Imaging characteristics of hemophagocytic lymphohistiocytosis

Concept and Diagnostic Challenges of Renal-Limited Hemophagocytic Syndrome/Macrophage Activation Syndrome

Hemophagocytic syndrome/macrophage activation syndrome (HPS/MAS) is a serious clinical condition that frequently leads to multiple organ failure, including acute kidney injury (AKI). Although the pathogenesis of AKI is not yet fully understood, it is believed to result from uncontrolled activation of the immune system involving macrophages and cytotoxic lymphocytes. Renal histology in HPS/MAS often presents with characteristic foamy glomerular lesions (glomerular lipidosis) with massive macrophage infiltration, known as histiocytic glomerulopathy. In this review, we introduce the recently proposed concept of renal-limited HPS/MAS as a novel etiology of histiocytic glomerular lipidosis. Patients with renal-limited HPS/MAS often develop AKI but do not fulfill the diagnostic criteria for HPS/MAS because their systemic manifestations are less severe. Therefore, the diagnosis largely depends on characteristic histological findings, that is, diffuse and global glomerular accumulation of foamy macrophages and cytotoxic lymphocytes accompanied by the interaction of these cells as well as the exclusion of various differential diseases. Although there are no established therapeutic regimens, these patients receive various types of therapies, including high-dose glucocorticoids, immunosuppressants, or anti-interleukin-1 drug, and generally achieve favorable outcomes. We summarized the concept, diagnostic challenges, and recent topics of this disease entity and discussed treatment options based on our own experiences.

Hemophagocytic lymphohistiocytosis and histiocytic necrotizing lymphadenitis secondary to hemodialysis catheter-related bloodstream infection caused by Corynebacterium Striatum

BACKGROUND

We herein described the coexistence of hemophagocytic lymphohistiocytosis (HLH) and histiocytic necrotizing lymphadenitis, alternatively known as the Kikuchi disease (KD), secondary to hemodialysis catheter-related bloodstream infection (BSI) caused by Corynebacterium striatum.

CASE PRESENTATION

A patient on maintenance hemodialysis had developed persistent fever and Corynebacterium striatum was subsequently identified from the culture of both catheter tip and peripheral blood. During mitigation of the BSI, however, his fever was unabated and ensuing workup further found thrombocytopenia, hyperferritinemia, hypertriglyceridemia, low NK cell activity and a surge in serum CD25 levels. Moreover, biopsy of the bone marrow and lymph node detected histopathological evidence of hemophagocytosis and KD, respectively. Upon these abnormalities, the title-bound diagnosis was considered and the patient was eventually recovered from the treatment of dexamethasone instead of antibiotics. Consistently, aberrations in his serum CD25 levels and NK cell activity had subsided two months after discharge.

CONCLUSIONS

Arguably, this encounter offered a unique chance to unravel the principal pathogenic cascade in immunobiology that made the three entities one disease continuum. As such, our work may add new understandings of HLH and/or KD secondary to severe infections in general and excessive release of cytokines in particular among patients with kidney diseases. The resultant early diagnosis is crucial to initiate appropriate treatment and improve the survival of patients with these challenging and potentially life-threatening disorders.

Imaging Spectrum of Neurological Manifestations of Hemophagocytic Lymphohistiocytosis in Pediatrics: A Case Series

Hemophagocytic lymphohistiocytosis (HLH) is an uncommon condition, which can result either from a primary genetic abnormality affecting children or secondary to various conditions like malignancy or infection predominantly in adults. HLH is associated with immune dysregulation, resulting in an uncontrolled overproduction and infiltration of lymphocytes and histiocytes. The infiltration predominantly involves liver, spleen, lymph nodes, and central nervous system. Neuroimaging features on magnetic resonance imaging are highly nonspecific and variable. The most typical findings include periventricular white matter hyperintensities and diffuse atrophy. Ring or nodular enhancing or nonenhancing focal parenchymal lesions may be seen. Here, we present three pediatric cases of primary HLH with a wide spectrum of imaging findings involving cerebral and cerebellar cortex, white matter, deep gray matter, and brain stem. The findings in these patients range from small nonenhancing hemorrhagic lesions and enhancing small lesions to ill-defined mass with mass effect and midline shift. Lesions in deep gray matter including thalamus, basal ganglia, and also brain stem in HLH are rarely described in literature. Early diagnosis of HLH and timely management can improve the course of the disease.

Emerging Trends in Radionuclide Imaging of Infection and Inflammation in Pediatrics: Focus on FDG PET/CT and Immune Reactivity

The most common indication for ¹⁸F-FDG PET/CT is tumor imaging, which may be performed for initial diagnosis, staging, therapeutic response monitoring, surveillance, or suspected recurrence. In the routine practice of pediatric nuclear medicine, most infectious, inflammatory, and autoimmune processes that are detected on ¹⁸F-FDG PET/CT imaging - except for imaging in fever or inflammation of unknown origin - are coincidental and not the main indication for image acquisition. However, interpreting these "coincidental" findings is of utmost importance to avoid erroneously attributing these findings to a neoplastic process. We review the recent literature on fever of unknown origin as well as inflammation of unknown origin in pediatrics and then focus on the ¹⁸F FDG PET/CT imaging findings seen in two specific entities with increased immune reactivity: hemophagocytic lymphohistiocytosis syndrome and the immune-related adverse events associated with checkpoint inhibitors. We will subsequently close with two sections highlighting related topics and relevant references for further reading.

Acute necrotizing encephalopathy associated with lymphoma-associated hemophagocytic lymphohistiocytosis: A case report and literature review

Damage associated with lymphoma-associated hemophagocytic lymphohistiocytosis (LA-HLH) to the central nervous system (CNS) is not uncommon. However, the combination with brain damage resembling acute necrotizing encephalopathy (ANE) is rarely reported. Herein, we introduce the diagnosis and treatment of a case of ANE associated with LA-HLH in our hospital and review the relevant literature. After treatment, the child was discharged with only dysarthria and decreased sucking ability. The child is now discharged from the hospital for 6 months with regular follow-up. There were no disease recurrence signs. LA-HLH and ANE were related to cytokine storm. Therefore, early steroid application is essential for treating these diseases.

