Secondary pulmonary alveolar proteinosis in hematologic malignancies. Hematol Oncol Stem Cell Ther. 2014;7:127-135. [PMID: 25300566 DOI: 10.1016/j.hemonc.2014.09.003]

Autoimmune Pulmonary Alveolar Proteinosis Complicated by Myelodysplastic Syndrome

Pulmonary alveolar proteinosis (PAP) is characterized by an abnormal surfactant accumulation in peripheral air spaces. Autoimmune PAP (APAP) results from macrophage dysfunction caused by anti-granulocyte-macrophage colony-stimulating factor (GM-CSF) autoantibodies, and the presence of antibodies more than the cutoff value is specific for APAP. In contrast, secondary PAP (SPAP) does not require anti-GM-CSF autoantibodies and is complicated by other diseases, including myelodysplastic syndrome (MDS). A 73-year-old man with anemia and thrombocytopenia was diagnosed with APAP and MDS simultaneously. The measurement of serum anti-GM-CSF autoantibodies is important for the correct diagnosis and management of PAP, even with an established diagnosis of underlying SPAP-suggestive disease.

Pulmonary alveolar proteinosis in Taiwan

BACKGROUND/PURPOSE

Pulmonary alveolar proteinosis (PAP) is rare disease manifested as alveolar macrophage dysfunction and abnormal accumulation of surfactant protein in the alveoli. In this nationwide, population-based study, we investigated the epidemiology of PAP in Taiwan, and discovered the comorbidities and prognostic factors of PAP.

METHODS

From the National Health Insurance Research Database (NHIRD), we obtained comprehensive information about all patients of PAP in Taiwan between 1995 and 2013. The incidence, baseline characteristics comorbidities, and prognostic factors of PAP were investigated.

RESULTS

The annual incidence rate of PAP was around 0.79 (range: 0.49-1.17) patients per million people after 2000, and the prevalence rate was 7.96 patients per million people by the end of 2013. In total, 276 patients of PAP were identified, including 177 (64%) and 99 (36%) patients with primary and secondary PAP, respectively. The median age of diagnosis was 53.8 years. The median survival was 9.6 years after the initial PAP diagnosis, and the 5-year survival rate was 65.96%. Twenty (7%) patients received whole lung lavage (WLL) within three months after the diagnosis had significantly better survival compared to the others. Multivariable Cox regression analyses showed that elder age, secondary PAP, and malignancy were associated with poorer survival, while WLL within 3 months of diagnosis might greatly improve the survival.

CONCLUSION

We demonstrated the epidemiology of PAP in Taiwan, showing several poor prognostic factors and the potential effectiveness of WLL. Further prospective studies based on registry are warranted to improve the diagnosis and treatment of PAP.

Characteristics of hospital admissions for pulmonary alveolar proteinosis: analysis of the nationwide inpatient sample (2012-2014)

BACKGROUND

Pulmonary alveolar proteinosis (PAP) is a rare clinical syndrome involving the accumulation of lipid-rich proteinaceous material in the alveoli. There is a paucity of published studies on this condition. To better characterize the demographics, complication rates, mortality, and healthcare costs of patients hospitalized for PAP in the United States, a secondary analysis on the Hospital Cost and Utilization Project's Nationwide Inpatient Sample (NIS) was performed on patients admitted from 2012 to 2014 with a diagnosis of pulmonary alveolar proteinosis.

METHODS

Using the NIS database, a secondary analysis was performed on 500 admissions with the diagnosis "pulmonary alveolar proteinosis." The clinical variables and outcome measures extracted were: patient demographics, hospital costs, length of stay, frequency of admissions, and inpatient mortality rate.

RESULTS

Among a weighted estimate of 500 hospital admissions from 2012 to 2014, the number of PAP admissions averaged 4.7 per million. The population was predominantly male (55%) with a mean age of 41.45 (CI 38.3-44.5) from all socioeconomic levels. Inpatient mortality was calculated to be 5%, which may result from the fact that the majority of admitted patients had few or no comorbid conditions (CCI 0.72). The most common procedure performed during admission was a bronchoalveolar lavage. Mean length of stay was 6.2 days (CI 3.9-8.5) and average cost of admission was $29,932.20 (CI 13,739-46,124). Of note, 50% of these admissions were considered "elective."

