs of tedizolid ≤4 mg/L and ≤ 0.5 mg/L, respectively, by the reference method. The linezolid macrodilution assay showed a categorical agreement of 40.5%, a minor error rate of 56.7% and a major error rate of 2.7% with respect to the reference method.

CONCLUSIONS

Tedizolid showed higher in vitro activity than linezolid against the tested MAC isolates. Macrodilution using the BD Bactec-MGIT-960 system is a practical approach to determine the susceptibility of MAC strains to tedizolid.

Pyruvate Supports RET-Dependent Mitochondrial ROS Production to Control Mycobacterium avium Infection in Human Primary Macrophages

Macrophages deploy a variety of antimicrobial programs to contain mycobacterial infection. Upon activation, they undergo extensive metabolic reprogramming to meet an increase in energy demand, but also to support immune effector functions such as secretion of cytokines and antimicrobial activities. Here, we report that mitochondrial import of pyruvate is linked to production of mitochondrial ROS and control of Mycobacterium avium (M. avium) infection in human primary macrophages. Using chemical inhibition, targeted mass spectrometry and single cell image analysis, we showed that macrophages infected with M. avium switch to aerobic glycolysis without any major imbalances in the tricarboxylic acid cycle volume or changes in the energy charge. Instead, we found that pyruvate import contributes to hyperpolarization of mitochondria in infected cells and increases production of mitochondrial reactive oxygen species by the complex I via reverse electron transport, which reduces the macrophage burden of M. avium. While mycobacterial infections are extremely difficult to treat and notoriously resistant to antibiotics, this work stresses out that compounds specifically inducing mitochondrial reactive oxygen species could present themself as valuable adjunct treatments.

Direct Attachment with Erythrocytes Augments Extracellular Growth of Pathogenic Mycobacteria

Pathogenic intracellular mycobacteria, such as Mycobacterium tuberculosis and Mycobacterium avium, which cause lung diseases, can grow in macrophages. Extracellular mycobacteria have been reported in the lungs, blood, and sputum of patients, indicating the involvement of these pathogens in disease progression. Erythrocytes are involved in the symptoms associated with pulmonary mycobacterial diseases, such as bloody sputum and hemoptysis; however, little attention has been paid to the role of erythrocytes in mycobacterial diseases. Herein, we found that Mycobacterium avium subsp. hominissuis (MAH) and Mycobacterium intracellulare colocalized with erythrocytes at the sites of lung infection, inside capillaries and necrotic areas of granulomas, using histopathological examinations. Electron microscopy showed that MAH adhered and entered human erythrocytes when they were cocultured in vitro. MAH adhered to erythrocytes through complement receptor 1 and cell-surface sialo-glycoproteins. Importantly, MAH grew vigorously without causing any pronounced damage to erythrocytes. This erythrocyte-mediated enhancement of MAH growth occurred extracellularly depending on its direct attachment to erythrocytes. In contrast, MAH failed to multiply inside erythrocytes. Similarly, erythrocytes augmented the growth of other pathogenic mycobacteria, such as M. intracellulare and M. tuberculosis. THP-1 cell-derived human macrophages preferentially phagocytosed erythrocytes that were attached to mycobacteria (compared to bacteria alone), suggesting that erythrocyte-attached mycobacteria are an efficient infectious source for macrophages. Our findings provide new insights into the pathogenesis of mycobacterial diseases and offer an alternative and useful strategy for treating mycobacterial disease. IMPORTANCE Pathogenic mycobacteria, such as Mycobacterium tuberculosis, Mycobacterium avium subsp. hominissuis (MAH), and Mycobacterium intracellulare, cause pulmonary infections as intracellular parasites of lung macrophages and epithelial cells. Here, using histopathological examinations we found that MAH and M. intracellulare colocalized with erythrocytes in lung infection sites. Subsequent studies demonstrated that direct interaction with erythrocytes enhances the extracellular proliferation of mycobacteria based on the following results: 1. MAH adhered and invaded human erythrocytes upon coculture in vitro; 2. MAH adhered to erythrocytes through complement receptor 1 and cell-surface sialo-glycoproteins; 3. MAH rapidly proliferated when directly attached to erythrocytes but not within them; 4. other mycobacteria, such as M. intracellulare and M. tuberculosis, also proliferated in the same way as MAH. The finding that pathogenic mycobacteria grow extracellularly in an erythrocyte-dependent manner is of considerable clinical importance for understanding disease progression and latent infection.

