Fine structural changes in idiopathic pulmonary haemosiderosis

[Pathogenesis of pulmonary fibrosis]

A literature review reflects data on the mechanisms of pulmonary fibrosis after a novel coronavirus infection associated with the SARS-COV2 virus. Factors contributing to post-COVID lung remodeling are considered. According to the literature, in the mechanism of pulmonary fibrosis, during the course of the disease and during the recovery period, both direct viral damage and death of alveolocytes and endothelium, the development of a systemic inflammatory reaction due to inadequate secretion of cytokines, especially type 2, which are activators of the proliferation of fibroblasts and myofibroblasts, are important. The influence of angiogenesis disorders and vascular dysfunction on pneumofibrosis was noted. Attention is also paid to the relationship between the development of pulmonary fibrosis and abnormal activation of the renin-angiotensin-aldosterone system. In combination with the action of many factors, especially germinal ones, an imbalance between profibrogenic and antifibrogenic action develops and fibrosis occurs.

Updates in idiopathic pulmonary hemosiderosis in 2022: A state of the art review

This manuscript reports the recent advances in idiopathic pulmonary hemosiderosis (IPH), a rare cause of diffuse alveolar hemorrhage in children and adults. This narrative review of the literature summarizes different aspects of IPH, including proposed pathogenesis, patient demographics, clinical and radiological characteristics, treatment, and prognosis. Additionally, the association between Celiac Disease (CD) and IPH is carefully evaluated. IPH is a frequently misdiagnosed disease. The delay in the diagnosis of IPH is often significant but fortunately, appears to have decreased in recent years. IPH in adults and children have distinct demographic preferences. The autoantibodies are common in IPH but with a definite difference between the adult and pediatric populations. The definitive diagnosis of IPH requires lung biopsy and careful exclusion of all competing diagnoses, even with lung biopsy showing bland pulmonary hemorrhage. The presence of nonspecific inflammatory cells or lymphoid aggregates may suggest a secondary immunologic phenomenon and needs careful evaluation and follow-up. A substantial number of patients suffer from coexisting CD, also known as Lane-Hamilton syndrome (LHS), and all patients with IPH need to be evaluated for LHS by serology. Although strict gluten free diet can manage the majority of patients with LHS, other patients generally require immunosuppressive therapy. The corticosteroids are the backbone of IPH therapy. Recently utilized experimental treatment options include mesenchymal stem cell transplant, liposteroid and bronchial artery embolization. The immunosuppression should be adjusted to achieve optimal disease control. Patients may progress to end-stage lung disease despite all measures, and lung transplantation may be the only viable option.

A 49-year-old man with ischemic cardiomyopathy and persistent hemoptysis for eighteen months

Idiopathic pulmonary hemosiderosis (IPH) is a rare cause of recurrent episodes of diffuse alveolar hemorrhage (DAH). IPH commonly manifests with hemoptysis, radiologic chest infiltrates and anemia. The etiology of IPH is unknown, but an immunologic mechanism is widely speculated. The definitive diagnosis of IPH requires a thorough exclusion of other causes of DAH, such as infections, inflammation, malignancy, cardiac diseases, drug and toxin exposure, and medications. Due to the rarity of the disease, a diagnosis is often delayed by years. We present the case of a 49-year-old man with ischemic cardiomyopathy who presented with hemoptysis for eighteen months. Serologic workup was negative for vasculitides and autoimmune diseases. Bronchoscopy revealed DAH. A surgical lung biopsy showed 'bland pulmonary hemorrhage.' A right heart catheterization ruled out cardiac causes of DAH. The patient was diagnosed with IPH and started on systemic corticosteroids with rapid improvement of hemoptysis.