CONCLUSIONS

Demographics of patients with PAP who have been hospitalized in the United States are similar to previously reported demographics from prior patient cohorts, specifically a male predominance and a mean age in the 40 s. The inpatient mortality rate of 5% we found is consistent with prior studies demonstrating good disease-specific survival rates. Notably, the cost per admission and overall annual cost associated with PAP hospitalization was calculated to be $29932.20 and $5 million respectively. This reflects the high economic cost associated with hospitalization of PAP patients, and provokes thought about ways to make treatment more cost-effective.

Successful whole lung lavage in a child with pulmonary alveolar proteinosis secondary to hematologic malignancy

Pulmonary alveolar proteinosis (PAP) describes the accumulation of surfactant in the alveolar space. Secondary PAP has been reported in a variety of diseases, and in rare cases has been associated with hematologic malignancy. Treatment for PAP is based on the underlying disease process, and may include whole lung lavage, inhaled or subcutaneous granulocyte-macrophage colony-stimulating factor, or statins. PAP secondary to hematologic malignancy has been reported to demonstrate poor response to whole lung lavage. We report a case of successful treatment of a pediatric patient with acute myeloid leukemia and secondary PAP using whole lung lavage.

Update on Diagnosis and Treatment of Adult Pulmonary Alveolar Proteinosis

Pulmonary alveolar proteinosis (PAP) is a rare pulmonary surfactant homeostasis disorder resulting in buildup of lipo-proteinaceous material within the alveoli. PAP is classified as primary (autoimmune and hereditary), secondary, congenital and unclassifiable type based on the underlying pathogenesis. PAP has an insidious onset and can, in some cases, progress to severe respiratory failure. Diagnosis is often secured with bronchoalveolar lavage in the setting of classic imaging findings. Recent insights into genetic alterations and autoimmune mechanisms have provided newer diagnostics and treatment options. In this review, we discuss the etiopathogenesis, diagnosis and treatment options available and emerging for PAP.

Progressive Dyspnea and Hypoxemia With Diffuse Pulmonary Infiltrates in a Previously Healthy Woman

CASE PRESENTATION

A 50-year-old woman presented with 3 months of cough, dyspnea, and fatigue. She also reported new fevers, night sweats, and a rash on her face and torso. On presentation she was tachycardic and tachypneic, with oxygen saturation of 81% on 2 L/min of oxygen. She was in mild respiratory distress. Results of the physical examination were remarkable for tender left cervical and axillary adenopathy and bibasilar pulmonary crackles. She had an acneiform rash on her face, chest, and back, consisting of multiple nonblanching erythematous or violaceous macules and papules (Fig 1) and had conjunctival edema. Admission laboratory test results were significant for a WBC count of 56,000, of which 79.5% were lymphocytes. Hemoglobin and platelet levels were normal. She was admitted for further management.

Beyond "Big Eaters": The Versatile Role of Alveolar Macrophages in Health and Disease

Macrophages act as immune scavengers and are important cell types in the homeostasis of various tissues. Given the multiple roles of macrophages, these cells can also be found as tissue resident macrophages tightly integrated into a variety of tissues in which they fulfill crucial and organ-specific functions. The lung harbors at least two macrophage populations: interstitial and alveolar macrophages, which occupy different niches and functions. In this review, we provide the latest insights into the multiple roles of alveolar macrophages while unraveling the distinct factors which can influence the ontogeny and function of these cells. Furthermore, we will highlight pulmonary diseases, which are associated with dysfunctional macrophages, concentrating on congenital diseases as well as pulmonary infections and impairment of immunological pathways. Moreover, we will provide an overview about different treatment approaches targeting macrophage dysfunction. Improved knowledge of the role of macrophages in the onset of pulmonary diseases may provide the basis for new pharmacological and/or cell-based immunotherapies and will extend our understanding to other macrophage-related disorders.

