Pulmonary alveolar proteinosis and pulmonary cryptococcosis in an adolescent boy

Of Mycelium and Men: Inherent Human Susceptibility to Fungal Diseases

In medical mycology, the main context of disease is iatrogenic-based disease. However, historically, and occasionally, even today, fungal diseases affect humans with no obvious risk factors, sometimes in a spectacular fashion. The field of “inborn errors of immunity” (IEI) has deduced at least some of these previously enigmatic cases; accordingly, the discovery of single-gene disorders with penetrant clinical effects and their immunologic dissection have provided a framework with which to understand some of the key pathways mediating human susceptibility to mycoses. By extension, they have also enabled the identification of naturally occurring auto-antibodies to cytokines that phenocopy such susceptibility. This review provides a comprehensive update of IEI and autoantibodies that inherently predispose humans to various fungal diseases.

Complete remission of pulmonary alveolar proteinosis after anti-tuberculous chemotherapy: a case report

Pulmonary alveolar proteinosis (PAP) is a rare respiratory system disorder. Patients with PAP are at risk for a wide variety of secondary infections. This current case report describes a patient with PAP complicated by tuberculosis. A 48-year-old male patient with multiple follow-up chest computed tomography scans that showed predominant diffuse ground glass opacity in both lung fields, presented a few years later with new calcified lesions and pleural effusion. At this point, the associated auxiliary examination indicated the possibility of PAP combined with tuberculosis infection. The patient achieved complete remission after anti-tuberculosis treatment. PAP is an easily overlooked clinical syndrome due to its low prevalence and lack of specific clinical manifestations, especially when combined with other pulmonary lesions. Therefore, clinicians should consider this rare disease in patients presenting with pulmonary disease and plan for its co-morbidity with other secondary outcomes, such as opportunistic infections, which are a common and life-threatening complication in patients with PAP. This case indicates the possibility that anti-tuberculosis therapy can improve alveolar proteinosis in patients with PAP and secondary Mycobacterium tuberculosis infection.

Artificial stone-associated silicosis with concurrent Cryptococcus infection

Acute silicoproteinosis is a disease that develops in weeks, and lasting for years, after massive exposure to silica dust in relatively closed spaces. It was rare, but the cases have recently increased worldwide due to the development of artificial stone industry. Compared with traditional silicosis, artificial stone-associated silicosis is more rapidly progressive and lethal. Hence, a correct diagnosis and optimal treatment are crucial. Here, we present the clinical course of a 33-year-old artificial stonemason who suffered from acute silicoproteinosis with concurrent Cryptococcus infection resulting in profound respiratory failure. This patient was treated by bronchoscope-assisted therapeutic segmental lung lavage and antifungal agent, under mechanical ventilator and ECMO support and recovered well. A brief review of acute silicoproteinosis and artificial stone-associated silicosis is also presented and highlights the new form of industry exposure to silica.

An updated review on phenocopies of primary immunodeficiency diseases

Primary immunodeficiency diseases (PIDs) refer to a heterogenous group of disorders characterized clinically by increased susceptibility to infections, autoimmunity and increased risk of malignancies.

These group of disorders present with clinical manifestations similar to PIDs with known genetic defects but have either no genetic defect or have a somatic mutation and thus have been labelled as “Phenocopies of PIDs”. These diseases have been further subdivided into those associated with somatic mutations and those associated with presence of auto-antibodies against various cytokines.

In this review, we provide an update on clinical manifestations, diagnosis and management of these diseases.

Characterization and outcomes of pulmonary alveolar proteinosis in Brazil: a case series

OBJECTIVE

Pulmonary alveolar proteinosis (PAP) is a rare disease, characterized by the alveolar accumulation of surfactant, which is composed of proteins and lipids. PAP is caused by a deficit of macrophage activity, for which the main treatment is whole-lung lavage (WLL). We report the experience at a referral center for PAP in Brazil.

METHODS

This was a retrospective study involving patients with PAP followed between 2002 and 2016. We analyzed information regarding clinical history, diagnostic methods, treatments, and outcomes, as well as data on lung function, survival, and complications.

RESULTS

We evaluated 12 patients (8 of whom were women). The mean age was 41 ± 15 years. Most of the patients were diagnosed by means of BAL and transbronchial biopsy. The mean number of WLLs performed per patient was 2.8 ± 2.5. One third of the patients never underwent WLL. Four patients (33.3%) had associated infections (cryptococcosis, in 2; nocardiosis, in 1; and tuberculosis, in 1), and 2 (16.6%) died: 1 due to lepidic adenocarcinoma and 1 due to complications during anesthesia prior to WLL. When we compared baseline data with those obtained at the end of the follow-up period, there were no significant differences in the functional data, although there was a trend toward an increase in SpO2. The median follow-up period was 45 months (range, 1-184 months). The 5-year survival rate was 82%.