Kimidinomycin, a new antibiotic against Mycobacterium avium complex, produced by Streptomyces sp. KKTA-0263

During our screening for antibiotics against Mycobacterium avium complex (MAC) with a mass spectrometry network-based indexing approach, a new compound named kimidinomycin was isolated from the culture broth of Streptomyces sp. KKTA-0263 by solvent extraction, HP20 column chromatography, and preparative HPLC. From the structural elucidation, the compound possesses a 38-membered macrolide structure with an N-methylguanidyl group at the terminal side chain. The compound exhibited antimycobacterial activity against M. avium, M. intracellulare, M. smegmatis, and M. bovis BCG with respective MIC values of 12.5, 0.78, 12.5, and 25.0 µg ml-1.

Clinical and Immunologic Predictors of Mycobacterium avium Complex Immune Reconstitution Inflammatory Syndrome in a Contemporary Cohort of Patients With Human Immunodeficiency Virus

BACKGROUND

People with human immunodeficiency virus (HIV) can present with new or worsening symptoms associated with Mycobacterium avium complex (MAC) infection shortly after antiretroviral therapy (ART) initiation as MAC immune reconstitution inflammatory syndrome (MAC-IRIS). In this study, we assessed the utility of several laboratory tests as predictors of MAC-IRIS.

METHODS

People with HIV with clinical and histologic and/or microbiologic evidence of MAC-IRIS were identified and followed up to 96 weeks post-ART initiation within a prospective study of 206 ART-naive patients with CD4 <100 cells/µL.

RESULTS

Fifteen (7.3%) patients presented with MAC-IRIS within a median interval of 26 days after ART initiation. Patients who developed MAC-IRIS had lower body mass index, lower hemoglobin levels, higher alkaline phosphatase (ALP), and increased CD38 frequency and mean fluorescence intensity on CD8+ T cells at the time of ART initiation compared with non-MAC IRIS patients. A decision tree inference model revealed that stratifying patients based on levels of ALP and D-dimer could predict the likelihood of MAC-IRIS. A binary logistic regression demonstrated that higher levels of ALP at baseline were associated with increased risk of MAC-IRIS development.

CONCLUSIONS

High ALP levels and increased CD8+ T-cell activation with low CD4 counts at ART initiation should warrant suspicion for subsequent development of MAC-IRIS.

Human health risks for Legionella and Mycobacterium avium complex (MAC) from potable and non-potable uses of roof-harvested rainwater

A quantitative microbial risk assessment (QMRA) of opportunistic pathogens Legionella pneumophila (LP) and Mycobacterium avium complex (MAC) was undertaken for various uses of roof-harvested rainwater (RHRW) reported in Queensland, Australia to identify appropriate usages and guide risk management practices. Risks from inhalation of aerosols due to showering, swimming in pools topped up with RHRW, use of a garden hose, car washing, and toilet flushing with RHRW were considered for LP while both ingestion (drinking, produce consumption, and accidental ingestion from various activities) and inhalation risks were considered for MAC. The drinking water route of exposure presented the greatest risks due to cervical lymphadenitis and disseminated infection health endpoints for children and immune-compromised populations, respectively. It is therefore not recommended that these populations consume untreated rainwater. LP risks were up to 6 orders of magnitude higher than MAC risks for the inhalation route of exposure for all scenarios. Both inhalation and ingestion QMRA simulations support that while drinking, showering, and garden hosing with RHRW may present the highest risks, car washing and clothes washing could constitute appropriate uses of RHRW for all populations, and toilet flushing and consumption of lettuce irrigation with RHRW would be appropriate for non- immune-compromised populations.

