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.

Idiopathic Pulmonary Haemosiderosis: An Unusual Case Of Anaemia With Pulmonary Involvement.

Idiopathic pulmonary haemosiderosis is a rare disorder, with recurrent life-threatening alveolar haemorrhages and chronic lung parenchymal changes. It is associated with a triad of haemoptysis, iron deficiency anaemia, and diffuse pulmonary infiltrates. Although most cases are idiopathic, secondary haemosiderosis linked to known diseases has also been observed. Most of the cases remain undiagnosed because the disease is very low on the list of differentials. There is no specified age for the disease. The present study reports on an adolescent female patient who presented with microcytic anaemia and bilateral lung infiltrates to the National Institute of Child Health (NICH), Karachi, a tertiary care hospital. She was diagnosed with Idiopathic pulmonary haemosiderosis after ruling out other possibilities.

Hemosiderosis in chronic dialysis patients: Monitoring the response to deferasirox by quantitative hepatic magnetic resonance imaging.

INTRODUCTION: Hemosiderosis of chronic dialysis has always been a frequent phenomenon in dialysis; formerly related to blood transfusions before the advent of Erythropoiesis Stimulating Agents (ESA), it is currently in connection with the use of massive doses of injectable iron, to ensure the full therapeutic efficacy of ESA. Few studies have looked at the therapeutic aspect of iron chelators in the dialysis population. METHODS: We followed 31 dialysis patients treated for secondary hemosiderosis with deferasirox (DFX) at the dose 10 mg/kg/day, by hepatic MRI from September 2017 to September 2021, in order to evaluate the efficacy of iron chelators on the reduction of liver iron concentration (LIC). The diagnosis of hemosiderosis was carried for a value of the LIC > 50 µmol/g of dry liver. RESULTS: Chelation resulted in a significant reduction in liver iron burden as measured by liver MRI: (201.4 ± 179.9 vs. 122.6 ± 154.3 µmol/g liver) (p = 0.000) and in mean ferritin level: (2058.8 ± 2004.9 vs. 644.2 ± 456.6 ng/mL) (p = 0.002). A gain of 1.1 g/dL in mean hemoglobin level: (10.5 ± 1.6 vs. 11.6 ± 2.0 g/dL) (p = 0.006). A significant increase in mean albumin level: (43 ± 5.5 to 46.2 ± 6.1 g/L) (p = 0.04). The therapeutic response was clearly influenced by the cause of overload, longer in polytransfused patients (p = 0.023) and the degree of overload assessed by MRI (p = 0.003) and ferritin level (p = 0.04). CONCLUSION: DFX, prescribed at a dose of 10 mg/kg/day, resulted in a significant reduction in hepatic iron burden as measured by liver MRI and ferritin. The therapeutic response was clearly influenced by blood transfusions and the degree of iron overload.

Bronchoalveolar lavage hemosiderosis in lightly active or sedentary horses.

BACKGROUND: Hemosiderophages in bronchoalveolar lavage fluid (BALF) are commonly ascribed to exercise-induced pulmonary hemorrhage (EIPH). Little information exists regarding the presence of these cells in horses that perform light or no work and that are referred for respiratory problems. OBJECTIVES: Evaluate the presence of hemosiderophages in BALF of horses suspected of respiratory disease without history of or risk factors for EIPH and determine predictors of hemosiderophages in BALF in this population. METHODS: Observational retrospective cross-sectional study using STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) guidelines. Bronchoalveolar lavage fluid cytology reports of 353 horses evaluated for respiratory disease between 2012 and 2022 at the Cummings School for Veterinary Medicine were reviewed retrospectively. Horses with a history or likelihood of having performed past strenuous exercise were removed, and the remaining 91 horses were divided into hemosiderin-positive (HSD-POS) and hemosiderin-negative groups based on Perls' Prussian blue staining. Potential predictors for the presence of hemosiderophages in BALF (history, clinical evaluation, baseline lung function, airway reactivity, BALF cytology, and hemosiderin score) were compared between the 2 groups, using univariate and multivariate analyses. RESULTS: Horses with a diagnosis of severe equine asthma (sEA; odds ratio, 11.1; 95% confidence interval, 3.2-38.5; P < .001) were significantly more likely to be HSD-POS than horses with mild-to-moderate equine asthma. CONCLUSIONS AND CLINICAL IMPORTANCE: Hemosiderophages were found in the BALF cytology in a subset of horses that perform light or no work and presented for respiratory signs; these cells were found more frequently in horses with sEA. The link between hemosiderophages and sEA highlights previously unstudied pathology associated with this common disease.