Renal involvement as a unique manifestation of hemophagocytic syndrome

Renal-limited hemophagocytic syndrome (HPS) is a rare clinical setting characterized by abnormal activation of the immune system. Fever associated with pancytopenia, hepatosplenomegaly with liver dysfunction, and hypofibrinogenemia are usually observed in HPS. From a histological level, the presence of non-malignant macrophages infiltrating bone marrow and organs represents the hallmark of this condition. Non-malignant macrophages are associated with phagocytizing activities involving other blood cells. While primary HPS is usually associated with inherited dysregulation of the immune system, secondary HPS usually occurs in the context of infection or is linked to a neoplastic process. Clinical presentation varies and can potentially lead to life-threatening settings. While renal involvement has frequently been reported, however, detailed descriptions of the kidney manifestations of HPS are lacking. More critically, the diagnosis of HPS is rarely supported by renal biopsy specimens. We report four rare cases of biopsy-proven renal-limited HPS in patients presenting with acute kidney injury (AKI). The available evidence on this topic is critically discussed in light of the possible emergence of an autonomous entity characterized by an isolated kidney involvement.

Brain Magnetic Resonance Imaging Findings of Pediatric Hemophagocytic Lymphohistiocytosis Could Be Diagnostic and Life-Saving

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is a rare and fatal disease and may also present with central nervous system findings at the beginning without specific diagnostic criteria. Brain magnetic resonance imaging (MRI) findings are diverse and can also be diagnostic. We aimed to emphasize the importance of brain MRI findings in the early diagnosis of this fatal disease.

METHODS

MRI findings, clinical presentations, treatment response, and prognosis of seven patients with HLH were described.

RESULTS

There were seven pediatric patients who were initially diagnosed with HLH with neurological findings without systemic signs of HLH: four as primary, two as secondary, and one as possible primary HLH. All patients had contrast-enhancing diffuse cerebellar and brainstem lesions; patchy periventricular and callosal cerebral lesions were observed. Thalamus involvement was found in three (42.8%), corpus callosum involvement in six (85.7%), and cervical spinal involvement in one (14.2%). Patients were followed up with these MRI findings, with prediagnoses of toxic, metabolic, infectious, vascular, and demyelinating diseases. Not all patients met the HLH diagnostic criteria due to incomplete systemic/laboratory findings; therefore, only two were immediately directed for hematopoietic stem cell therapy. Four died shortly after admission, one patient could not be followed up after HLH treatment, and two patients who fulfilled the HLH diagnostic criteria underwent hematopoietic stem cell transplantation and survived.

CONCLUSIONS

Brain MRI findings, especially in the presence of neurological findings, allow for early diagnosis, which can be life-saving. These common features in brain MRI findings should be evaluated with this suspicion and included in HLH diagnostic criteria.

Characteristics and prognostic value of pleural effusion in secondary hemophagocytic lymphohistiocytosis

The clinical features of patients with secondary hemophagocytic lymphohistiocytosis (sHLH) complicated with pleural effusion have rarely been evaluated. We retrospectively analyzed 203 patients newly diagnosed with sHLH from July 2015 to July 2019 according to the HLH-2004 protocol. Baseline characteristics, laboratory results, and imaging were reviewed. Pleural effusion was found in 58.6% of the studied sHLH population, and characteristic imaging findings were minimal volume and bilaterality. Patients with pleural effusion had lower PLT counts, HB levels and ALB levels as well as higher sCD25 levels than those without pleural effusion (all p values < 0.05). Multivariate analyses showed that lg(sCD25) and PLT ≤ 65 × 10⁹/L were significant risk factors for developing pleural effusion in sHLH. Regarding prognostic value, survival analysis showed a lower survival probability for patients with pleural effusion than for those without pleural effusion (median OS, 90 vs. 164 days, p = 0.028). In multivariate analysis, pleural effusion was an independent prognostic factor for overall survival (OS) (HR 2.68; 95% CI 1.18–6.11, p = 0.019). Pleural effusion is frequently found in patients with sHLH and is associated with greater inflammation and worse outcomes.

Cytomorphologic Features Found in Cerebrospinal Fluid Specimens of Hemophagocytic Lymphohistiocytosis Patients

OBJECTIVES

Central nervous system involvement is present in 70% of patients with hemophagocytic lymphohistiocytosis (CNS-HLH). CNS-HLH is defined by neurologic deficits, neuroimaging abnormalities, or positive cerebrospinal fluid (CSF) findings. The CSF cytomorphologic spectrum of CNS-HLH, however, has not been well investigated.

METHODS

A retrospective review was performed on 64 CSF specimens from pediatric and adult patients with HLH. Ten patients had clinicoradiologic evidence of CNS involvement.

RESULTS

We identified five CSF cytomorphologic patterns: (1) hemophagocytosis, (2) vacuolated macrophages without evidence of hemophagocytosis, (3) monocytes and/or nonvacuolated macrophages, (4) acellular specimens, and (5) bloody specimens. Patterns 1 and 2 were common in CNS-HLH and rare in patients without CNS involvement. The CSF cytomorphologic patterns did not correlate well with WBC counts or protein concentration.

CONCLUSIONS

Our study offers a comprehensive view of the cytomorphologic features seen in CSF specimens from patients with HLH.

Secondary Hemophagocytic Lymphohistiocytosis Complicated by a Cavitary Lung Lesion in a Kidney Transplant Recipient

Hemophagocytic lymphohistiocytosis (HLH) is an uncommon life-threatening condition caused by an uncontrolled immunological response. It can develop secondary to malignancies, infections, systemic diseases, and immunosuppression. Multiple risk factors may present in kidney transplant recipients; however, the cases of HLH in this population have been described sparsely. We report a case of a 39-year-old female kidney transplant recipient who presented to the hospital nearly 3.5 years after the transplantation with general malaise, recent history of weight loss, fevers, and persistent anemia. Laboratory tests showed pancytopenia, hyperferritinemia, hypertriglyceridemia, and increased activity of lactate dehydrogenase. A bone marrow aspiration revealed hemophagocytosis, which led to the diagnosis of HLH. Therapy consisting of high-dose steroids and plasma exchanges was administered, resulting in a significant improvement of blood count parameters and the patient's general condition. While searching for the triggering disease, a single cavitary lesion in the right lung was revealed in a chest radiograph. Computed tomography scan, bronchoscopy, and additional laboratory testing did not reveal a definitive cause of the lesion. We suspect that the lesion may be a consequence of HLH. The patient was disqualified from thoracic surgery due to multiple comorbidities. Even though HLH is a rare condition, it should be taken into consideration in a kidney transplant patient presenting with unspecific symptoms accompanied by a bicytopenia. It has an unpredictable course that often results in serious complications. Thus close follow-up of the patient and a wide array of imaging and laboratory tests remain crucial.