Mild dyspnea presenting as 'crazy-paving' on chest computed tomography

Pulmonary alveolar proteinoisis (PAP) is a rare disease characterized by accumulation of proteinaceous material in the alveolar spaces. Here, we report a case of mild dyspnea with incidental ‘crazy-paving’ pattern on chest computed tomography (CT). Further evaluation and bronchoscopy found to have PAP.

Chronic myelomonocytic leukemia-associated pulmonary alveolar proteinosis: A case report and review of literature

BACKGROUND

Pulmonary alveolar proteinosis (PAP) is a rare condition that can cause progressive symptoms including dyspnea, cough and respiratory insufficiency. Secondary PAP is generally associated with hematological malignancies including chronic myelomonocytic leukemia (CMML). To the best of our knowledge, this is the first reported case of PAP occurring secondary to CMML.

CASE SUMMARY

We report the case of a 63-year-old male who presented with a recurrent cough and gradually progressive dyspnea in the absence of fever. Based upon clinical symptoms, computed tomography findings, bone marrow aspiration, flow cytometry studies and cytogenetic analyses, the patient was diagnosed with PAP secondary to CMML. He underwent whole lung lavage in March 2016 to alleviate his dyspnea, after which he began combined chemotherapeutic treatment with decitabine and cytarabine. The patient died in January 2020 as a consequence of severe pulmonary infection.

CONCLUSION

This case offers insight regarding the mechanistic basis for PAP secondary to CMML and highlights potential risk factors.

Autoimmune pulmonary alveolar proteinosis prior to myelodysplastic syndrome

We report the first case of autoimmune pulmonary alveolar proteinosis (PAP) associated with and preceding myelodysplastic syndrome. A 74-year-old female with a history of polymyalgia rheumatica presented with six months history of progressive exertional breathlessness. Examination revealed bilateral chest crackles and exertional desaturation. A diagnosis of autoimmune PAP was made based on the presence of autoantibodies to granulocyte-macrophage colony-stimulating factor and characteristic findings on chest computed tomography, bronchoalveolar lavage, and transbronchial biopsies. Bilateral whole lung lavage was performed with prompt improvement in symptoms. Fourteen months later, she presented with new breathlessness and was diagnosed with myelodysplasia on bone marrow biopsy. No recurrence of alveolar proteinosis was detected. This case highlights the importance of follow-up and screening of patients with autoimmune PAP for haematological conditions.

Secondary pulmonary alveolar proteinosis treated by lung transplant: A case report

BACKGROUND

Pulmonary alveolar proteinosis (PAP) is a pulmonary disease characterized by disruption of surfactant homeostasis resulting in its accumulation in the alveoli. PAP is classically classified into three categories (Table 1): 1/primary (or autoimmune) with antibodies targeting the GM-CSF pathway, 2/secondary to another disease, typically a hematologic malignancy, and 3/genetic.

CASE-REPORT

A 30 year-old woman received an allogenic hematopoietic stem cell transplantation (HSCT) after treatment for acute myeloid leukemia (AML). Within the first 6 months post HSCT, she developed an ocular, oral, digestive and hepatic graft-versus-host disease associated with a mixed ventilatory defect with a very severe obstructive syndrome and a severe CO diffusion impairment. High resolution computed tomography showed a classical "crazy paving" pattern. Aspect and differential cell count of BAL were normal. All microbiological samples remained culture negative. Histo-pathological analysis of transbronchial biopsies was unremarkable. Because of the severity of the respiratory insufficiency, open-lung biopsy (OBL) could not be performed. Despite multiple immunosuppressive therapies, lung function deteriorated rapidly; the patient also developed an excavated fungal lesion unresponsive to treatment. She underwent a bilateral lung transplant 48 months after HSCT. Histo-pathological analysis of explanted lungs showed obliterative bronchiolitis (OB), diffuse PAP and invasive cavitary pulmonary aspergillosis.