Idiopathic pulmonary hemosiderosis and stroke secondary to protein C deficiency in a child with Down syndrome: a case report.

BACKGROUND: Patients with Down syndrome are at a higher risk of developing autoimmune disorders such as thyroiditis, diabetes, and celiac disease compared with the general population. Although some diseases are well known to be associated with Down syndrome, others such as idiopathic pulmonary hemosiderosis and ischemic stroke due to protein C deficiency remain rare. CASE PRESENTATION: We report a case of a 2.5-year-old Tunisian girl with Down syndrome and hypothyroiditis admitted with dyspnea, anemia, and hemiplegia. Chest X-ray showed diffuse alveolar infiltrates. Laboratory tests showed severe anemia with hemoglobin of 4.2 g/dl without hemolysis. A diagnosis of idiopathic pulmonary hemosiderosis was confirmed by bronchoalveolar lavage showing numerous hemosiderin-laden macrophages, with a Golde score of 285 confirming the diagnosis of pulmonary hemosiderosis. Concerning hemiplegia, computed tomography showed multiple cerebral hypodensities suggestive of cerebral stroke. The etiology of these lesions was related to protein C deficiency. CONCLUSION: Idiopathic pulmonary hemosiderosis remains a severe disease, which is rarely associated with Down syndrome. The management of this disease in Down syndrome patients is difficult, especially when associated with an ischemic stroke secondary to protein C deficiency.

Cerebellar Superficial Siderosis in Cerebral Amyloid Angiopathy on 1.5T T2*-Weighted Imaging.

BACKGROUND: Cerebellar superficial siderosis (SS) has been recently reported to be present in about 10% of both hereditary and sporadic cerebral amyloid angiopathy (CAA) on 3T MRI using primarily susceptibility-weighted imaging. OBJECTIVES: Our aim was to assess cerebellar SS in sporadic CAA patients using 1.5T T2*-weighted MRI and to evaluate possible underlying mechanisms. METHOD: We retrospectively screened MRI scans of sporadic probable CAA patients initially presenting with intracerebral hemorrhage-, acute subarachnoid hemorrhage- or cortical SS-related symptoms between September 2009 and January 2022 registered in our stroke database. Patients with familial CAA were excluded. On 1.5T T2*-weighted MRI, cerebellar SS (including kappa statistics for interobserver agreement) was assessed together with typical CAA hemorrhagic features and with the presence of supratentorial macrobleed and cortical SS adjacent to the tentorium cerebelli (TC) and TC hemosiderosis. RESULTS: We screened 151 patients and finally included 111 CAA patients (median age 77) with cerebellar SS observed in 6 (5%) patients. Cerebellar SS presence was associated with a higher number of supratentorial macrobleeds (median n = 3 vs. n = 1, p = 0.0012), presence of supratentorial macrobleed adjacent to the TC (p = 0.002), and TC hemosiderosis (p = 0.005). CONCLUSIONS: Cerebellar SS in CAA patients can be identified on 1.5T T2*-weighted imaging. Associated MRI characteristics suggest contamination from supratentorial macrobleeds.

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.

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.

Recurrence of idiopathic pulmonary hemosiderosis in adults with childhood onset: A case report and literature review.

We describe a rare case of a 20-year-old Japanese man with idiopathic pulmonary hemosiderosis (IPH) recurrence in adults with childhood onset (racIPH). IPH commonly occurs in children, and data regarding racIPH are lacking. A review of the literature showed that only five cases of racIPH have been reported (including the present case) and that racIPH shows features that are intermediate between childhood- and adult-onset IPH with respect to age and a lower frequency of smoking history. We also found that the degree of anemia was usually not severe, and a favorable response to corticosteroid therapy is expected in racIPH.

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.

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.

Cochlea implantation in patients with superficial hemosiderosis.

