Diffuse alveolar haemorrhage associated with subsequent development of ANCA positivity and emphysema in three young adults

An Adult Case of Idiopathic Pulmonary Hemosiderosis Associated with Pulmonary Fibrosis and Emphysematous Change

A 48-year-old woman was admitted to our hospital with acute respiratory failure. Chest computed tomography showed ground-glass opacity and patchy emphysematous lesions in both lungs. Corticosteroid therapy was effective; however, the disease worsened with the tapering of corticosteroids. Bronchoalveolar lavage revealed hemosiderin-laden macrophages, and video-assisted thoracic surgery showed diffuse interstitial fibrosis with diffuse alveolar hemorrhage (DAH). There was no evidence of vasculitis nor autoimmune diseases. This patient was diagnosed with idiopathic pulmonary hemosiderosis (IPH) that progressed to end-stage pulmonary fibrosis despite treatment. Autopsy demonstrated DAH with pulmonary fibrosis and emphysematous change, suggesting IPH-related pulmonary lesions.

Panacinar emphysema complicating idiopathic pulmonary hemosiderosis: a case report

Idiopathic pulmonary hemosiderosis (IPH) is a rare entity with no known underlying etiology. It can be complicated by lung fibrosis. Emphysema is rarely reported as a consequence of IPH. We present a case of a 30-year-old female who presented with recurrent hemoptysis and shortness of breath. Radiographs revealed advanced emphysematous changes of the lower lobes. The diagnosis of IPH was established with an open lung biopsy. She was treated with systemic steroids, underwent bullectomy and was subsequently maintained on inhaled steroids.

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.

Rituximab in Idiopathic Pulmonary Hemosiderosis in Children: A Novel and Less Toxic Treatment Option

Idiopathic pulmonary hemosiderosis (IPH) is a rare, potentially life-threatening chronic disease. Steroids are the cornerstone of treatment, even though toxicity and side-effects are very common. Recently, rituximab (RTX) has been suggested as a treatment option, although evidence for its efficacy and long-term safety is lacking. We describe the disease course of two pediatric patients with IPH that were treated with RTX for over 4 years. Demographics, treatments, and clinical variables such as growth, infections, imaging follow-up by CT, and data from pulmonary function tests were retrospectively described. These are the first two cases described with a long-term follow-up of pediatric IPH patients treated with RTX. RTX was well-tolerated and prevented outbreaks of bleeding. In addition, RTX had a robust steroid-sparing effect resulting in the improvement of growth, pulmonary function, and CT abnormalities.

Assessment of type I interferon signatures in undifferentiated inflammatory diseases: A Japanese multicenter experience

Purpose

Upregulation of type I interferon (IFN) signaling has been increasingly detected in inflammatory diseases. Recently, upregulation of the IFN signature has been suggested as a potential biomarker of IFN-driven inflammatory diseases. Yet, it remains unclear to what extent type I IFN is involved in the pathogenesis of undifferentiated inflammatory diseases. This study aimed to quantify the type I IFN signature in clinically undiagnosed patients and assess clinical characteristics in those with a high IFN signature.

Methods

The type I IFN signature was measured in patients' whole blood cells. Clinical and biological data were collected retrospectively, and an intensive genetic analysis was performed in undiagnosed patients with a high IFN signature.

Results

A total of 117 samples from 94 patients with inflammatory diseases, including 37 undiagnosed cases, were analyzed. Increased IFN signaling was observed in 19 undiagnosed patients, with 10 exhibiting clinical features commonly found in type I interferonopathies. Skin manifestations, observed in eight patients, were macroscopically and histologically similar to those found in proteasome-associated autoinflammatory syndrome. Genetic analysis identified novel mutations in the PSMB8 gene of one patient, and rare variants of unknown significance in genes linked to type I IFN signaling in four patients. A JAK inhibitor effectively treated the patient with the PSMB8 mutations. Patients with clinically quiescent idiopathic pulmonary hemosiderosis and A20 haploinsufficiency showed enhanced IFN signaling.

Conclusions

Half of the patients examined in this study, with undifferentiated inflammatory diseases, clinically quiescent A20 haploinsufficiency, or idiopathic pulmonary hemosiderosis, had an elevated type I IFN signature.

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.