CONCLUSIONS

This case illustrates the simultaneous occurrence of OB, PAP and a fungal infection in a 30-year old female patient who underwent HSCT for acute myeloid leukemia (AML). To our knowledge this is the only documented case of PAP associated with OB treated by lung transplantation.

Leukemic Involvement in the Thorax

Leukemias are malignancies in which abnormal white blood cells are produced in the bone marrow, resulting in compromise of normal bone marrow hematopoiesis and subsequent cytopenias. Leukemias are classified as myeloid or lymphoid depending on the type of abnormal cells produced and as acute or chronic according to cellular maturity. The four major types of leukemia are acute myeloid leukemia, chronic myeloid leukemia, acute lymphoblastic leukemia, and chronic lymphocytic leukemia. Clinical manifestations are due to either bone marrow suppression (anemia, thrombocytopenia, or neutropenia) or leukemic organ infiltration. Imaging manifestations of leukemia in the thorax are myriad. While lymphadenopathy is the most common manifestation of intrathoracic leukemia, leukemia may also involve the lungs, pleura, heart, and bones and soft tissues. Myeloid sarcomas occur in 5%-7% of patients with acute myeloid leukemia and represent masses of myeloid blast cells in an extramedullary location. ^©RSNA, 2019.

[Lung involvement in hematologic systemic diseases]

Pulmonary diseases can occur across the entire disease spectrum of malignant hematologic systemic diseases. Although infectious processes of the lungs are common in these immunosuppressed patient collectives, noninfectious causes account for up to half of the pulmonary manifestations found in hematologic malignancies. Besides the frequent infections including opportunistic pathogens, a broad differential diagnosis including drug-induced lung injury by cytostatic substances, cytokines, and innovative immunotherapeutic agents, rarer transfusion of blood products and intrathoracic manifestations of the hematologic malignancy itself, have to be kept in mind. Finally, vascular complications can also lead to pulmonary reactions. Early and consistent diagnostics and treatment of the bronchopulmonary, intrathoracic and vascular complications within the framwework of hematologic systemic diseases can be essential for the patient's prognosis.

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.

Managing pulmonary complications in allogeneic hematopoietic stem cell transplantation

Introduction: Progress in allogeneic hematopoietic stem cell transplantation (HSCT) procedures has been associated with improved survival in HSCT recipients. However, they have also brought to light organ-specific complications, especially pulmonary complications. In this setting, pulmonary complications are consistently associated with poor outcomes, and improved management of these complications is required. Areas covered: We review the multiple infectious and noninfectious lung complications that occur both early and late after allogeneic HSCT. This includes the description of these complications, risk factors, diagnostic approach and outcome. A literature search was performed using PubMed-indexed journals. Expert commentary: Multiple lung complications after allogeneic HSCT can be diagnosed concomitantly and require a multidisciplinary approach. A specific clinical evaluation including a precise analysis of a lung CT scan is necessary. Management of these lung complications, especially the noninfectious ones, is impaired by the lack of prospective, randomized control trials, suggesting preventive strategies should be developed.

Allogeneic Hematopoietic Stem Cell Transplantation for GATA2 Deficiency Using a Busulfan-Based Regimen