Dose response models and a quantitative microbial risk assessment framework for the Mycobacterium avium complex that account for recent developments in molecular biology, taxonomy, and epidemiology

Mycobacterium avium complex (MAC) is a group of environmentally-transmitted pathogens of great public health importance. This group is known to be harbored, amplified, and selected for more human-virulent characteristics by amoeba species in aquatic biofilms. However, a quantitative microbial risk assessment (QMRA) has not been performed due to the lack of dose response models resulting from significant heterogeneity within even a single species or subspecies of MAC, as well as the range of human susceptibilities to mycobacterial disease. The primary human-relevant species and subspecies responsible for the majority of the human disease burden and present in drinking water, biofilms, and soil are M. avium subsp. hominissuis, M. intracellulare, and M. chimaera. A critical review of the published literature identified important health endpoints, exposure routes, and susceptible populations for MAC risk assessment. In addition, data sets for quantitative dose-response functions were extracted from published in vivo animal dosing experiments. As a result, seven new exponential dose response models for human-relevant species of MAC with endpoints of lung lesions, death, disseminated infection, liver infection, and lymph node lesions are proposed. Although current physical and biochemical tests used in clinical settings do not differentiate between M. avium and M. intracellulare, differentiating between environmental species and subspecies of the MAC can aid in the assessment of health risks and control of MAC sources. A framework is proposed for incorporating the proposed dose response models into susceptible population- and exposure route-specific QMRA models.

Care of Patients With HIV Infection: Medical Complications and Comorbidities

Care of patients with HIV infection starts with diagnosis as soon as possible, preferably at or near the time of acute infection. Opportunistic infections, malignancies, and other conditions develop progressively over time, particularly in untreated patients. The AIDS-defining opportunistic infections most common in the United States include Pneumocystis jirovecii pneumonia, Candida esophagitis, toxoplasmic encephalitis, tuberculosis, disseminated Mycobacterium avium complex, cryptococcal meningitis, and cytomegalovirus retinitis. Specific prophylaxis regimens exist for several opportunistic infections, and effective antiretroviral therapy reduces the risk of most others. Other AIDS-defining conditions include wasting syndrome and HIV encephalopathy. AIDS-defining malignancies include Kaposi sarcoma, systemic non-Hodgkin lymphoma, primary central nervous system lymphoma, and invasive cervical cancer. Although not an AIDS-defining condition, anal cancer is common in patients with HIV infection. Other HIV-related conditions include thrombocytopenia, recurrent bacterial respiratory infections, HIV-associated nephropathy, and HIV-associated neurocognitive disorder.

Osteomyelitis and arthritis of the wrist caused by Mycobacterium intracellulare in an immunocompetent patient: a case report and literature review

Mycobacterium intracellulare causes infection in humans. Involvement of joint and bone, however, is extremely rare. We present the case of an immunocompetent 67-year-old female with chronic swelling of the wrist joint diagnosed as rheumatoid arthritis by her previous physician. Examination revealed an unclosed fistula associated with a puncture, and bone and joint destruction on radiographs. She was diagnosed with osteomyelitis and arthritis due to M. intracellulare on histological and microbiological examinations. She was successfully treated with radical surgical debridement and anti-tuberculous drugs for 1 year and there was no recurrence at 3 years postoperatively.

[Immunological background on non-tuberculous mycobacteriosis]

Nontuberculous mycobacteria (NTM) pulmonary disease is increasing and Mycobacterium avium complex (MAC) is the most common cause. NTM pulmonary disease has been linked in a distinct patient phenotype such as thin, post-menopausal women. Their predisposition to infection with NTM suggests that immunologic responses to NTM potentially contribute to pathogenesis of NTM lung disease. In this symposium, we asked four speakers to talk mainly about the immunologic pathogenesis. The topics included immunosuppressive macrophages in patients infected with MAC, pathological findings of MAC pulmonary disease, poor nutrition conditions associated with the progressive NTM pulmonary disease, and hypersensitivity reaction referred to as "hot tub lung". We hope that the discussion through this symposium will lead to clinical usefulness of this disease.