Proposed Pathogenesis of Diffuse Alveolar Hemorrhage in Idiopathic Pulmonary Hemosiderosis

Idiopathic pulmonary hemosiderosis (IPH) is a rare disease that causes diffuse alveolar hemorrhage (DAH). The latest data suggests an immunologic origin of IPH, and a new name, immune mediated pulmonary hemosiderosis (ImPH), has been proposed. However, the exact immunologic mechanism has remained elusive for nearly eight decades despite extensive research, including detailed histopathologic analysis. Although several hypotheses have been proposed to describe the pathobiology of IPH, none of them explain the clinical and histopathologic findings conclusively. In this manuscript, we have presented a new hypothesis for the pathogenesis of DAH in IPH. We hypothesize that DAH in IPH is not immunocomplex mediated but due to histamine, eosinophilic cationic protein (ECP), and possibly vascular endothelial growth factor (VEGF). These bioactive proteins induce endothelial and alveolar epithelial damage, leading to the peri-capillary and intraalveolar escape of RBCs. The deformability of the RBC likely also plays a role. The supranormal secretion of histamine, ECP and VEGF occurs in genetically predisposed individuals with an aberrant immunologic response. The histamine is released from the basophils and possibly the mast cells in response to cytokines secreted by activated lymphocytes. The lymphocyte activation occurs after exposure to a known (gluten) or unknown antigen. The same lymphocyte-derived cytokines also induce eosinophilic degranulation of ECP and VEGF in the pulmonary circulation. We believe that our hypothesis unifies the observed clinical variabilities and histopathologic findings in IPH, and we hope that would promote future research in the field of IPH.

Comparative Analysis of Adult Patients With Idiopathic Pulmonary Hemosiderosis and Lane-Hamilton Syndrome: A Systematic Review of the Literature in the Period 1971-2022

Idiopathic pulmonary hemosiderosis (IPH) causes diffuse alveolar hemorrhage (DAH) by a yet unknown mechanism. The coexistence of IPH and celiac disease (CD), also known as Lane-Hamilton syndrome (LHS), has been reported in both pediatric and adult patients. The objective of this study was to compare demographics, clinical and radiologic findings, treatment, and outcomes between adult patients with IPH and LHS.

This is a systematic review of the literature. Multiple databases were searched using appropriate formulas to identify relevant articles. A total of 60 studies reporting 65 patients were included in the review. Forty-nine of these patients had IPH and 16 had LHS. The prevalence of anti-CD antibodies among tested patients was 13/22 (59%). The symptom onset and diagnosis of IPH occurred earlier in patients with LHS. The median delay in diagnosis was the same between the two groups (52 weeks). The classic triad was more likely to be present in patients with LHS. Only 20% of patients in the LHS cohort had any significant gastrointestinal (GI) symptoms at the time of IPH diagnosis. A gluten-free diet alone was effective in the majority of patients. Fewer patients in the LHS cohort received systemic corticosteroid than the IPH cohort. The recurrence and mortality in patients with LHS appear to be less than in the IPH cohort. The prevalence of CD is 25% in adult patients with IPH. Patients with LHS may have a milder course than patients without CD. Serologic testing for CD should be performed in all patients diagnosed with IPH.

GSPE Protects against Bleomycin-Induced Pulmonary Fibrosis in Mice via Ameliorating Epithelial Apoptosis through Inhibition of Oxidative Stress

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive interstitial lung disease of unknown cause which leads to alveolar epithelial cell apoptosis followed by basement membrane disruption and accumulation of extracellular matrix, destroying the lung architecture. Oxidative stress is involved in the development of alveolar injury, inflammation, and fibrosis. Oxidative stress-mediated alveolar epithelial cell (AEC) apoptosis is suggested to be a key process in the pathogenesis of IPF. Therefore, the present study investigated whether grape seed proanthocyanidin extract (GSPE) could inhibit the development of pulmonary fibrosis via ameliorating epithelial apoptosis through the inhibition of oxidative stress. We found that GSPE significantly ameliorated the histological changes and the level of collagen deposition in bleomycin (BLM)-induced lungs. Moreover, GSPE attenuated lung inflammation by reducing the total number of cells in bronchoalveolar lavage (BAL) fluid and decreasing the expression of IL-6. We observed that the levels of H2O2 leading to oxidative stress were increased following BLM instillation, which significantly decreased with GSPE treatment both in vivo and in vitro. These findings showed that GSPE attenuated BLM-induced epithelial apoptosis in the mouse lung and A549 alveolar epithelial cell through the inhibition of oxidative stress. Furthermore, GSPE could attenuate mitochondrial-associated cell apoptosis via decreasing the Bax/Bcl-2 ratio. The present study demonstrates that GSPE could ameliorate bleomycin-induced pulmonary fibrosis in mice via inhibition of epithelial apoptosis through the inhibition of oxidative stress.