Allogeneic hematopoietic stem cell transplantation (HSCT) reverses the bone marrow failure syndrome due to GATA2 deficiency. The intensity of conditioning required to achieve reliable engraftment and prevent relapse remains unclear. Here, we describe the results of a prospective study of HSCT in 22 patients with GATA2 deficiency using a busulfan-based conditioning regimen. The study included 2 matched related donor (MRD) recipients, 13 matched unrelated donor (URD) recipients, and 7 haploidentical related donor (HRD) recipients. MRD and URD recipients received 4 days of busulfan and 4 days of fludarabine. HRD recipients received low-dose cyclophosphamide for 2 days, fludarabine for 5 days, 2 to 3 days of busulfan depending on cytogenetics, and 200 cGy total body irradiation. MRD and URD recipients received tacrolimus and short-course methotrexate for graft-versus-host disease (GVHD) prophylaxis. HRD recipients received high-dose post-transplant cyclophosphamide (PTCy) followed by tacrolimus and mycophenolate mofetil. At a median follow-up of 24 months (range, 9 to 50), 19 of 22 patients were alive with reversal of the disease phenotype and correction of the myelodysplastic syndrome, including eradication of cytogenetic abnormalities. Three patients died: 1 from refractory acute myelogenous leukemia, 1 from GVHD, and 1 from sepsis. There was a 26% incidence of grades III to IV acute GVHD in the MRD and URD groups and no grades III to IV acute GVHD in the HRD cohort. Similarly, there was a 46% incidence of chronic GVHD in the MRD and URD cohorts, whereas only 28% of HRD recipients developed chronic GVHD. Despite excellent overall disease-free survival (86%), GVHD remains a limitation using standard prophylaxis for GVHD. We are currently extending the use of PTCy to the MRD and URD cohorts to reduce GVHD.

Pulmonary alveolar proteinosis in adults: pathophysiology and clinical approach

Pulmonary alveolar proteinosis (PAP) is a diffuse lung disease that results from the accumulation of lipoproteinaceous material in the alveoli and alveolar macrophages due to abnormal surfactant homoeostasis. Identification of the granulocyte-macrophage colony-stimulating factor (GM-CSF) as an indispensable mediator of macrophage maturation and surfactant catabolism was the key discovery leading to the current understanding of the pathogenesis of most forms of PAP. Impaired GM-CSF bioavailability due to anti-GM-CSF autoimmunity is the cause of approximately 90% of adult PAP cases. Abnormal macrophage function due to endogenous or exogenous triggers, GM-CSF receptor defects, and other genetic abnormalities of surfactant production account for the remainder of causes. The usual physiological consequence of PAP is impairment of gas exchange, which can lead to dyspnoea, hypoxaemia, or even respiratory failure and death. Pulmonary fibrosis occurs occasionally in patients with PAP. For patients with moderate to severe disease, whole lung lavage is still the first-line treatment of choice. Supplemental GM-CSF is also useful, but details about indications, choice of agent, and dosing remain unclear. Other therapies, including rituximab, plasmapheresis, and lung transplantation have been described but should be reserved for refractory cases.

Secondary pulmonary alveolar proteinosis: a single-center retrospective study (a case series and literature review)

Background

Secondary pulmonary alveolar proteinosis (sPAP) is an extremely rare disease. The clinical features of sPAP patients remain to be summarizeds.

Methods

Patients pathologically diagnosed with PAP and with negative results for anti-granulocyte macrophage colony stimulating factor (GM-CSF) autoantibodies from Peking Union Medical College Hospital between January 2000 and July 2016 were retrospectively studied. The PubMed database was also searched for literature to collect published cases.

Results

In our center, nine patients were diagnosed as sPAP with a median age of 37 years. Hematological disorders, including myelodysplastic syndrome (MDS), chronic myelogenous leukemia (CML), and pulmonary tuberculosis (TB) infection were the underlying diseases. Cases secondary to MDS had very poor prognosis as all of them survived less than 2 years after their diagnosis, while those secondary to TB had favorable prognosis. Only 33.3% of cases showed interlobular septal thickening in our sPAP group. Through literature review, 164 sPAP cases were collected. The age at diagnosis was 45.0 ± 14.8 years old and the gender radio was 1.20:1 (M:F). 61.9% of cases were diagnosed by bronchoscopy. MDS and CML were common underlying diseases in 34.1% and 15.2% of patients, respectively. Patients with sPAP secondary to hematological diseases had a short survival time and half of them died within 14.95 months after diagnosis.

Conclusions

MDS and TB infection were the most frequent underlying causes of sPAP in this single-center research in China, with cases secondary to MDS having a poor survival rate. sPAP was more likely to be secondary to hematological disorders, especially MDS and CML and had a fairly poor prognosis in published cases. sPAP should be suspected in PAP patients whose CT scan presents only ground-glass opacities without interlobular septal thickening.