Amyloid storm: acute kidney injury and massive proteinuria, rapidly progressing to end-stage kidney disease in AA amyloidosis of familial Mediterranean fever

OBJECTIVE

Amyloid A nephropathy of FMF usually progresses over many years to end-stage renal disease (ESRD). We aim to describe an acute condition, termed here 'amyloid storm', typically manifesting with a rapid (≤2 weeks) increase in serum creatinine and urine protein, that has never been characterized in FMF amyloidosis.

METHODS

This retrospective analysis features amyloid storm by comparing between FMF amyloidosis patients who have experienced an episode of amyloid storm (study group) and matched patients who have not (control group). The primary outcome was ESRD or death within 1 year from study entry. Featured data were retrieved from hospital files.

RESULTS

The study and control groups, each comprising 20 patients, shared most baseline characteristics. However, they differed on the time from FMF onset to reaching serum creatinine of 1.2 mg/dl [26.5 years (s.d. 15.15) vs 41.55 (10.98), P = 0.001] and the time from the onset of proteinuria to study entry [8.8 years (s.d. 6.83) vs 15.75 (13.05), P = 0.04], culminating in younger age at study entry [39.95 years (s.d. 16.81) vs 48.9 (9.98), respectively, P = 0.05] and suggesting an accelerated progression of kidney disease in the study group. Within 1 year from study entry, 16 patients in the study and 3 in the control groups reached the primary endpoint (P = 0.000). The major triggers of amyloid storm were infections, occurring in 17 of 20 patients.

CONCLUSION

Amyloid storm is a complication of FMF amyloidosis, induced by infection and associated with poor prognosis and death.

CAR T-Cell Therapy: An Update for Radiologists

Chimeric antigen receptor-engineer (CAR) T-cell therapy is a promising novel immunotherapy that has the potential to revolutionize cancer treatment. With four CAR T-cell therapies receiving FDA approval within the last 5 years, the role of CAR T-cells is anticipated to continue to evolve and expand. However, various aspects of CAR T-cell therapies remain poorly understood, and the therapies are associated with severe side effects [including cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity (ICANS)] that require prompt diagnosis and intervention. In this review, we discuss the role of imaging in diagnosing and monitoring toxicities from CAR T-cell therapies and explore the application of various imaging techniques, including use of PET/CT with novel radiotracers, to predict and assess treatment response and adverse effects. It is important for radiologists to recognize the imaging findings associated with each syndrome, as well as the typical and atypical treatment response patterns associated with CAR T-cell therapy. Given the expected increase in use of CAR T-cells in the near future, radiologists should familiarize themselves with the imaging findings encountered in these novel therapies, to provide comprehensive and up-to-date guidance for clinical management.

Ruxolitinib is an alternative to etoposide for patient with hemophagocytic lymphohistiocytosis complicated by acute renal injury: A case report

INTRODUCTION

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening syndrome characterized by excessive production of inflammatory cytokines and multiple organs injury. Ruxolitinib, an oral selective JAK1/2 inhibitor, has recently shown efficacy and safety in the treatment of secondary HLH, which may be an alternative to intensive chemotherapy.

CASE REPORT

We report a case of a 2-year-old boy who presented to our institution with recurrent fever and acute renal failure. We made the diagnosis of Epstein-Barr virus related HLH based on the HLH-2004 protocol, and gave the treatment of ruxolitinib instead of etoposide.

MANAGEMENT AND OUTCOME

The patient received dexamethasone and continuous renal replacement therapy due to renal failure, but he still had fever and anuria. Given that the use of etoposide may deteriorate renal function, ruxolitinib was administered instead of etoposide. After 5 days of ruxolitinib treatment, the patient's fever was resolved and renal function also gradually recovered 14 days later.

DISCUSSION

Currently, dexamethasone, etoposide and cyclosporine A are the main drugs in HLH treatment. However, cytotoxic chemotherapy can temporally deteriorate organ damage and induce serious myelosuppression, which makes clinicians hesitate to implement these regimens. Ruxolitinib has shown efficacy in treating HLH without much toxicity in clinical trials. Thus, we suggest that ruxolitinib constitutes a treatment option for secondary HLH complicated by severe renal damage which may reduce toxic effects compared with intense chemotherapy.

Pulmonary granulomatosis of genetic origin

Granulomatous inflammation of the lung can be a manifestation of different conditions and can be caused by endogenous inflammation or external triggers. A multitude of different genetic mutations can either predispose patients to infections with granuloma-forming pathogens or cause autoinflammatory disorders, both leading to the phenotype of pulmonary granulomatosis. Based on a detailed patient history, physical examination and a diagnostic approach including laboratory workup, pulmonary function tests (PFTs), computed tomography (CT) scans, bronchoscopy with bronchoalveolar lavage (BAL), lung biopsies and specialised microbiological and immunological diagnostics, a correct diagnosis of an underlying cause of pulmonary granulomatosis of genetic origin can be made and appropriate therapy can be initiated. Depending on the underlying disorder, treatment approaches can include antimicrobial therapy, immunosuppression and even haematopoietic stem cell transplantation (HSCT). Patients with immunodeficiencies and autoinflammatory conditions are at the highest risk of developing pulmonary granulomatosis of genetic origin. Here we provide a review on these disorders and discuss pathogenesis, clinical presentation, diagnostic approach and treatment.