Risk factors for recurrent pulmonary exacerbation in idiopathic pulmonary hemosiderosis

OBJECTIVES

To evaluate the risk factors of recurrent pulmonary exacerbation and poor prognosis in children with idiopathic pulmonary hemosiderosis (IPH).

METHODS

In this multicenter study, 54 patients with a diagnosis of IPH were included. Medical records were retrospectively reviewed from three tertiary care hospitals between 1979 and 2019. Also, current information and the long-term progress of patients was determined by contacting the families by telephone.

RESULTS

A total of 54 children were included. The median age of onset of symptoms was 4.5 years (3 months to 15.8 years). The median time from onset to diagnosis was 0.9 years (0.25 months to 12 years). The mean number of recurrent episodes per child in the recurrence-positive group was 3.55 (1-15). Univariate analysis demonstrated that patients presenting with hypoxia or requiring transfusion at the time of presentation had significantly more recurrence episodes (p = .002). Multivariate analysis showed that the presence of hypoxia at the time of initial presentation was a significant independent predictor of recurrent episodes (p = .027). The median follow-up was 3.3 years (0.75 months to 27 years). There was a significant relationship between the presence of hypoxia, transfusion history, antinuclear antibody positivity, and elevated transaminases at the time of initial evaluation and treatment response.

CONCLUSIONS

The present study provides substantial information regarding factors that may affect recurrent exacerbations and prognosis in children with IPH. Demonstrating hypoxia as an independent risk factor in recurrence episodes could guide physicians in the planning of treatment strategies.

Idiopathic pulmonary hemosiderosis: A state of the art review

Idiopathic pulmonary hemosiderosis (IPH) is an uncommon cause of diffuse alveolar hemorrhage (DAH). Patients with IPH usually present with hemoptysis, and the diagnosis is often delayed by years. Patients often present with intermittent episodes of hemoptysis interspersed between periods of relative normalcy. However, massive hemorrhage resulting in acute respiratory failure and non-remitting hemoptysis have also been described. The classic triad includes hemoptysis, radiologic lung infiltrate, and iron deficiency anemia. Several hypotheses regarding the pathogenesis of IPH have been proposed. These risk factors include an autoimmune, allergic or genetic predisposition, and possible environmental exposure. Since IPH appears to be responsive to corticosteroids, the autoimmune hypothesis is considered to play a crucial role. A diagnosis of IPH requires exclusion of other etiologies of DAH, including infection, medications, toxic inhalation, vasculitis, and anti-glomerular basement membrane disease, among others. Histologically, IPH is characterized by the presence of hemosiderin-laden macrophages in the alveolar space without any evidence of vasculitis or immunocomplex deposition. Corticosteroid therapy represents the primary modality of treatment. Other immunosuppressive medications have also been used with varying success, especially in the setting of steroid-refractory disease. The prognosis of IPH in adults is somewhat better compared to the pediatric population. The severity of the initial presentation does not predict future outcomes. Which risk factors and patient characteristics are associated with a poor outcome are also unknown. More research is necessary to elucidate the pathophysiology and appropriate treatment.

Idiopathic Pulmonary Hemosiderosis as a Mimic of Pulmonary Vasculitis: A Case Report and Review of the Literature

PURPOSE OF REVIEW

Idiopathic pulmonary hemosiderosis (IPH) is one of the rarest and least understood causes of pulmonary hemorrhage in children. Illustrated by a complex case presentation, we discuss the clinical manifestations, diagnosis, pathology, proposed etiologies, and treatment of this rare disease. We also compare IPH with anti-glomerular basement membrane antibody syndrome (anti-GBM disease), another rare causes of pediatric pulmonary hemorrhage.

RECENT FINDINGS

Recent retrospective studies regarding IPH along with advanced immunotherapy have led to an improved understanding of how to best treat this condition, potential associations, and improved prognosis. Pathogenesis remains unknown, but several reports have suggested involvement of the alveolar capillary basement membrane. IPH is a poorly understood disease of unknown etiology that is a diagnosis of exclusion. Our patient was diagnosed with IPH after an exhaustive workup, including lung biopsy, into other immune-mediated causes of disease. While the pathogenesis of this rare disease remains elusive, our patient's immunofluorescent staining along the alveolar basement membrane without evidence of circulating antibody to type IV collagen raises the question of an immune-mediated pathogenesis of the disease with involvement of the alveolar basement membrane.