Electronic supplementary material

The online version of this article (10.1186/s12890-018-0590-z) contains supplementary material, which is available to authorized users.

Clinical significance of cigarette smoking and dust exposure in pulmonary alveolar proteinosis: a Korean national survey

BACKGROUND

This study aimed to investigate clinical characteristics of Korean PAP patients and to examine the potential risk factors of PAP.

METHODS

We retrospectively reviewed medical records of 78 Korean PAP patients diagnosed between 1993 and 2014. Patients were classified into two groups according to the presence/absence of treatment (lavage). Clinical and laboratory features were compared between the two groups.

RESULTS

Of the total 78 PAP patients, 60% were male and median age at diagnosis was 47.5 years. Fifty three percent were ever smokers (median 22 pack-years) and 48% had a history of dust exposure (metal 26.5%, stone or sand 20.6%, chemical or paint 17.7%, farming dust 14.7%, diesel 14.7%, textile 2.9%, and wood 2.9%). A history of cigarette smoking or dust exposure was present in 70.5% of the total PAP patients, with 23% having both of them. Patients who underwent lavage (n = 38) presented symptoms more frequently (38/38 [100%] vs. 24/40 [60%], P < 0.001) and had significantly lower PaO₂ and DL_CO with higher D(A-a)O₂ at the onset of disease than those without lavage (n = 40) (P = 0.006, P < 0.001, and P = 0.036, respectively). Correspondingly, the distribution of disease severity score (DSS) differed significantly between the two groups (P = 0.001). Based on these, when the total patients were categorized according to DSS (low DSS [DSS 1-2] vs. high DSS [DSS 3-5]), smoking status differed significantly between the two groups with the proportion of current smokers significantly higher in the high DSS group (11/22 [50%] vs. 7/39 [17.9%], P = 0.008). Furthermore, current smokers had meaningfully higher DSS and serum CEA levels than non-current smokers (P = 0.011 and P = 0.031), whereas no difference was found between smokers and non-smokers. Regarding type of exposed dust, farming dust was significantly associated with more severe form of PAP (P = 0.004).

CONCLUSION

A considerable proportion of PAP patients had a history of cigarette smoking and/or dust exposure, suggestive of their possible roles in the development of PAP. Active cigarette smoking at the onset of PAP is associated with the severity of PAP.

GM-CSF Autoantibody-positive Pulmonary Alveolar Proteinosis with Simultaneous Myeloproliferative Neoplasm

Pulmonary alveolar proteinosis (PAP) is classified as autoimmune, secondary, or genetic. We herein describe a 69-year-old man with autoimmune PAP, simultaneously diagnosed with myeloproliferative neoplasm (MPN). Two years after the diagnosis, the MPN progressed to acute myeloid leukemia, and the patient died from an alveolar hemorrhage during remission induction chemotherapy. Throughout the clinical course, no progression of PAP was observed, despite the progression to leukemia. There are few reports of autoimmune PAP with hematological malignancy, and this case demonstrated that an evaluation for GM-CSF autoantibodies is important for distinguishing the autoimmune and secondary forms of PAP, even if the patient has hematological malignancy.

Update on Diffuse Lung Disease in Children

Diffuse lung diseases in children, also called children's interstitial lung disease, are a diverse group of rare disorders that cause disturbances of gas exchange in the lungs. Although individually rare, there are many different forms of diffuse lung disease in children, and collectively these disorders are associated with significant morbidity and mortality, as well as health-care resource utilization. Over the past several years, there have been many significant advances in the field, including genetic discoveries and the development of clinical practice guidelines. This review summarizes recent advances in the understanding, diagnosis, and treatment of diffuse lung diseases in children.