Adult patients with idiopathic pulmonary hemosiderosis: a comprehensive review of the literature

Idiopathic pulmonary hemosiderosis (IPH) is a rare disease without a known incidence or prevalence in adults. Our knowledge of this entity is limited as there is no prospective or retrospective study with a reasonable number of patients. The objective is to describe the demographics, clinical manifestations, diagnosis, treatment, and prognosis of adult patients with IPH. The Medline and Embase databases were searched from inception to 2021 with appropriate search formulas to identify relevant articles following strict inclusion and exclusion criteria. Statistical analyses were performed for the entire cohort and prespecified subgroups. A total of 84 patients were identified. The majority of patients were males 54/84 (64.3%). The median age was 27 years. The manifesting symptoms were present in the following frequencies: anemia 76/83 (91.6%), dyspnea 71/83 (85.5%), hemoptysis 70/84 (83.3%), cough 22/84 (26.2%), and chest pain 9/84 (10.7%). The classic triad was present in 61/84 (79%) patients. The mean hemoglobin during the initial presentation was 8.4 gm/dL. A total of 16/57 (19.5%) tested positive for autoantibodies. The median delay in the diagnosis of IPH was 1.02 years. Immunosuppressive therapy was prescribed in 49/79 (62%) patients, and recurrence occurred in more than half of the patients 36/66 (54.5%). A total of 63/79 (79.7%) patients were alive during the final follow-up. IPH is more common in young adults with a male predominance. A high index of suspicion is necessary to attain an early diagnosis and possibly reduce the short-term mortality of nearly 20% and long-term complications.

Association between idiopathic pulmonary hemosiderosis and celiac disease in pediatric patients: A scoping review of the literature over the past 50 years

INTRODUCTION

Idiopathic pulmonary hemosiderosis (IPH) is a rare cause of diffuse alveolar hemorrhage, the mechanism of which is currently unknown. Nearly one-third of pediatric patients with IPH test positive for Celiac disease (CD) serology. Several hypothetical mechanisms have been proposed to unify the coexistence of these two entities, also referred to as Lane-Hamilton syndrome (LHS).

METHOD

This manuscript is a scoping review of the medical literature. Medline, Embase, and PubMed Central databases were searched between 1971 and 2021 with appropriate search words to identify all cases of pediatric LHS.

RESULTS

A total of 20 manuscripts with 23 pediatric patients with LHS were identified. The mean age was 11 years, and 13/23 (56.5%) of the children were boys. Hemoptysis was present in 57% of patients during diagnosis. Bronchoscopy with bronchoalveolar lavage demonstrating hemosiderin laden macrophages was the primary mode of diagnostic confirmation. Only three patients underwent lung biopsy. Any significant GI symptom was reported in a minority of patients (22%). Iron deficiency anemia on presentation was described in 83% of children. The majority of patients were malnourished. Serology for CD was positive in all patients, as was the histopathologic analysis of the small bowel biopsy. No patients had any other autoantibody positivity. The introduction of gluten free diet (GFD) was associated with a positive response in 20/23 patients.

CONCLUSION

All pediatric patients with IPH should undergo screening for CD. Low serum ferritin in patients with IPH could be suggestive of coexisting CD. Strict GFD should be tried as the initial therapy.

The Spectrum of Autoantibodies in Adult Patients With Idiopathic Pulmonary Hemosiderosis: A Brief Review of the Literature

While autoimmune antibodies or autoantibodies have been reported sporadically in adult patients with idiopathic pulmonary hemosiderosis (IPH), their true prevalence is unknown. The question as to whether any difference exists between antibody-positive and negative patients has not been explored. The primary objective of this paper was to assess the spectrum of autoantibody testing and its positivity rate. The other objectives included a comparative analysis of demographics, symptom onset, clinical manifestations, and differences in clinical outcomes between antibody-positive (cohort A) and negative (cohort B) patients. To that end, we conducted a retrospective review of the relevant published literature. Multiple databases were searched to retrieve studies published between 1990 and 2022.

A total of 35 studies, involving 38 patients, were identified. Five of these patients had a positive autoantibody. Patients in cohort A were older and more likely to be male. The frequencies of testing for these antibodies were as follows: antineutrophil cytoplasmic antibody (ANCA): 37/38 (97.4%), antinuclear antibody (ANA): 31/38 (81.6%), and anti-glomerular basement membrane antibody (anti-GBM): 30/38 (78.9%); 5/38 (13.2%) patients tested positive for an autoantibody, and two of these patients were positive for ANA, two for antithyroid antibody, and one patient tested positive for ANCA, rheumatoid factor (RF), and granulocyte monocyte-colony stimulating factor (GM-CSF) antibody. There was no difference between the cohorts regarding their clinical presentations, recurrence risks, and survival.

The occurrence of autoantibodies is uncommon in adult IPH patients. This is in contrast with the pediatric IPH patient population, where the prevalence is much higher (26.4% vs. 13.2%), and the antibodies are more diverse. Unlike pediatric patients, adult patients with autoantibodies do not necessarily have worse outcomes.