Clinical characteristics and prognosis of idiopathic pulmonary hemosiderosis in pediatric patients

OBJECTIVE

This study aimed to analyze the clinical characteristics and prognosis of pediatric idiopathic pulmonary hemosiderosis (IPH).

METHODS

Pediatric IPH cases that were diagnosed at West China Second University Hospital, Sichuan University between 1996 and 2017 were reviewed. Follow-up data from 34 patients were collected.

RESULTS

A total of 107 patients were included (42 boys and 65 girls). The median age was 6 years at diagnosis. The main manifestations of the patients were as follows: anemia (n = 100, 93.45%), cough (n = 68, 63.55%), hemoptysis (n = 61, 57%), fever (n = 23, 21.5%), and dyspnea (n = 23, 21.5%). There were relatively few pulmonary signs. The positive rates of hemosiderin-laden macrophages in sputum, gastric lavage fluid, and bronchoalveolar lavage fluid were 91.66%, 98.21%, and 100%, respectively. Seventy-nine patients were misdiagnosed. A total of 105 patients were initially treated with glucocorticoids, among whom 102 survived and three died. Among the followed up patients, two died and 32 survived, among whom 10 presented with recurrent episodes.

CONCLUSIONS

The classic triad of pediatric IPH is not always present. The rates of misdiagnosis and recurrence of IPH are high. Early recognition and adequate immunosuppressive therapy are imperative for improving prognosis of IPH.

Idiopathic pulmonary hemosiderosis in adults: a case report and review of the literature

Idiopathic pulmonary hemosiderosis is a very rare condition rarely affecting adults and causing recurrent episodes of diffuse alveolar haemorrhage that may lead to lung fibrosis. Due to lack of pathognomonic findings, IPH diagnosis is established upon exclusion of all other possible causes of DAH in combination with specific pathologic findings revealing bland alveolar haemorrhage with absence of vasculitis and/or accumulation of immune complexes within lung parenchyma. Here we describe a rare case of idiopathic pulmonary hemosiderosis in an otherwise healthy 27-year-old Greek male patient with relapsing episodes of fever accompanied by general fatigue and discomfort. He was at this time point a light smoker and had been hospitalised once in the past for similar symptoms. His iron deficiency anemia coupled with chest high-resolution computed tomography and bronchoalveolar lavage revealed findings compatible with diffuse alveolar hemorrhage. After excluding all other sources of bleeding through extensive gastrointestinal workup and thorough immunologic profile, video-assisted thoracic lung biopsy was performed and the diagnosis of Idiopathic Pulmonary Hemosiderosis was established. Patient was treated with high doses of oral corticosteroids, leading to clinical response. We highlight the need for vigilance by the respiratory physician for the presence of DAH, a challenging, acute condition requiring early recognition along with identification of the underlying syndrome and appropriate treatment to achieve optimal results.

Rapidly progressive pulmonary fibrosis following the onset of diffuse alveolar hemorrhage in Sjögren's syndrome: an autopsy case report

We report an autopsy case of a patient with Sjögren's syndrome (SjS) who presented with rapid progressive pulmonary fibrosis following the onset of diffuse alveolar hemorrhage (DAH) without cryoglobulinemia. Despite early and aggressive immunosuppressive therapy, pulmonary fibrosis progressed and the patient succumbed to his illness. An autopsy was performed and revealed DAH and interstitial pneumonia with a fibrotic nonspecific interstitial pneumonia pattern. We could not find any previously-reported underlying causes of DAH. The findings from this case suggest that DAH can occur as a pulmonary manifestation of SjS as well as other connective tissue diseases or vasculitis.

Interstitial inflammatory lesions of the pulmonary allograft: a retrospective analysis of 2697 transbronchial biopsies

BACKGROUND

Parenchymal and bronchial inflammatory and fibrotic lesions other than acute cellular rejection (ACR) and lymphocytic bronchiolitis are prevalent; however, the context in which they appear is unknown, and often no specific treatment is instigated.