CONCLUSIONS

To our knowledge, this is the largest case series of patients with PAP ever conducted in Brazil. The survival rate was similar to that found at other centers. For symptomatic, hypoxemic patients, the treatment of choice is still WLL. Precautions should be taken in order to avoid complications, especially opportunistic infections.

Pulmonary alveolar proteinosis following cryptococcal meningitis: a possible cause?

Autoimmune pulmonary alveolar proteinosis (PAP) is a rare interstitial lung disease characterised by the presence of granulocyte macrophage colony-stimulating factor (GM-CSF) autoantibodies. A man with no history of infection developed cryptococcal meningitis and a right parahilar cryptococcal mass. Antifungal treatment led to infection control, although there was presence of neurological sequelae. After 3 years, thoracic CT revealed bilateral ground glass opacities and a crazy paving pattern. Transparietal needle biopsy showed proteinaceous alveolar deposits, confirming the diagnosis of PAP. A high titre of serum anti-GM-CSF autoantibodies was found. No specific treatment was started, and radiological lesions decreased progressively. Cryptococcal infection may occur in PAP and in patients with anti-GM-CSF antibodies without PAP. These antibodies dysregulate phagocytosis in monocytes and macrophages, possibly leading to opportunistic infections in previously healthy subjects.

Local GM-CSF-Dependent Differentiation and Activation of Pulmonary Dendritic Cells and Macrophages Protect against Progressive Cryptococcal Lung Infection in Mice

Patients with acquired deficiency in GM-CSF are susceptible to infections with Cryptococcus neoformans and other opportunistic fungi. We previously showed that GM-CSF protects against progressive fungal disease using a murine model of cryptococcal lung infection. To better understand the cellular and molecular mechanisms through which GM-CSF enhances antifungal host defenses, we investigated temporal and spatial relationships between myeloid and lymphoid immune responses in wild-type C57BL/6 mice capable of producing GM-CSF and GM-CSF-deficient mice infected with a moderately virulent encapsulated strain of C. neoformans (strain 52D). Our data demonstrate that GM-CSF deficiency led to a reduction in: 1) total lung leukocyte recruitment; 2) Th2 and Th17 responses; 3) total numbers of CD11b(+) dendritic cells (DC) and CD11b(-) and CD11b(+) macrophages (Mϕ); 4) DC and Mϕ activation; and 5) localization of DC and Mϕ to the microanatomic sites of alveolar infection. In contrast, GM-CSF deficiency resulted in increased accumulation of DC and Mϕ precursors, namely Ly-6C(high) monocytes, in the blood and lungs of infected mice. Collectively, these results show that GM-CSF promotes the local differentiation, accumulation, activation, and alveolar localization of lung DC and Mϕ in mice with cryptococcal lung infection. These findings identify GM-CSF as central to the protective immune response that prevents progressive fungal disease and thus shed new light on the increased susceptibility to these infections observed in patients with acquired GM-CSF deficiency.

Post-infectious inflammatory response syndrome (PIIRS): Dissociation of T-cell-macrophage signaling in previously healthy individuals with cryptococcal fungal meningoencephalitis

Cryptococcus is an important cause of central nervous system infections in both immunocompromised patients such as those with HIV/AIDS as well as previously healthy individuals. Deficiencies in T-cell activation are well-known to be highly associated with host susceptibility in HIV/AIDS as well in animal modeling studies, resulting in poor microbiological control and little host inflammation. However, recent studies conducted in human patients have demonstrated roles for macrophage signaling defects as an important association with disease susceptibility. For example, an autoantibody to granulocyte monocyte stimulating factor (GMCSF) resulted in defective STAT5 signaling and susceptibility to cryptococcosis. In addition, severe cases of cryptococcal meningo-encephalitis in previously healthy patients, with or without anti-GMCSF autoantibody, developed a highly activated intrathecal T-cell population but had defects in effective macrophage polarization. Intrathecal inflammation correlated with neurological damage, measured by the axonal damage protein, neurofilament light chain 1. Based on these studies, we propose a new syndrome of cryptococcal post-infectious inflammatory response syndrome (PIIRS) defined in previously healthy patients with cryptococcal meningo-encephalitis as the presence of a poor clinical response in the setting of at least 1 month of amphotericin-based fungicidal therapy and sterile cerebrospinal cultures. These findings are discussed in light of the potential for improving therapy.