INTRODUCTION: Superficial hemosiderosis is a sub-form of hemosiderosis in which the deposits of hemosiderin in the central nervous system damage the nerve cells. This form of siderosis is caused by chronic cerebral hemorrhages, especially subarachnoid hemorrhages. The diversity of symptoms depends on the respective damage to the brain, but in most of the cases it shows up as incipient unilateral or bilateral hearing loss, ataxia and signs of pyramidal tracts. We are investigating the question of whether cochlear implantation is a treatment option for patients with superficial hemosiderosis and which strategy of diagnostic procedure has to be ruled out preoperatively. MATERIALS AND METHODS: In a tertiary hospital between 2009 and 2018, we examined (N = 5) patients with radiologically confirmed central hemosiderosis who suffered from profound hearing loss to deafness were treated with a cochlear implant (CI). We compared pre- and postoperative speech comprehension (Freiburg speech intelligibility test for monosyllables and HSM sentence test). RESULTS: Speech understanding improved on average by 20% (monosyllabic test in the Freiburg speech intelligibility test) and by 40% in noise (HSM sentence test) compared to preoperative speech understanding with optimized hearing aids. DISCUSSION: The results show that patients with superficial siderosis benefit from CI with better speech understanding. The results are below the average for all postlingual deaf CI patients. Superficial siderosis causes neural damages, which explains the reduced speech understanding based on central hearing loss. It is important to correctly weigh the patient's expectations preoperatively and to include neurologists within the therapy procedure.

Puzzling (IRIDA-Like and Hemolytic) Anemia in a Child With Idiopathic Pulmonary Hemosiderosis.

Before the diagnosis of idiopathic pulmonary hemosiderosis (IPH), unexplained or puzzling anemia may precede and delay in the diagnosis of pediatric IPH is common. A 5.8 years old female child initiated with iron-refractory iron deficiency anemia-like iron deficiency and hemolytic anemia and at 6.8 years of age IPH was materialized, when the patient showed the triad signs of IPH with hemosiderin-laden alveolar macrophages in gastric aspirate. Although time to the diagnosis was previously reported to be ranged from 16 to 30 months, in our case it took 12 months from the initial anemia to IPH diagnosis.

High-Grade Fetal Vascular Malperfusion Is Associated With Diffuse Chorionic Hemosiderosis.

INTRODUCTION: Diffuse chorionic hemosiderosis (DCH) is an abnormality of the placental membranes characterized by the deposition of iron pigment. It is usually secondary to recurrent venous bleeding in early pregnancy. In many papers, it is associated with pre-term delivery. Fetal vascular malperfusion (FVM) is an abnormality of the feto-placental circulation that may be seen at any stage of gestation, but most often in the third trimester. It may be graded as low grade (LGFVM) or high grade (HGFVM). No link has been identified in the placental literature between DCH and FVM, but we have noted the 2 co-existing in placentas submitted for analysis. This study explored a possible association of these 2 entities. METHODS: Laboratory records were searched for singleton cases coded as DCH based on diagnosis on H&E stain over a 6-year period. Of 4478 placentas reported, 66 cases were coded as DCH (1.5%). These were classified as showing HGFVM, LGFVM, or no FVM. Controls (n = 132) were gestational age-matched cases without DCH. Cord length, coiling, insertion, or other abnormalities were noted. Membranes were classified as normal or circumvallate. Results were analyzed using Graphpad. RESULTS: Gestation ranged between 16 and 41 weeks gestation. 14/66 (21%) cases of DCH showed HGFVM and 2/66 (3%) showed LGFVM. 16/132 (12%) controls showed HGFVM and 21/132 (15.9%) had LGFVM. Where FVM is present, high-grade FVM is significantly associated with DCH versus controls (P < .0031 Fischer's Test). DISCUSSION: HGFVM occurs significantly more often in placentas with DCH than in controls. Both FVM and DCH are associated with adverse perinatal outcomes, and a possible relationship between the 2 remains to be clarified.

Pulmonary Nocardia infection in a child with idiopathic pulmonary hemosiderosis.