OBJECTIVES

To describe the prevalence, incidence and possible associations between commonly identified inflammatory and fibrotic lesions in the pulmonary allograft.

METHODS

Retrospective chart review of all transbronchial biopsies performed within the first 2 years of 299 lung-transplanted patients in the period 1996 to 2006.

RESULTS

A total of 2697 biopsies were evaluated corresponding to a mean of 6+/-2 (median 8) completed schedules per patient. Diffuse alveolar damage (DAD) was the second most common histological finding within the first 2 weeks after transplantation. The peak prevalence of bronchiolitis obliterans organizing pneumonia (BOOP) and interstitial pneumonitis occurred at 4 to 6 weeks, and 6 to 12 weeks, respectively. There was a steady increase in the cumulative proportion of patients with fibrosis and bronchiolitis obliterans, at each successive scheduled surveillance time point beyond 3 months posttransplantation. The strongest histological correlations were between ACR and lymphocytic bronchiolitis (OR 5.1, P<0.0001) or interstitial fibrosis (OR 3.2, P<0.0001). Patients with interstitial pneumonitis and pulmonary hemosiderosis were also more likely to demonstrate the finding of interstitial fibrosis (OR 3.0 and 3.7, P<0.0001, respectively). Acute cellular rejection was not associated with DAD, and patients with lymphocytic bronchiolitis were not more likely to demonstrate features of organizing pneumonia (DAD or BOOP).

CONCLUSIONS

Histologic findings of ACR, lymphocytic bronchiolitis, BOOP, and interstitial pneumonitis were directly associated with the development of interstitial fibrosis and bronchiolitis obliterans.

Acquired Nonneoplastic Neonatal and Pediatric Diseases

The lung biopsy is an established procedure to procure a pathologic diagnosis in a child with a suspected pneumonic process of undetermined etiology. Improvements in pediatric anesthesia and surgery have reduced the operative complications to a minimum. A biopsy can usually be taken through a small intercostal incision when localization is not especially important in a patient with diffuse changes (see Chapter 1). The alternative method for tissue sampling is the endoscopic transbronchial biopsy. There is less risk to the patient, but the specimen is smaller and crush artifacts from the instrument are more common.

Mechanisms of pulmonary fibrosis

Tissue injury evokes highly conserved, tightly regulated inflammatory responses and less well-understood host repair responses. Both inflammation and repair involve the recruitment, activation, apoptosis, and eventual clearance of key effector cells. In this review, we propose the concept of pulmonary fibrosis as a dysregulated repair process that is perpetually "turned on" even though classical inflammatory pathways may be dampened or "switched off." Significant regional heterogeneity, with varied histopathological patterns of inflammation and fibrosis, has been observed in individual patients with idiopathic pulmonary fibrosis. We discuss environmental factors and host response factors, such as genetic susceptibility and age, that may influence these varied manifestations. Better understanding of the mechanisms of lung repair, which include alveolar reepithelialization, myofibroblast differentiation/activation, and apoptosis, should offer more effective therapeutic options for progressive pulmonary fibrosis.

Increased lower respiratory tract iron concentrations in alkaloidal ("crack") cocaine users

STUDY OBJECTIVE

We hypothesized that the use of inhaled alkaloidal ("crack") cocaine could increase lung content of iron, either by inducing alveolar hemorrhage or by other mechanisms. Intrapulmonary accumulation of iron could promote chronic lung diseases in crack users. The goal of this study was to determine whether iron and ferritin content of alveolar macrophages or fluid recovered by BAL was increased in subjects using crack, compared with nonsmokers.

METHODS

BAL was performed in 31 volunteer subjects, including healthy nonsmokers (n = 7), subjects smoking crack alone (n = 7), as well as subjects smoking both crack and cigarettes (n = 7) or cigarettes alone (n = 10). Iron content of alveolar macrophages and BAL fluid was determined by a colorimetric method and ferritin content of alveolar macrophages, and BAL fluid was measured by a two-sided immunoradiometric method.

RESULTS

Alveolar macrophages recovered from crack users contained more iron than did alveolar macrophages from nonsmokers (25.4 +/- 2.9 nmol/10(6) vs 5.5 +/- 0.6 nmol/10(6) [mean +/- SE]; p < 0.01). There were similar increases in alveolar macrophage ferritin as well as BAL fluid iron and ferritin in crack users, compared with nonsmokers. BAL fluid ferritin concentrations in subjects smoking both crack and cigarettes were increased, compared with subjects smoking crack alone or cigarettes alone (p < 0.05).