[Two cases of Mycobacterium avium complex pleuritis]

We encountered 2 cases of Mycobacterium avium complex pleuritis. One case was a 68-year-old woman suffering from rheumatoid arthritis, treated with steroids. She presented to our hospital with dyspnea, which improved after a chest tube insertion and the administration of rifampicin, ethambutol, clarithromycin, and streptomycin. In the other case, a 71-year-old man suffering from nephritic syndrome and who had been treated with steroids presented to our hospital with low-grade fever and dyspnea. He improved after therapeutic thoracentesis and clarithromycin administration. Only 6 cases of Mycobacterium avium complex pleuritis have been reported; because it is rare, the characteristics and prognosis of the disease remain unknown. We report 2 cases and review 6 previous reports of Mycobacterium avium complex pleuritis.

[A case of Mycobacterium intracellulare infection with chronic empyema]

A 83-year-old man had been treated for pulmonary infiltration was referred to a nearby hospital because of slight fever and cough. His chest radiograph and CT showed right chronic empyema, and in which pleural aspirate was smear positive for acid-fast bacilli and positive for PCR-Mycobacterium intracellulare. He was diagnosed as chronic empyema caused by M. intracellulare. A month later exacerbation of bronchopleural fistula was observed and M. intracellulare infection expanded into the lung. He was treated with combined use of ethambutol, rifampicin, clarithromycin, and streptomycin for six months, and his chest radiograph showed improvement, however, finally he died as he was in advanced age and emaciation due to chronic lung infection.

The in vitro activity of phenothiazines against Mycobacterium avium: potential of thioridazine for therapy of the co-infected AIDS patient

Patients presenting with Acquired Immune Deficiency Syndrome (AIDS) are predisposed to co-infection with Mycobacterium avium. The management of such patients is problematic due to underlying immuno-incompetence and the high resistance of M. avium to most non-toxic compounds. Therefore, the need for effective agents is obvious. Because phenothiazines, especially the relatively mild thioridazine, have significant activity against Mycobacterium tuberculosis, we investigated the in vitro activity of chlorpromazine, thioridazine, promazine, promethazine and desipramine against a reference and clinical strains of M. avium. The results obtained show that whereas all of the phenothiazines employed in this study had an minimum inhibitory concentration (MIC) against the strains studied that ranged from ca. 10 to > 50 mg/L, as was previously shown for M. tuberculosis, thioridazine was the most active of the group against M. avium.

Characterization of Functional, Radiologic and Lung Function Recovery Post-Treatment of Hot Tub Lung. A Case Report and Review of the Literature

Hot tub lung is described as an acute pulmonary illness that is characterized by fever, dyspnea and interstitial nodular infiltrates. Although not entirely clear, the etiology may be a hypersensitivity pneumonitis, an infection secondary to Mycobacterium avium intracellulare (MAC), or possibly both. Herein we describe the most well-characterized physiologic, radiographic, and functional recovery from hot tub lung reported in the literature to date. Pulmonary function testing and CT scans of the chest were obtained after each therapeutic intervention, and the patient had the most dramatic improvement with simply avoiding the hot tub. Prednisone therapy offered minimal further improvement while anti-MAC therapy provided no further improvement. These results are suggestive of a hypersensitivity pneumonitis rather than an infectious etiology.