Pulmonary granulomatosis of genetic origin mostly occurs in immunodeficiency disorders and autoinflammatory conditions. In addition to specific approaches in this regard, the diagnostic workup needs to cover environmental and occupational aspects.https://bit.ly/31SqdHW

Screening for hemophagocytic lymphohistiocytosis in child abuse evaluations: Twelve years of data

BACKGROUND

Laboratory evaluation is commonly integrated into evaluation of children with suspected physical abuse to identify occult injury and potential mimics of abuse, including hemophagocytic lymphohistiocytosis (HLH). We evaluated the utility of ferritin in laboratory screening panels for physical abuse.

OBJECTIVE(S)

To determine if hyperferritinemia is a useful screening marker of HLH in physical abuse diagnostic evaluations.

PARTICIPANTS AND SETTING

Children being evaluated for physical abuse at a quaternary pediatric referral and level one trauma center in Houston, Texas.

METHODS

We conducted a 12-year (2003 - 2015) retrospective descriptive analysis of all ferritin values obtained as part of routine screening panels for physical child abuse. Medical records were abstracted for patients with ferritin > 500 ng/mL.

RESULTS

2954 ferritin levels were obtained in 3091 encounters for suspected physical abuse (median age 6.5 months, interquartile range 2.3-23.5 months). Elevated ferritin was found in 82/2954 (2.8 %); no child evaluated for physical abuse was found to have HLH (95 % CI: 0-4.5%). The child abuse team was consulted in 48/82 (58.5 %) of cases, with the final impression being physical abuse in 33/48 (68.8 %).

CONCLUSIONS

We found no instances where HLH was identified by institutional screening panels. The inclusion of ferritin in the screening panel was not beneficial. The presence of hyperferritinemia should not cast medical or legal doubt on physical abuse diagnoses when there is a high index of clinical suspicion. Novel hypotheses from case reports and case series should be studied more rigorously before affecting system change.

Atypical neuroimaging characteristics of hemophagocytic lymphohistiocytosis in infants: a case series of hemorrhagic brain lesions in the deep grey matter

Hemophagocytic lymphohistiocytosis (HLH) is a rare multisystem condition associated with uncontrolled overproduction and infiltration of lymphocytes and histiocytes predominantly in liver, lymph nodes, spleen, and central nervous system. Neuroimaging findings on MRI are fairly nonspecific and classically include periventricular white matter signal abnormalities and diffuse atrophy. Focal parenchymal lesions may demonstrate post contrast ring or nodular enhancement and calcification. However, the MR imaging characteristics can be highly variable. Here, we present two cases of HLH in infants with multiple hemorrhagic lesions mostly depicted in both thalami and basal ganglia regions. Thalamic, basal ganglia, and brain stem involvement with hemorrhagic changes in HLH are rarely described in literature. Early diagnosis of HLH may be lifesaving. Awareness of the disease is necessary to investigate its characteristic findings and avoiding a delay in diagnosis.

MRI findings of central nervous system involvement in children with haemophagocytic lymphohistiocytosis: correlation with clinical biochemical tests

AIM

To investigate the brain magnetic resonance imaging (MRI) features of children with haemophagocytic lymphohistiocytosis (HLH) with central nervous system (CNS) involvement, and to investigate the correlation with clinical biochemical tests.

MATERIAL AND METHODS

Clinical and MRI data were collected from 118 children with HLH-CNS between January 2012 and June 2019. Patients were grouped according to their MRI findings, and statistical methods were used to test for correlations between the MRI findings and biochemical variables.

RESULTS

Patients were divided into three groups, including normal appearance (Group 1, 17/118), diffuse parenchymal volume loss (Group 2, 44/118), and brain parenchyma lesions (Group 3, 57/118) containing three subtypes of brain lesions and HLH-CNS complications. Comparing biochemical values among the three groups revealed a significant difference for all values (p<0.05), except for cell counts in the cerebrospinal fluid (CSF). A pairwise comparison further showed significant inter-group differences for most of the variables. Spearman's rank correlation coefficient also demonstrated that CSF cell counts (r=0.193, p=0.036), CSF microprotein content (r=0.379, p<0.001), serum aspartate aminotransferase (AST; r=0.521, p<0.001), serum lactate dehydrogenase (LDH; r=0.514, p<0.001) and activated partial thromboplastin time (APTT; r=0.326, p<0.001) correlated positively with the MRI groups, while platelet count (PLT; r=-0.633, p<0.001) and plasma fibrinogen (FIB; r=-0.258, p=0.005) correlated negatively.

CONCLUSION

Classification of brain MRI findings of HLH-CNS correlates well with the results of several key biochemical tests. Brain MRI is a promising method to elucidate illness severity and clinical outcomes.

Hemophagocytic Lymphohistiocytosis: Lessons Learned from the Dark Side

Hemophagocytic lymphohistiocytosis (HLH) is a rare but severe form of immune dysregulation often presenting as unremitting fever, cytopenia, hepatosplenomegaly, coagulopathy, and elevation of typical HLH biomarkers. HLH is universally fatal, if left untreated. The HLH-2004 criteria are widely used to diagnose this condition, but there is growing concerns across different settings that its application may result in undertreatment of certain patients. There is an expanding spectrum of genetic conditions that can be complicated by HLH. This review summarizes the current concepts in HLH, the lessons learned from the past, and provide an overview of the latest diagnostic and treatment modalities.

Neuroinflammatory Disease as an Isolated Manifestation of Hemophagocytic Lymphohistiocytosis

Isolated neuroinflammatory disease has been described in case reports of familial hemophagocytic lymphohistiocytosis (FHL), but the clinical spectrum of disease manifestations, response to therapy and prognosis remain poorly defined. We combined an international survey with a literature search to identify FHL patients with (i) initial presentation with isolated neurological symptoms; (ii) absence of cytopenia and splenomegaly at presentation; and (iii) systemic HLH features no earlier than 3 months after neurological presentation. Thirty-eight (20 unreported) patients were identified with initial diagnoses including acute demyelinating encephalopathy, leukoencephalopathy, CNS vasculitis, multiple sclerosis, and encephalitis. Median age at presentation was 6.5 years, most commonly with ataxia/gait disturbance (75%) and seizures (53%). Diffuse multifocal white matter changes (79%) and cerebellar involvement (61%) were common MRI findings. CSF cell count and protein were increased in 22/29 and 15/29 patients, respectively. Fourteen patients progressed to systemic inflammatory disease fulfilling HLH-2004 criteria at a mean of 36.9 months after initial neurological presentation. Mutations were detected in PRF1 in 23 patients (61%), RAB27A in 10 (26%), UNC13D in 3 (8%), LYST in 1 (3%), and STXBP2 in 1 (3%) with a mean interval to diagnosis of 28.3 months. Among 19 patients who underwent HSCT, 11 neurologically improved, 4 were stable, one relapsed, and 3 died. Among 14 non-transplanted patients, only 3 improved or had stable disease, one relapsed, and 10 died. Isolated CNS-HLH is a rare and often overlooked cause of inflammatory brain disease. HLH-directed therapy followed by HSCT seems to improve survival and outcome.