CONCLUSIONS

Use of crack increases intrapulmonary concentrations of iron and ferritin. Effects of crack on extracellular ferritin concentrations may be additive with effects of cigarette smoking. Although the mechanism(s) causing pulmonary iron accumulation were not identified by this study, it may be a result of occult alveolar hemorrhage or increased vascular permeability. The increase in lung iron burden in habitual crack users could promote chronic lung diseases in these subjects.

Idiopathic pulmonary haemosiderosis. Epidemiology, pathogenic aspects and diagnosis

Idiopathic pulmonary haemosiderosis (IPH) is a rare clinical entity characterized by recurrent episodes of diffuse alveolar haemorrhage, often presenting with haemoptysis. Many patients have iron deficiency anaemia due to deposition of haemosiderin iron in the alveoli, and eventually develop moderate pulmonary fibrosis. Typically, intensive search for an aetiology ends up negative. There is no evidence of pulmonary vasculitis or capillaritis. The aetiology is obscure, but may be an immunological or toxic mechanism causing a defect in the basement membrane of the pulmonary capillary. IPH affects both children and adults. During an acute episode, a chest X-ray demonstrates bilateral, alveolar infiltrates. Sputum examination discloses haemosiderin-laden alveolar macrophages. Diagnosis is established by lung biopsy (fiber-optic or thoracoscopic), showing large numbers of haemosiderin-laden macrophages in the alveoli and without evidence of capillaritis or deposition of immunoglobulins. Corticosteroids and/or immunosuppressive drugs may be effective during an acute bleeding episode, and may in some patients improve symptoms and prognosis on the long-term, but the response to treatment displays great interindividual variation.

Environmental risk factors associated with pediatric idiopathic pulmonary hemorrhage and hemosiderosis in a Cleveland community

BACKGROUND

Unexplained pulmonary hemorrhage and hemosiderosis are rarely seen in infancy. A geographic cluster of 10 infants with this illness was identified in a large pediatric referral hospital in Cleveland, Ohio, during the period of January 1993 through December 1994. One infant died of severe respiratory failure.

METHODS

A case-control study was conducted. Three control infants were matched by age with each case infant. All study infants' guardians were interviewed. Questions were asked about child care practices and home conditions for the period before case infants' illnesses. All infants' records were reviewed, their homes were visited, and a structural and environmental survey was conducted.

RESULTS

All 10 case infants were black, and 9 were male, whereas 50.0% of control infants were male, and 83.3% were black. The case infants' mean age was 10.2 weeks (range, 6 weeks to 6 months). Matched analysis demonstrated that case infants' homes were more likely to have had water damage preceding the pulmonary hemorrhage event (odds ratio, 16.25; 95% confidence interval, 2.55 to infinity). Case infants were also more likely to have had close relatives with pulmonary hemorrhage (odds ratio, 33.14; 95% confidence interval, 5.10 to infinity). In addition, 50.0% of case infants experienced recurrent pulmonary hemorrhaging after returning to their homes.

CONCLUSION

The results of this investigation of a cluster of infants with massive, acute pulmonary hemorrhage and hemosiderosis suggest that the affected infants may have been exposed to contaminants in their homes. Epidemiologic clues, such as water damage in the case infants' homes, suggest that environmental risk factors may contribute to pulmonary hemorrhage.

Idiopathic pulmonary haemosiderosis: a form of microscopic polyarteritis?

Idiopathic pulmonary haemosiderosis remains a diagnosis of exclusion in patients who present with pulmonary alveolar haemorrhage. Systemic vasculitis developed in a patient with an eight year history of idiopathic pulmonary haemosiderosis. The diagnosis was confirmed by a rising titre of antineutrophil cytoplasmic antibodies directed against myeloperoxidase. Treatment with immunosuppressive agents resulted in complete resolution of symptoms and suppression of the antibodies. Measurement of antineutrophil cytoplasmic antibodies is recommended for all patients with pulmonary alveolar haemorrhage syndromes.