Mycobacterium avium complex pulmonary disease in patients without HIV infection

Mycobacterium avium complex (MAC) is ubiquitous. It is found in various freshwater and saltwater sources around the world, including hot water pipes. Although the organism was identified in the 1890s, its potential to cause human disease was only recognized 50 years later. Only a minority of people exposed to the organism will acquire MAC lung disease, usually those with underlying lung disease or immunosuppression. MAC may, however, cause progressive parenchymal lung disease and bronchiectasis in patients without underlying lung disease, particularly in middle-aged and elderly women. Preliminary data suggest that the interferon-gamma pathways may be deficient in elderly women with MAC lung disease. Other groups of patients who are more likely to harbor MAC in their lungs include patients with a cystic fibrosis or an abnormal alpha(1)-antiproteinase gene and patients with certain chest wall abnormalities. Treatment results continue to be disappointing, and the mortality of patients with MAC lung disease remains high. A PubMed search identified 38 reports of the treatment of MAC lung disease. Apart from the British Thoracic Society study, the only published controlled investigation, the studies published since 1994 have included a macrolide, either clarithromycin or azithromycin, usually in combination with ethambutol and a rifamycin. If success is defined as eradication of the organism without relapse over a period of several years after treatment has been discontinued, the reported treatment success rate with the macrolide containing regimens is approximately 55%. The prolonged treatment period, side effects, and possibly reinfection rather than relapse are responsible for the high failure rate.

[Mycobacteria other than tuberculosis combined primary lung cancer]

From January 1997 to June 1999, we performed surgery in 17 patients with mycobacteria other than tuberculosis (MOTT), and 2 patients with lung cancer among them. Both patients had the diagnosis of MOTT by sputa bacterial cultures preoperatively, but no diagnosis of lung cancer. By computed tomography (CT) scanning, lung cancer was suspected in both patients, therefore they were performed video-assisted thoracoscopic resection of the lung. The diagnosis of malignancy was made by intraoperative frozen section of resected tissue, the patients were performed lobectomy with systematic mediiastinal lymph nodes dissection. According to increment of detection of the small peripheral lesion, infectious disease such as MOTT can be detected as small abnormal shadow by CT. However, it is difficult to distinguish malignancy from infectious disease preoperatively. Even if a preoperative diagnosis, of MOTT was made like present cases, diagnostic video-assisted thoracoscopic surgery must be performed, considering that lung cancer could combined with MOTT.

Survival in children with perinatal HIV infection and very low CD4 lymphocyte counts

OBJECTIVES

To evaluate clinical conditions associated with mortality in HIV-infected children with CD4+ counts <100 cells/microl.

METHODS

The Pediatric Spectrum of HIV Disease Project is a longitudinal medical record review study with eight study sites in the United States, which have been enrolling children since 1989. Survival time from baseline very low CD4 count (<100 cells/microl) to death was estimated using the Kaplan-Meier method. Cox proportional hazards models were used to evaluate the effect of clinical variables on mortality.

RESULTS

Of 522 children (>/=1 year of age) with serial CD4+ T-lymphocyte measurements, the median age at the first very low CD4 count was 4.8 years. The estimated median survival following the first very low CD4 count was 36 months. The following factors present at the first very low CD4 count were independently associated with a higher risk of death: younger age, weight-for-age >2 standard deviations below the mean, and previously diagnosed AIDS. The subsequent development of cytomegalovirus (CMV)-associated disease, Mycobacterium avium intracellulare (MAI) infection, wasting syndrome, or esophageal candidiasis was also independently associated with a higher risk of death.

CONCLUSION

Survival in HIV-infected children with very low CD4 counts before introduction of highly active antiretroviral therapy was highly variable. Poor nutritional status and the development of CMV disease or MAI infection were associated with the shortest survival times.