Is Cryptococcus gattii a Primary Pathogen?

The two etiologic agents of cryptococcal meningoencephalitis, Cryptococcus neoformans and C. gattii, have been commonly designated as either an opportunistic pathogen for the first species or as a primary pathogen for the second species. Such a distinction has been based on epidemiological findings that the majority of patients presenting meningoencephalitis caused by C. neoformans are immunocompromised while C. gattii infection has been reported more often in immunocompetent patients. A recent report, however, showed that GM-CSF (granulocyte-macrophage colony-stimulating factor) neutralizing antibodies were prevalent in the plasma of "apparently immunocompetent" C. gattii patients with meningoencephalitis. Because GM-CSF is essential for differentiation of monocytes to macrophages and modulating the immune response, it is not surprising that the lack of GM-CSF function predisposes otherwise healthy individuals to infection via inhalation of environmental pathogens such as C. gattii. Since the test for anti-GM-CSF autoantibodies is not included in routine immunological profiling at most hospitals, healthy patients with GM-CSF neutralizing antibodies are usually categorized as immunocompetent. It is likely that a comprehensive immunological evaluation of patients with C. gattii meningoencephalitis, who had been diagnosed as immunocompetent, would reveal a majority of them had hidden immune dysfunction. This paper reviews the relationship between GM-CSF neutralizing antibodies and the risk for C. gattii infection with CNS involvement.

Anti-GM-CSF autoantibodies in patients with cryptococcal meningitis

Cryptococcal meningitis has been described in immunocompromised patients, as well as in those for whom no immune defect has been identified. GM-CSF regulates the function of phagocytes and pulmonary alveolar macrophages, critical elements in cryptococcal control. We performed clinical histories, immunological evaluation, and anticytokine autoantibody screening in four current patients with cryptococcal meningitis and identified and tested 103 archived plasma/cerebrospinal fluid samples from patients with cryptococcal meningitis. We assessed the ability of anti-GM-CSF autoantibody-containing plasmas to inhibit GM-CSF signaling. We recognized anti-GM-CSF autoantibodies in an otherwise healthy female with cryptococcal meningitis who later developed pulmonary alveolar proteinosis (PAP). Her diagnosis prompted screening of patients with cryptococcal meningitis for anticytokine autoantibodies. We identified seven HIV-negative patients with cryptococcal meningitis who tested positive for high-titer anti-GM-CSF autoantibodies. Two of the seven later developed evidence of PAP. Plasma from all patients prevented GM-CSF-induced STAT5 phosphorylation and MIP-1α production in normal PBMCs. This effect was limited to their IgG fraction. Anti-GM-CSF autoantibodies are associated with some cases of cryptococcal meningitis in otherwise immunocompetent patients. These cases need not have associated PAP.

Anticytokine autoantibodies in infectious diseases: pathogenesis and mechanisms

Autoantibodies to cytokines occur in many different conditions and situations and can cause a wide range of disease, including pulmonary alveolar proteinosis, disseminated non-tuberculous mycobacterial disease, pure red-cell aplasia, and chronic mucocutaneous candidiasis. Anticytokine autoantibodies may also develop against exogenously administered cytokines, sometimes diminishing their effects or inhibiting the activity of the endogenous cytokine. Unlike primary congenital immunodeficiencies, autoantibodies may develop over time, wax and wane, and may change in titre or avidity. Naturally occurring autoantibodies to interferons α, β, and γ, interleukins 1α, 2, 6, and 10, tumour necrosis factor, and granulocyte-macrophage colony-stimulating factor have been reported in healthy individuals and have been identified in rheumatological diseases, graft-versus-host disease, and cancer. Therapeutic antibodies, growth factors, other biological agents, and cytokines used to treat acute, chronic, malignant, and immune diseases may elicit or overcome autoantibodies, hence influencing the primary intended therapy. The increasing number of biologically active anticytokine autoantibodies being reported suggests that currently "idiopathic" diseases may someday be explained by neutralising or agonising autoantibodies. Their protean roles in causing, treating, preventing, and responding to disease, as well as simply maintaining normal homoeostasis, offer fascinating insights into the biology of immunity, inflammation, and infection.