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.

Prevalence of autoantibodies in pediatric patients with idiopathic pulmonary hemosiderosis: a scoping review of the literature in the period 1980-2021

Idiopathic pulmonary hemosiderosis (IPH) is a rare disease of unknown etiology. Due to the frequent findings of autoimmune antibodies - autoantibodies, immunologic causation of the diffuse alveolar hemorrhage in IPH has been proposed, to assess the prevalence/frequency and type of autoantibodies in pediatric patients with IPH. In addition, the patient demographics, diagnostic modalities used to diagnose IPH, treatment, and outcomes were also evaluated. Scoping review: The PubMed, Medline, and Embase databases were searched with appropriate MeSH terms to identify relevant papers consistent with the defined inclusion criteria. Thirteen observational studies comprising a total of 352 pediatric patients were included in this review. The majority of subjects were girls 217 out of 352 (61.6%). The mean and median ages of patients ranged from 3.1-6.5 years to 2.3-7 years, respectively. In the 10 studies that specified the number of patients in their cohorts with either at least one positive autoantibody or no antibody, the overall prevalence of autoantibodies was 76 out of 288 patients (26.4%). The prevalence of specific antibodies was as follows: ANA, 20.3%; ANCA, 17%; anti-dsDNA, 9.1%; RF, 12%; anti-SMA, 23.2%; and celiac antibodies, 25.9%. Cow's milk protein allergy was present in 16.2% of the children. The significance of an association between IPH and the presence of autoantibodies has not been clarified. The autoantibodies could be suggestive of an overall immune dysregulation rather than causation. However, limited evidence based on a single study suggests that the presence of ANA may be associated with a higher risk of recurrence and worse outcomes. Further research, including prospective studies, will be crucial to explore a possible genetic linkage between vasculitides, systemic rheumatologic diseases, and 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.

Differentiation of idiopathic pulmonary hemosiderosis from rheumatologic and autoimmune diseases causing diffuse alveolar hemorrhage: establishing a diagnostic approach

This narrative review provides an overview of diffuse alveolar hemorrhage (DAH) associated with rheumatologic and autoimmune diseases and their differentiation from idiopathic pulmonary hemosiderosis (IPH). Relevant immunologic diseases associated with DAH are discussed, and a diagnostic flowchart is proposed to establish a "definitive" diagnosis of IPH within the spectrum of DAH. IPH is a rare cause of recurrent DAH both in children and adults. In adults, a definitive diagnosis of IPH requires a lung biopsy and histopathologic examination demonstrating intraalveolar hemorrhage, hemosiderin-laden macrophages, and a variable degree of fibrosis in the absence of both capillaritis and cellular inflammation. The presence of small vessel vasculitis points towards immunologic, well-differentiated, or sometimes undifferentiated rheumatologic diseases. However, it is essential to recognize that many rheumatologic diseases may in the initial phase present with DAH without any evidence of capillaritis, thus mimicking IPH. Although not definitely established, it is likely that immunologic processes are involved in IPH, and we, therefore, suggest the consideration of a more suitable term for the disease, e.g., "Immune-mediated Pulmonary Hemosiderosis" to acknowledge the aberrancy in the immune parameters and a positive response to immunosuppressive therapy.

Liposteroid Therapy for Idiopathic Pulmonary Hemosiderosis: A Scoping Review of the Literature

Idiopathic pulmonary hemosiderosis (IPH) is a rare cause of diffuse alveolar hemorrhage (DAH). Glucocorticosteroids (CS) represent the first line therapy for IPH. Although most patients respond to CS, steroid refractoriness is seen in an appreciable minority of patients. This paper reviews and evaluates the efficacy and safety profile of liposomal dexamethasone 21-palmitate (liposteroid) for the treatment of IPH. Medline, Embase and Web of Science biomedical databases were searched between 1980 and 2020 to identify papers describing patients with IPH, who were treated with liposteroid. A total of five articles were identified. Four in the form of case reports and one as a case series. A total of 12 pediatric patients (5 boys, 7 girls) were identified, with a median age of 2.3 years (range 0.5-8.6). Liposteroid therapy in intravenous doses ranging 0.06-0.1 mg/kg body weight appeared to be effective for both remission induction therapy, and maintenance therapy. There was no mortality among patients treated with liposteroid, either in the acute phase or during follow-up. The majority of patients for whom long-term follow-up data were available, were cured or in disease remission. No acute adverse events were reported, and long-term side effects were minimal and tolerable. Liposteroid represents a potential alternative or supplement to conventional CS therapy, as it appears to be more efficacious and associated with fewer side effects. Larger prospective, controlled trials are necessary to be able to define more precisely the therapeutic role of liposteroid in IPH.