Clinical and imaging features in adult patients with bone marrow haemophagocytosis with and without haemophagocytic lymphohistiocytosis: a single-institution experience

AIM

To evaluate clinical, laboratory, imaging findings, and outcomes of adult patients with bone marrow haemophagocytosis (BMH) who meet the diagnostic criteria for haemophagocytic lymphohistiocytosis (HLH) with those who do not meet the criteria.

MATERIALS AND METHODS

A pathology database search was performed from 2009 to 2019 to identify adult patients with BMH. Electronic medical records of 41 patients were reviewed to distinguish those who fulfil the HLH-2004 diagnostic guidelines, which identified 22 patients (11 men; mean age, 53.5 years) who met the criteria (HLH+) and 19 patients (13 men; mean age, 54.7 years) who did not meet the criteria (HLH-). Multi-modality imaging was reviewed to record imaging features. Clinical, laboratory, imaging findings, and outcomes were compared between the two groups using Fisher's exact test and Wilcoxon test.

RESULTS

Malignancy (non-Hodgkin's lymphoma) was the major trigger for both groups. 86% of HLH+ and 31% of HLH- patients presented with fever. Compared to the HLH- group, the HLH+ group exhibited higher serum ferritin, triglycerides, and lower fibrinogen levels (p<0.05). Alveolar opacities and hepatosplenomegaly were the most common imaging findings identified in both groups. Median overall survival of HLH+ and HLH- were 123.5 (interquartile range [IQR]: 40.7-681.7 days) and 189 days (IQR: 52-1680 days), respectively. Distribution of imaging features and overall survival did not differ between the groups.

CONCLUSION

Malignancy is the major trigger for BMH in both HLH+ and HLH- groups. HLH+ and HLH- groups have similar imaging manifestations or clinical outcomes. Therefore, presence of BMH alone is correlated with high morbidity and mortality.

Genomics and Radiogenomics in Inherited Neurometabolic Disorders - A Practical Primer for Pediatricians

Advances in genetics has revolutionised the way we understand, diagnose and manage neurological disorders. Notwithstanding the fact that genetic confirmation has already become standard of care in routine clinical practice, radiological and clinical phenotyping has not diminished in value; in fact it has found an enhanced role in guiding and interpreting genetic test results. Inherited neurometabolic disorders are a prominent group of disorders which are seen commonly in clinical practice and many are potentially treatable. The concept of Radiogenomics is the bridge from phenotype to genotype and the strength of association varies widely across different inherited metabolic diseases. Understanding the strengths and limitations of these correlations forms the basis of success of multidisciplinary approach to diagnose these disorders. In this article authors give a brief overview of the genetic basis of a disease, available genetic tests and the prominent role of radiology in contemplating a diagnostic suspicion and guiding further confirmatory tests.

Hemophagocytic syndrome with acute kidney injury accompanied by erythrophagocytic macrophages in the tubular lumen

Hemophagocytic syndrome (HPS) is a life-threatening syndrome involving excessive immune activation. It is often accompanied by renal involvement known as acute kidney injury (AKI), which is a poor prognostic factor of HPS. Thus, early diagnosis and treatment are very important. However, it is rarely identified in renal biopsy specimens, and its major manifestation is acute tubular necrosis. We report a rare case of erythrophagocytic macrophage presence in the tubular lumen of a patient with HPS-associated AKI. A kidney biopsy showed acute tubular necrosis, interstitial massive macrophage infiltration, and phagocytic macrophage casts without glomerular change. Some arteriolar vascular smooth muscle cells showed vacuolization because they were positive for α-smooth muscle actin. The patient's renal function improved after methylprednisolone pulse therapy followed by oral prednisolone after a month. Our case presents a new pathologic pattern of HPS. Careful urinalysis could suggest renal involvement with HPS. Having knowledge of this pathologic pattern of HPS is important to recognize the disease and to treat it appropriately.

An unusual case of hemophagocytic lymphohistiocytosis diagnosed by spinal nerve root biopsy

Hemophagocytic lymphohistiocytosis (HLH) is a rare disease process characterized by aberrant immune system activation and an exaggerated inflammatory response. Establishing the diagnosis may be challenging and is achieved by satisfying a number of clinical criteria, in addition to demonstrating tissue hemophagocytosis. This syndrome is rapidly fatal if prompt diagnosis and treatment are not achieved. The authors present the case of a 17-year-old male patient with CNS HLH involving both the brain and spinal cord, highlighting the variable CNS manifestations in pediatric patients with HLH and the challenges that accompany establishing diagnosis.

Transient periportal hyperechogenicity in feverish patients: a novel ultrasonographic finding

PURPOSE

Periportal hyperechogenicity has been recorded in many inflammatory and infectious diseases, including viral hepatitis, inflammatory bowel diseases, toxic shock syndrome of staphylococcus infection, typhoid fever, and schistosomiasis. We aimed to evaluate the echogenicity of the portal tracts of the liver by abdominal ultrasound imaging in patients with fever irrespective of the cause.

METHODS

Abdominal ultrasound examination was performed in 277 consecutive patients presented with fever at their first visit and repeated 2 weeks later after their recovery.

RESULTS

Transient periportal hyperechogenicity was present in 39% (108 patients) of the feverish patients studied irrespective of the cause of the fever.

CONCLUSION

Transient periportal hyperechogenicity is a frequent ultrasonographic finding in feverish patients irrespective of the cause of fever, and hence should not be misdiagnosed as liver disease or chronic periportal fibrosis unless the hyperechogenicity persists after recovery from the febrile or inflammatory condition.