Pneumonia After Hematopoietic Stem Cell Transplantation

Pneumonia is the main cause of morbidity and mortality after hematopoietic stem cell transplantation. Two thirds of pneumonias observed after both autologous and allogeneic stem cell transplantations are of infectious origin, and coinfections are frequent. One third is due to noninfectious process, such as alveolar hemorrhage, alveolar proteinosis, or alloimmune pulmonary complications such as bronchiolitis obliterans or idiopathic interstitial pneumonitis. Most of these noninfectious complications may require treatment with corticosteroids which may be deleterious in infection. On the other hand, these complications either mimic or may be complicated with infections. Therefore, a precise diagnosis of pneumonia is of crucial importance to decide of the optimal treatment. CT scan is the best procedure for imaging of the lung. Although several indirect biomarkers, such as serum or plasma galactomannan or (1-3) β(beta)-G-glucan, can help in the etiological diagnosis, only direct invasive investigations provide the best chance to identify the cause(s) of pneumonia. Bronchoalveolar lavage (BAL) under fiberoptic bronchoscopy is the procedure of choice to identify the cause of pulmonary infection. It is safe and reproducible, and its diagnostic yield is around 50 % if the BAL fluid is processed at the laboratory according to a prespecified protocol established between the transplanter, the infectious diseases’ specialist, the pneumologist, and the laboratory, allowing the identification of the most likely hypotheses. Transbronchial biopsy does not provide significant additional information to BAL in most cases and more often complicates with bleeding and pneumothorax. In case of a noncontributory BAL, the decision to proceed to a second BAL, a transthoracic biopsy, or a surgical biopsy should be cautiously weighted in a multidisciplinary approach in regard to the benefits and risks of invasive procedures versus empirical treatment.

GATA2 deficiency in children and adults with severe pulmonary alveolar proteinosis and hematologic disorders

BACKGROUND

The majority of cases with severe pulmonary alveolar proteinosis (PAP) are caused by auto-antibodies against GM-CSF. A multitude of genetic and exogenous causes are responsible for few other cases. Goal of this study was to determine the prevalence of GATA2 deficiency in children and adults with PAP and hematologic disorders.

METHODS

Of 21 patients with GM-CSF-autoantibody negative PAP, 13 had no other organ involvement and 8 had some form of hematologic disorder. The latter were sequenced for GATA2.

RESULTS

Age at start of PAP ranged from 0.3 to 64 years, 4 patients were children. In half of the subjects GATA2-sequence variations were found, two of which were considered disease causing. Those two patients had the typical phenotype of GATA2 deficiency, one of whom additionally showed a previously undescribed feature - a cholesterol pneumonia. Hematologic disorders included chronic myeloic leukemia, juvenile myelo-monocytic leukemia, lymphoblastic leukemia, sideroblastic anemia and two cases of myelodysplastic syndrome (MDS). A 4 year old child with MDS and DiGeorge Syndrome Type 2 was rescued with repetitive whole lung lavages and her PAP was cured with heterologous stem cell transplant.

CONCLUSIONS

In children and adults with severe GM-CSF negative PAP a close cooperation between pneumologists and hemato-oncologists is needed to diagnose the underlying diseases, some of which are caused by mutations of transcription factor GATA2. Treatment with whole lung lavages as well as stem cell transplant may be successful.

Treatment of Adult Primary Alveolar Proteinosis

Pulmonary alveolar proteinosis (PAP) is a rare disease characterized by the accumulation of surfactant-like lipoproteinaceous material in the distal air spaces and terminal bronchi, which may lead to impaired gas exchange. This accumulation of surfactant is due to decreased clearance by the alveolar macrophages. Its primary, most common form, is currently considered an autoimmune disease. Better knowledge of the causes of PAP have led to the emergence of alternatives to whole lung lavage, although this is still considered the treatment of choice. Most studies are case series, often with limited patient numbers, so the level of evidence is low. Since the severity of presentation and clinical course are variable, not all patients will require treatment. Due to the low level of evidence, some objective criteria based on expert opinion have been arbitrarily proposed in an attempt to define in which patients it is best to initiate treatment.