Idiopathic pulmonary hemosiderosis: a review of the treatments used during the past 30 years and future directions

This paper reviews the literature on the treatment modalities for idiopathic pulmonary hemosiderosis (IPH) used over the past 30 years, attempting to define treatment options that appear to be efficacious and safe, and in addition presents a treatment algorithm. IPH is an uncommon etiology of diffuse alveolar hemorrhage. IPH is a rare disease in adults and often associated with a significant temporal delay in diagnosis. Patients present with hemoptysis, radiographic chest abnormalities, and iron deficiency anemia. Although several pathogenetic hypotheses have been proposed, IPH appears to be an immunologic disease, possibly with a genetic component. Corticosteroid therapy represents the first line of treatment, including liposome-incorporated dexamethasone palmitate (liposteroid). Additional immunomodulatory/immunosuppressive medications have been used with varying success, especially in the setting of steroid-refractory disease. Cyclophosphamide, azathioprine, hydroxychloroquine, mycophenolate mofetil, and mesenchymal cell transplantation have been attempted to improve outcome and reduce side effects. Controlled studies are needed to assess the optimal combination of medications, which are effective to control the disease.

New therapeutic strategies in lung vasculitis

PURPOSE OF REVIEW

To summarize the latest publications and provide a practical overview of treatment strategies for lung vasculitis associated with antineutrophil cytoplasmic antibodies (ANCAs).

RECENT FINDINGS

In patients with severe ANCA-associated vasculitis, plasma exchange, as adjunctive therapy to standard treatment, is not associated with improved survival or reduced risk of end-stage kidney disease. A regimen with reduced dose of glucocorticoids is equally effective to induce remission as a standard regimen. In patients without organ or life-threatening disease, mycophenolate mofetil can be used in combination with oral glucocorticoid therapy to induce remission, however, with a higher risk of relapse than when using rituximab or cyclophosphamide. For maintenance of remission, a tailored regimen of rituximab infusion was equivalent to a fixed regimen, with fewer perfusions. Belimumab, a human IgG1(Equation is included in full-text article.)monoclonal antibody against B-lymphocyte stimulator, did not decrease the relapse rate when added to azathioprine and glucocorticoids. Avacopan, a complement C5a receptor inhibitor, was effective in replacing high-dose glucocorticoids in achieving complete remission of vasculitis.

SUMMARY

Significant advances have been made in the treatment strategy to both induce remission and maintain remission in patients with ANCA-associated vasculitis. The choice should take into consideration efficacy, cost-effectiveness, safety profile, ease of use, and possibility of individual tailoring of treatment.

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 Associated with Emphysematous Change in an Adult Who Underwent Lung Transplantation

Idiopathic pulmonary hemosiderosis is characterized by repeated alveolar hemorrhaging. We herein report a 52-year-old Japanese woman who had shortness of breath, diffuse small nodules, thin-walled cysts, and bronchiolectasis. A surgical lung biopsy revealed peribronchial hemosiderosis, centrilobular emphysema, and fragile elastic fibers of the alveolar septa and small vessels. She ultimately underwent living-donor lung transplantation five years after the first visit.

Diffuse alveolar hemorrhage with histopathologic manifestations of pulmonary capillaritis: Three case reports

BACKGROUND

Diffuse alveolar hemorrhage (DAH) is a multicause pulmonary capillary hemorrhage or pulmonary vascular small vessel injury (mainly capillaries, including arteries and veins), causing pulmonary microcirculation blood to accumulate in the alveolar space. DAH is classified by the histological absence or presence of pulmonary capillaritis (PC) and is rarely reported in the literature.

CASE SUMMARY

This is a report of three girls aged 6-11 years with DAH and PC. Two patients had decreased hemoglobin and one had increased erythrocyte sedimentation rate. High-resolution computed tomography showed bilateral diffuse pulmonary infiltrate, and diagnosis of PC was confirmed by lung biopsy. Immunofluorescence test in one case showed granular IgG and a small amount of granular IgA deposit on the alveolar walls, and was negative in the other two cases, describing isolated pauci-immune PC. Treatment was with glucocorticoid alone or combination with immunosuppressants, and the symptoms resolved in all patients.

CONCLUSION

PC is classified as isolated and immune-mediated PC associated with systemic disease. It can be controlled in most children with glucocorticoid alone or combined with immunosuppressants.