Central Nervous System Involvement in 179 Chinese Children with Hemophagocytic Lymphohistiocytosis

Background:

Central nervous system (CNS) involvement is found in many patients with hemophagocytic lymphohistiocytosis (HLH). In this study, we mainly analyzed neurological symptoms, imaging findings, cerebrospinal fluid (CSF), and their relationship with outcomes of HLH children.

Methods:

Related data of 179 Chinese pediatric patients with HLH admitted to our center from January 2010 to December 2015 were analyzed retrospectively. Diagnosis and treatment were based on the HLH-2004 protocol. Two-tailed Chi-squared test was used to compare between different groups, and Kaplan-Meier survival curves were used to analyze the overall survival (OS) of patients with HLH.

Results:

In the present study, 21.2% (38/179) of total patients had neurological symptoms including seizure, irritability, somnolence, and unconsciousness. There were 80 (50.0%, excluding 19 patients without imaging data) patients with cranial imaging abnormalities. There were 14.7% (17/116, excluding 63 patients who did not accept lumbar puncture) of patients with abnormal CSF results. CNS involvement is defined as abnormalities in one or more of CNS symptoms, radiological findings, and CSF. Thus, 60.3% of them had CNS involvement. As for the prognosis, the median follow-up time was 3.2 years (17 lost to follow-up). The probable 3-year OS of children was higher without CNS involvement (86.0% ± 4.6%) than those with CNS involvement (68.9% ± 4.9%, hazard ratio [HR] = 2.286, P = 0.019). Among them, the probable 3-year OS of children without CNS symptoms was 76.0% ± 3.8%, higher than with CNS symptoms (59.5% ± 8.1%, HR = 2.147, P = 0.047). The 3-year OS of children with abnormal CSF was 64.7% ± 11.6%, compared with normal CSF (85.1% ± 3.7%, HR = 0.255, P = 0.038).

Conclusions:

HLH patients with CNS involvement might have worse outcomes compared with those without CNS involvement, and CNS symptoms and CSF changes are more important to access the prognosis than imaging abnormality.

Imaging of Childhood Inflammatory Brain Diseases

Brain has been considered as an immune-privileged site for centuries owing to the presence of blood-brain barrier, absent lymphatic drainage, and antigen-presenting cells. However, the present prevailing concept is of immune surveillance where brain is continuously surveyed by immune cells. However, the presence of immune cells in central nervous system (CNS) brings the risk of inflammation and autoimmunity involving both T and B cell mediated pathways. These mechanisms form the underlying pathology in a wide spectrum of pediatric CNS diseases manifesting as acquired neurological deficits. Overlapping, heterogenous, and ambiguous clinical features often delays the diagnosis. Although not always pathognomonic, magnetic resonance imaging can be an important biomarker leading to early diagnosis, prognostication, and systematic follow-up pf these diseases. This review describes the spectrum of different pediatric inflammatory disorders and their pertinent imaging features illustrated with clinical examples.

Imaging of Histiocytosis in the Era of Genomic Medicine

Histiocytosis describes a group of diseases that have long been considered enigmatic in the history of medicine. Recently, novel genomic analyses have identified somatic oncogenic driver mutations responsible for the pathogenesis of these entities. These discoveries have led to the recharacterization of histiocytoses as neoplastic diseases and have opened a new era of precision medicine approaches for treatment. The histiocytic disorders demonstrate a variety of imaging manifestations involving multiple organ systems, and radiologists play a major role in diagnosis and monitoring. An up-to-date knowledge of the novel genomic discoveries and their implications is essential for radiologists to understand the new approaches to treating histiocytic disorders and to contribute as key members of the multidisciplinary treatment team. This article provides a cutting-edge review of the novel concepts in histiocytosis, with a focus on recent genomic discoveries and precision medicine approaches to treating the disease, and describes imaging manifestations with correlative histologic and genomic findings, with an emphasis on adult-onset cases and uncommon subtypes. ^©RSNA, 2018.

Traumatic shaking: The role of the triad in medical investigations of suspected traumatic shaking

The Swedish Agency for Health Technology Assessment and Assesment of Social Services (SBU) is an independent national authority, tasked by the government with assessing methods used in health, medical and dental services and social service interventions from a broad perspective, covering medical, economic, ethical and social aspects. The language in SBU's reports are adjusted to a wide audience. SBU's Board of Directors has approved the conclusions in this report. The systematic review showed the following graded results: There is limited scientific evidence that the triad (Three components of a whole. The triad associated with SBS usually comprises subdural haematoma, retinal haemorrhages and encephalopathy.) and therefore, its components can be associated with traumatic shaking (low-quality evidence). There is insufficient scientific evidence on which to assess the diagnostic accuracy of the triad in identifying traumatic shaking (very low-quality evidence). Limited scientific evidence (low-quality evidence) represents a combined assessment of studies of high or moderate quality which disclose factors that markedly weaken the evidence. It is important to note that limited scientific evidence for the reliability of a method or an effect does not imply complete lack of scientific support. Insufficient scientific evidence (very low-quality evidence) represents either a lack of studies or situations when available studies are of low quality or show contradictory results. Evaluation of the evidence was not based on formal grading of the evidence according to GRADE but on an evaluation of the total scientific basis.

[CME: Acquired Hemophagocytic Lymphohistiocytosis]

CME: Acquired Hemophagocytic Lymphohistiocytosis Abstract. Acquired hemophagocytic lymphohistiocytosis comprises a heterogenous group of hyperinflammatory immunoreactions often resulting in uncontrolled immune responses, mainly throughout proliferation of cytotoxic T cells and hemophagocytosis by macrophages. Hemophagocytic lymphohistiocytosis is often underdiagnosed, contributing to its high morbidity and mortality. A systematic diagnostic approach and the use of established diagnostic criteria should lead to an early diagnosis, which is crucial for any therapeutic attempt to achieve a curative state of the disease.