BACKGROUND: Idiopathic pulmonary hemosiderosis (IPH) encompasses a rare and agnogenic group of diffuse alveolar capillary hemorrhagic diseases. Corticosteroid treatment is the globally preferred therapeutic strategy for IPH; however, it can cause immunodeficiency. Nocardia infection often occurs in immunocompromised patients and primarily involves the pleura and lungs. Herein, we describe a case of pediatric pulmonary Nocardia infection after the corticosteroid treatment of IPH. CASE PRESENTATION: A 7-year-old girl presented with chief complaints of pale complexion persisting for 1 year and a cough for 20 days. Abundant hemosiderin-laden macrophages were detected in the gastric juice, which supported the diagnosis of IPH. Uninterrupted doses of corticosteroids were administered during the last hospitalization. After nearly 2 months of corticosteroids therapy, the patient began to cough and produce a purulent sputum. Next-generation sequencing of the bronchoalveolar lavage fluid revealed Nocardia abscessus (N. abscessus) DNA. Linezolid was administered with good response, and the patient was discharged after 18 days of hospitalization. Her symptoms and pulmonary lesions had recovered, and the IPH appeared to be well-controlled with low dose of corticosteroids in follow-up. CONCLUSIONS: Nocardia infection should be considered in the differential diagnoses for IPH patients receiving corticosteroid therapy, especially in patients with poor response to conventional empirical antibiotic therapy. Next-generation sequencing of bronchoalveolar lavage fluid may be used to quickly identify the Nocardia. Sulfonamides or linezolid are effective for pediatric pulmonary Nocardia infection.

Autoimmune pulmonary alveolar proteinosis and idiopathic pulmonary haemosiderosis: a dual pathology.

Pulmonary alveolar proteinosis (PAP) is a rare pulmonary condition which leads to excessive accumulation of proteinaceous material within the alveoli. Idiopathic pulmonary haemosiderosis (IPH) is another orphan lung disease and results in recurrent alveolar haemorrhage. This case study describes a case of these two rare pathologies occurring together. A man in his 50s presented with a 6-week history of haemoptysis and worsening dyspnoea. A CT scan of the thorax showed multifocal, bilateral ground glass opacification with a wide differential diagnosis. Full autoantibody screen including myositis panel and coeliac screen were negative. Bronchoscopy with bronchoalveolar lavage and tissue from a transbronchial lung cryobiopsy were non-diagnostic. Tissue from a video-assisted thoracoscopic surgery biopsy confirmed a diagnosis of PAP with IPH as a second separate pathology. The association of IPH and PAP has not previously been described. We discuss these conditions and postulate how and if they may be related.

Renal hemosiderosis presenting with acute kidney Injury and macroscopic hematuria in Immunoglobulin A nephropathy: a case report.

BACKGROUND: Macroscopic hematuria-associated acute kidney injury (AKI) is a well-known complication of immunoglobulin A (IgA) nephropathy. In such cases, intratubular obstruction by red blood cell (RBC) casts and acute tubular necrosis are mainly observed pathologically. Herein, we report the case of a patient with IgA nephropathy presenting with AKI following an episode of macrohematuria. The patient presented with severe renal tubular hemosiderosis and acute tubular necrosis and without any obvious obstructive RBC casts. CASE PRESENTATION: A 68-year-old woman, who was diagnosed with IgA nephropathy on renal biopsy 6 years ago, was admitted to our hospital after an episode of macroscopic glomerular hematuria and AKI following upper respiratory tract infection. Renal biopsy showed mesangial proliferation of the glomeruli, including crescent formation in 17 % of the glomeruli, and acute tubular necrosis without obvious hemorrhage or obstructive RBC casts. The application of Perls' Prussian blue stain showed hemosiderin deposition in the renal proximal tubular cells. Immunofluorescence showed granular mesangial deposits of IgA and C3. Based on these findings, she was diagnosed with acute tubular necrosis with a concurrent IgA nephropathy flare-up. Moreover, direct tubular injury by heme and iron was considered to be the cause of AKI. She was treated with intravenous pulse methylprednisolone followed by oral prednisolone. Thereafter, the gross hematuria gradually faded, and her serum creatinine levels decreased. CONCLUSIONS: IgA nephropathy presenting with acute kidney injury accompanied by macrohematuria may cause renal hemosiderosis and acute tubular necrosis without obstructive RBC casts. Hemosiderosis may be a useful indicator for determining the pathophysiology of macroscopic hematuria-associated AKI. However, renal hemosiderosis may remain undiagnosed. Thus, Perls' Prussian blue iron staining should be more widely used in patients presenting with hematuria.