[Nontuberculous mycobacterial infection followed for 12 years]

A 67-year-old woman presented in September 1985 with productive cough, bloody sputum, and dyspnea on exertion. Productive cough and bloody sputum had developed when the patient was 55 years old. Sputum culture and radiologic findings yielded a diagnosis of nontuberculous mycobacteriosis (NTM). Antituberculous therapy with INH, RFP, and EB was initiated in November 1987 because of the development of a cavity in the right upper lobe, and led to resolution of the lesion and clinical symptoms. Despite progression of bronchiectatic changes in both lungs and a relapse of her clinical symptoms during the following 10 years, the patient retained enough pulmonary function to be able to maintain an active daily life until she died of advanced gastric cancer at the age of 79. Autopsy revealed cystic bronchiectasis accompanied by bronchial wall thickening in both lungs, with some granuloma and acid-fast-bacteria observed in lung tissue. In this report, we concluded that patients with NTM usually experience a gradual progression of symptoms and radiographic changes during their clinical course, and that their pulmonary function may be conserved well enough to maintain an active daily life.

Clinical and radiographic manifestations of uncommon pulmonary nontuberculous mycobacterial disease in AIDS patients

STUDY OBJECTIVE

To determine the clinical and radiographic findings of nontuberculous mycobacteria (NTM) other than Mycobacterium avium complex (MAC) and Mycobacterium kansasii in AIDS compared with non-AIDS patients.

DESIGN

A retrospective chart review of all patients in whom NTM other than MAC complex and M kansasii were isolated between April 1, 1989, and October 31, 1995.

SETTING

University-affiliated hospital.

PATIENTS

Fifty-four patients met the criteria for uncommon pulmonary NTM disease: (1) repeated isolation of atypical mycobacterium in colony counts of > or = 3 from two or more sputum specimens; or isolation of the organism from transbronchial or open lung biopsy specimen with histologic changes suggestive of mycobacterial disease in the absence of other pathogens; and (2) either an abnormal chest radiograph, the cause of which had not been attributed to an active infection other than atypical mycobacterial disease; or the presence of one or more symptoms indicative of pulmonary disease coupled with exclusion of other illnesses with similar symptoms and signs.

RESULTS

Thirty-five patients were HIV positive. Fever was the only clinical symptom more commonly seen in HIV-infected patients with NTM than non-HIV-infected patients. Sixty-six percent of all patients with AIDS were infected by Mycobacterium xenopi. Chest radiographs of AIDS patients showed a tendency for predominance of interstitial infiltrate and rarity of fibronodular disease. No specific radiographic pattern was observed for any particular organism. Adenopathy was not a feature of uncommon pulmonary NTM in AIDS, and it should suggest an alternate diagnosis. In two patients, NTM isolation from respiratory specimens preceded dissemination. Six of 8 AIDS patients treated for pulmonary NTM remained alive at the end of the study compared with only 4 of 15 patients who were not treated for pulmonary NTM (p<0.05).

CONCLUSIONS

Uncommon NTM isolated from respiratory specimens ought to be considered as serious pathogens in the presence of clinical and radiographic manifestations unexplained by other pathologic processes. Colonization with NTM could precede dissemination. Treatment of uncommon pulmonary NTM disease could possibly confer a survival benefit in AIDS patients.

Extension of the life table to repeating and changing events

Estimation of cumulative and adjusted occurrence of life events and measures over time is often important in settings where study subjects have incomplete or different follow-up periods. Well-known methods to do this, such as the life table and age adjustment, exist for binary nonrecurrent events (i.e., death). However, a general approach to evaluate recurrent life events (e.g., repeated infections), life events with different durations (e.g., hospitalization days), costs, or changing life measures (e.g., body weight) is not available. This paper develops the "Life-Event Table," an analog of the life table that can analyze occurrence of diverse types of events and measures when the observation periods of subjects are incomplete and different. This method, based on a central limit theorem for incomplete multivariate data, obtains point estimates and variances for cumulative incidence, age-adjusted expectation, and other quantities. Simple hypotheses tests and comparisons are possible with this approach. Three applications are presented. The Life-Event Table may facilitate use of currently available robust multivariate analysis methods. Further research into other multivariate methods that take advantage of this Life-Event Table's specific covariance/variance structure may be warranted.