Atteinte rénale du syndrome d’activation macrophagique

Le syndrome d’activation macrophagique (SAM) ou syndrome hémophagocytaire est une pathologie compliquant soit certains déficits immunitaires d’origine génétique, soit certaines maladies hématologiques (essentiellement des lymphomes non hodgkiniens), infectieuses (herpèsvirus, bactéries, parasites) ou auto-immunes (lupus, maladie de Still). Il se caractérise par une suractivation aiguë du système immunitaire et plus particulièrement des lymphocytes T cytotoxiques et des cellules histiocytaires/macrophagiques, déclenchant une production massive de cytokines pro-inflammatoires avec fièvre, pancytopénie, organomégalie, altérations du bilan hépatique et de la coagulation. Une défaillance multiviscérale est fréquente, nécessitant la prise en charge en réanimation et mettant souvent en jeu le pronostic vital, avec une mortalité qui reste dans certains cas à près de 50 %. Le SAM implique souvent le rein, par le biais d’une nécrose tubulaire aiguë, d’une néphropathie interstitielle inflammatoire ou d’une glomérulopathie sévère, responsable de syndrome néphrotique. La mise en évidence de ce syndrome n’est pas toujours facile chez un patient avec un tableau de sepsis ou de choc septique, mais elle peut guider la prise en charge thérapeutique, notamment l’initiation d’un traitement par chimiothérapie ou immunosuppresseurs, selon l’étiologie identifiée.

[Prognosis of the central nervous system involvement in patients with hemophagocytic lymphohistiocytosis]

Objective: To investigate the characteristics and prognostic factor of central nervous system (CNS) involvement in patients with hemophagocytic lymphohistiocytosis (HLH) . Methods: From January 2006 to October 2015, 152 patients with HLH, 88 patients had CNS involvement, their clinical data were collected, and survival was analyzed using the Kaplan-Meier life table method, univariate and multivariate Cox regression model analyses were applied to identify the risk factors of prognosis. Results: ①57.9% patients complicated with neurological symptoms, cerebrospinal fluid abnormalities were observed in 37.0% patients, 57.5% patients had abnormal neuroradiology. ②36 patients survived well, 3 patients lost to follow-up, 49 dead, 1 survival patient had epilepsy. ③The 3-year overall survival rate of 88 patients was 44%. ④abnormal CSF and unreceived IT bore a significant, independent adverse prognostic value (P<0.05) . Conclusion: CNS involvement in HLH has a high frequency and poor prognosis, few patients remained neurologic sequelae; abnormal CSF related to poor prognosis, positive intrathecal injections could improve the prognosis.

Central nervous system involvement in adults with haemophagocytic lymphohistiocytosis: a single-center study

Hemophagocytic lymphohistiocytosis (HLH) is a rare multisystem disorder characterized by proliferation and diffuse infiltration multiple organs with histiocytes, including the central nervous system (CNS). Neurological manifestations of HLH have been recognized in different studies with children, but they remain relatively ill-defined in adults with HLH. From March 2008 to October 2014, 289 adult patients with HLH were admitted to our center. Clinical, radiological, and cerebral spinal fluid (CSF) data of the patients with CNS involvement were reviewed, and a retrospective study in our single-center was carried out. CNS involvement was observed in 29 patients (10%) either in their diagnosis process or during disease course. CNS symptoms included disturbance of consciousness, cranial nerve palsies, seizures, headache, limb paralysis, irritability, meningism, and memory loss. CSF analysis was conducted in 17 patients (59%). Among them, 11 patients (65%) were reported as having abnormal CSF. Neuroradiological studies were performed in 25 patients (86%). Among the 13 cases that underwent CT scan, one patient hemorrhaged. Single or multiple hypodense foci were detected in the other 2 patients. Magnetic resonance imaging (MRI) abnormalities were found in 15 patients, including focal lesions in cortical and adjacent subcortical regions with or without variable nodular or ring contrast-enhancement, multiple lesions in white matter, diffuse white matter signal changes, and meningeal enhancement. Basal ganglia, cerebellum, and brainstem lesions were also observed. CNS involvement could also be found in adult patients with HLH, but not as frequent as it was in children. The clinical manifestations could be diversified. By carrying out rigorous CNS examinations, an early diagnosis could be made and it was of the utmost importance for the prevention of further lesions.

Clinical features and prognostic factors of adult secondary hemophagocytic syndrome: Analysis of 47 cases

This study aimed to investigate the relationship between clinical features and prognosis of adult secondary hemophagocytic syndrome (HPS).A retrospective analysis was conducted on the pathogenesis, clinical manifestations, laboratory examinations, treatment options, and prognosis of 47 patients with adult secondary HPS diagnosed from January 2013 to December 2015.The average age at disease onset was (46.26 ± 18.98) years with a male:female ratio of 1:1.14. Thirteen patients died, with the highest mortality rate in patients with HPS underlying blood system malignancy (33.33%, 2/6). The mortality rate in patients with HPS underlying autoimmune disorders was the lowest (18.75%, 3/16). The Kaplan-Meier analysis indicated that signs of hemorrhage, pulmonary and nervous system involvement, serous effusion, and decrease in the blood platelet count were associated with death. The Cox regression analysis revealed that signs of hemorrhage, pulmonary involvement, serous effusion, and nervous system involvement were independent risk factors of patient death.Adult secondary HPS has multiple etiologies and diversified clinical features. The risk of death increases in patients with signs of hemorrhage, serous effusion, pulmonary involvement, and nervous system involvement.

Capillary leak syndrome: etiologies, pathophysiology, and management

In various human diseases, an increase in capillary permeability to proteins leads to the loss of protein-rich fluid from the intravascular to the interstitial space. Although sepsis is the disease most commonly associated with this phenomenon, many other diseases can lead to a "sepsis-like" syndrome with manifestations of diffuse pitting edema, exudative serous cavity effusions, noncardiogenic pulmonary edema, hypotension, and, in some cases, hypovolemic shock with multiple-organ failure. The term capillary leak syndrome has been used to describe this constellation of disease manifestations associated with an increased capillary permeability to proteins. Diseases other than sepsis that can result in capillary leak syndrome include the idiopathic systemic capillary leak syndrome or Clarkson's disease, engraftment syndrome, differentiation syndrome, the ovarian hyperstimulation syndrome, hemophagocytic lymphohistiocytosis, viral hemorrhagic fevers, autoimmune diseases, snakebite envenomation, and ricin poisoning. Drugs including some interleukins, some monoclonal antibodies, and gemcitabine can also cause capillary leak syndrome. Acute kidney injury is commonly seen in all of these diseases. In addition to hypotension, cytokines are likely to be important in the pathophysiology of acute kidney injury in capillary leak syndrome. Fluid management is a critical part of the treatment of capillary leak syndrome; hypovolemia and hypotension can cause organ injury, whereas capillary leakage of administered fluid can worsen organ edema leading to progressive organ injury. The purpose of this article is to discuss the diseases other than sepsis that produce capillary leak and review their collective pathophysiology and treatment.