Immunodeficiency secondary to anticytokine autoantibodies

PURPOSE OF REVIEW

Anticytokine autoantibodies are an important and emerging mechanism of disease pathogenesis. We will review the clinical and laboratory features of syndromes in which immunodeficiency is caused by or associated with neutralizing anticytokine autoantibodies.

RECENT FINDINGS

A growing number of patients have been described who demonstrate unique infectious phenotypes associated with neutralizing autoantibodies that target a particular cytokine known to participate in host defense against the offending organism. Examples include antigranulocyte macrophage-colony stimulating factor (GM-CSF) autoantibodies and pulmonary alveolar proteinosis; anti-interferon (IFN)-γ autoantibodies and disseminated nontuberculous mycobacteria (NTM); anti-interleukin-(IL)-6 autoantibodies and severe staphylococcal skin infection; anti-IL-17A, anti-IL-17F, or anti-IL-22 autoantibodies in patients with mucocutaneous candidiasis in the setting of both the autoimmune polyendocrinopathy, candidiasis, ectodermal dystrophy (APECED) syndrome and in cases of thymoma.

SUMMARY

Anticytokine autoantibodies have manifestations that are diverse, ranging from asymptomatic to life-threatening. These emerging and fascinating causes of acquired immunodeficiency may explain some previously idiopathic syndromes.

Pulmonary alveolar proteinosis: progress in the first 44 years

Pulmonary alveolar proteinosis is a rare clinical syndrome that was first described in 1958. Subsequently, over 240 case reports and small series have described at least 410 cases in the literature. Characterized by the alveolar accumulation of surfactant components with minimal interstitial inflammation or fibrosis, pulmonary alveolar proteinosis has a variable clinical course ranging from spontaneous resolution to death with pneumonia or respiratory failure. The most effective proven treatment--whole lung lavage--was described soon after the first recognition of this disease. In the last 8 years, there has been rapid progress toward elucidation of the molecular mechanisms underlying both the congenital and acquired forms of pulmonary alveolar proteinosis, following serendipitous discoveries in gene-targeted mice lacking granulocyte-macrophage colony-stimulating factor (GM-CSF). Impairment of surfactant clearance by alveolar macrophages as a result of inhibition of the action of GM-CSF by blocking autoantibodies may underlie many acquired cases, whereas congenital disease is most commonly attributable to mutations in surfactant protein genes but may also be caused by GM-CSF receptor defects. Therapy with GM-CSF has shown promise in approximately half of those acquired cases treated, but it is unsuccessful in congenital forms of the disease, consistent with the known differences in disease pathogenesis.

Childhood pulmonary alveolar proteinosis. Extracorporeal membrane oxygenation with total cardiopulmonary support during bronchopulmonary lavage

Partial cardiopulmonary bypass with extracorporeal membrane oxygenation to allow bilateral bronchopulmonary lavage in pulmonary alveolar proteinosis has been described. However, this technique is complicated by a very low arterial PO2 and cardiovascular embarrassment. Total cardiopulmonary support avoids these problems and was successfully used in a 2 1/2-year-old girl.

Surfactant protein B deficiency: radiographic manifestations

Surfactant is a complex structure primarily composed of phospholipids, but containing essential proteins as well. Congenital deficiency of Surfactant Protein-B (SPB) has recently been documented for the first time in two siblings. The pathologic findings in these infants was that of congenital pulmonary alveolar proteinosis and the radiographic manifestations were strikingly similar to hyaline membrane disease.

Pulmonary alveolar proteinosis: successful treatment with aerosolized trypsin

A 37 year old man with pulmonary alveolar proteinosis and severe pulmonary physiologic impairment was treated empirically for 12 months with continuous oxygen, intermittent positive pressure breathing and aerosolized saline solution, heparin and acetylcysteine. Because of progression of disease, he was treated with aerosolized trypsin in a dose of 100,000 U twice daily for six months. This treatment was associated with dramatic symptomatic, chest roentgenographic and pulmonary physiologic improvement that has lasted for two and a half years without remission. The absence of adverse effects of trypsin aerosol allowed its administration in the patient's home. It is suggested that the preferred initial therapy for symptomatic alveolar proteinosis is aerosolized trypsin.

Pulmonary alveolar proteinosis and histoplasmosis: report of three cases

Pulmonary alveolar proteinosis (PAP), in addition to acute generalized histoplasmosis, was found at autopsy of three adult males, 23, 51, and 52 years of age. All three patients became ill in the same region of Venezuela, south of Lake Maracaibo, an area considered highly endemic for histoplasmosis. The PAP may be due to an environmental factor.