Localized soft-tissue infections with Mycobacterium avium/Mycobacterium intracellulare complex in immunocompetent patients: granulomatous tenosynovitis of the hand or wrist

In immunocompetent patients, Mycobacterium avium/Mycobacterium intracellulare complex (MAC) has been associated with pulmonary infection in adults, cervical lymphadenitis in children, and disseminated infection in children and adults. MAC rarely has been recognized as a cause of localized soft-tissue infection in immunocompetent hosts. Six cases of granulomatous tenosynovitis due to MAC are reported; five cases occurred after local surgical procedures, trauma, or corticosteroid injection. In four cases, cure was achieved with combined medical and surgical intervention. In these six cases and 11 previously reported cases, both males and females were affected equally, usually in the fifth to seventh decades of life, and the distal upper extremity was predominantly involved. Surgical debridement with appropriate culture was critical for diagnosis and management. Antimycobacterial chemotherapy seemed to be a beneficial adjunctive measure in most cases but was clearly necessary for cure in only a few cases.

[Avian mycobacteria]

The avian mycobacteria have been identified first in relation to their virulence for hens. But this property was not definitely to correlate with serovars. Furthermore, this heterogenicity was to confirm on molecular level. Therefore it was necessary to introduce a M.avium complex beside true M.avium. M.avium has special relevance to AIDS patients. This fact shows that the reasons for infections by these facultatively pathogenic mycobacteria are more complicated as accepted.

[Clinical characteristics of the patients with primary infection of Mycobacterium avium complex]

Clinical characteristics are analyzed in patients with primary infection of Mycobacterium avium complex (MAC). The definition of primary infection of MAC are determined as follows; 1) MAC is found several times since the beginning of the disease, 2) clinical symptoms or abnormal shadow corresponding to MAC infection on chest roentgenogram, 3) no old tuberculous lesions nor other abnormal shadows like bronchiectasis, 4) no abnormal serological results suggesting other bacterial or viral infections. According to this definition, 17 out of 84 MAC patients are diagnosed as primary MAC infection, and clinical features are analyzed in these 17 patients. Average age of patients is 61.1 +/- 12.9 year old. This age is significantly higher than that of inpatients with pulmonary tuberculosis in our hospital, and lower than that of all MAC patients including secondary infection. Five (29.4%) are male and 12 (70.6%) are female, the ratio of male to female is 1 to 2.4. This value is significantly different with that of inpatients with pulmonary tuberculosis in our hospital who show about 3 to 1. Most of the patients complained of cough with sputum, especially of hemosputum. Eleven out of 17 patients (64.7%) complained repeated hemosputum. The frequency of hemosputum is very high compared with that of the patients with pulmonary tuberculosis (about 20%). No compromised condition was present except for a patient with Behçet's disease who are taking steroid hormone. Roentgenographic features of primary infection are those of scattered small nodular lesions in the peripheral part of the lung, thin wall cavity formation, no contraction of the diseased lung nor dislocation of the trachea.(ABSTRACT TRUNCATED AT 250 WORDS)

Tenosynovitis due to Mycobacterium avium-intracellulare: case report and a review of the literature

A 57-year-old female patient presented with a tenosynovitis due to Mycobacterium avium-intracellulare (MAI). A relapse occurred following surgical treatment, after which she was successfully treated with ansamycin and ethambutol. Previously reported cases of tenosynovitis due to MAI are reviewed and the treatment modalities are discussed.

Pacemaker infection with Mycobacterium avium complex

A 21-year-old. HIV negative, malnourished, homeless woman with congenital heart block had a pacemaker implanted at 7 years of age and multiple procedures thereafter. The most recent of these procedures was replacement of a pulse generator in the right pectoral region. Four months later she had fever, pain, and swelling over the implant site resulting from infection with mixed flora and Mycobacterium avium complex. The pacemaker system was removed by thoracotomy via a median sternotomy and a new DDD pacemaker simultaneously implanted. She was treated with systemic antibiotics--isoniazid, rifampin, ethambutol--for 2 weeks. Six months later she was healthy, pacing well, and apparently free of infection, off all medications.