Hemi-meningitis with hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a rare lymphoproliferative disorder. HLH may occur as a complication of Epstein-Barr virus (EBV), particularly in patients with immunodeficiencies. Herein, we describe a 16-year-old girl with neurological complications associated EBV-induced HLH. Her cerebral magnetic resonance imaging (MRI) showed contrast-enhanced axial T1-weighted images with enhancement of meningeal surface in the right hemisphere that was consistent with right hemi-meningitis. Hydrocephalus, dilated subdural spaces, delayed myelination, edema, diffuse parenchymal atrophy, calcifications, diffuse/patchy white matter abnormalities have all been previously described with HLH. To the best of our knowledge, this is the first case of hemi-meningitis associated with HLH. We suggest that clinicians should consider HLH with vascular disorders when they determine unilateral meningitis on a brain MRI.

Spectrum of abdominal imaging findings in histiocytic disorders

OBJECTIVES

The present article provides an overview of the spectrum of abdominal findings of histiocytic disorders that may be observed in multimodality imaging illustrated by clinical cases from our Imaging Center.

METHODS

We will review abdominal findings of Langerhans cell histiocytosis, Rosai-Dorfman disease, Erdheim-Chester disease, and hemophagocytic syndrome illustrated by clinical cases from our imaging department with histologic correlation.

RESULTS

Abdominal involvement of histiocytic disorders is rare and may occur in the liver, biliary tract, kidney, retroperitoneum, kidney, gastrointestinal tract, and lymph nodes.

CONCLUSION

Histiocytic disorders encompass a group of rare diseases with a wide range of manifestations in which the abdominal involvement is quite infrequent. The role of the radiologist is to report the major imaging findings and the differential diagnosis; however, the imaging features are unspecific and biopsy usually is necessary to establish the definitive diagnosis.

Pulmonary Involvement in Patients With Hemophagocytic Lymphohistiocytosis

BACKGROUND

Acquired hemophagocytic lymphohistiocytosis (HLH) is a life-threatening event that usually occurs as a complication of immunodeficiency. Lung involvement in HLH has received little attention. This article describes lung involvement in HLH and assesses whether it affects the prognosis.

METHODS

We retrospectively studied 219 patients with HLH admitted to a national reference center over a 14-year period, including 118 (54%) with lung involvement.

RESULTS

Dyspnea and cough were the most common onset symptoms. Radiographs revealed interstitial infiltrates with centrilobular nodules, ill-defined consolidation, or localized ground-glass opacities. Pleural effusions and mediastinal lymphadenopathies were found in approximately one-half of the patients. One or more causes of lung involvement were documented in 91 of 118 patients (77.1%) and included infection (n = 52), pulmonary edema (n = 34), and malignancies (n = 22 [mostly lymphoma]). HLH-specific treatment combined with treatment of the cause of lung involvement improved respiratory function in only 67 of the 188 patients (56.7%). Hospital mortality was higher in patients with lung involvement (52.5% vs 20%). Infection as the cause of lung involvement was the only determinant of death (56% vs 30%; P = .004).

CONCLUSIONS

Lung involvement is common and of poor prognosis in patients with HLH. Studies should assess whether specific diagnostic and therapeutic strategies are warranted in patients with HLH and lung involvement.

Hemophagocytic Syndrome With Histiocytic Glomerulopathy and Intraglomerular Hemophagocytosis

Hemophagocytic syndrome (HPS), a rare and life-threatening disease, is characterized by hyperactivation of the immune system that causes hypercytokinemia and potential multiorgan failure. Acute kidney injury is the most common kidney manifestation of HPS and is generally considered a poor prognostic factor. Glomerular involvement is uncommon and usually manifests as either podocytopathy with collapsing glomerulopathy or thrombotic microangiopathy. We report a rare case of severe histiocytic glomerulopathy in a patient with HPS who presented with acute kidney injury and proteinuria. Kidney biopsy revealed massive glomerular infiltration by macrophages resembling proliferative glomerulonephritis accompanied by intraglomerular hemophagocytosis and mild features of glomerular thrombotic microangiopathy. The patient's kidney failure and proteinuria responded rapidly to high-dose pulse methylprednisolone followed by a tapering course of oral prednisone. Our case expands the renal pathologic spectrum of HPS to include histiocyte-rich glomerular infiltration and intraglomerular hemophagocytosis. Greater awareness of this entity is needed to ensure prompt recognition and appropriate therapy.

So-called Acute Acalculous Cholecystitis in Macrophage Activation Syndrome

Acute acalculous cholecystitis (AAC) is a severe disease seen in critically ill patients, including those with autoimmune diseases. We herein report the case of a 41-year-old female who developed macrophage activation syndrome (MAS) accompanied by a recurrence of Kikuchi disease. Abdominal imaging revealed marked thickening of the gallbladder wall and pericholecystic fluid, typically found in AAC. Treatment with intravenous pulse methylprednisolone induced in a significant improvement in the gallbladder wall, resulting in no need for surgical intervention. We should consider that patients with MAS may therefore sometimes develop AAC and that early immunosuppressive therapy can be effective in AAC cases associated with rheumatic or autoimmune diseases.

Progressive Diffuse Osteonecrosis in a Patient with Secondary Hemophagocytic Lymphohistiocytosis

This is a case report with serial imaging showing progression of diffuse osteonecrosis in a patient after a diagnosis of secondary hemophagocytic lymphohistiocytosis (HLH). While bone marrow involvement in HLH has been long noted at histological evaluation and is itself one of the diagnosis criteria, to the best of our knowledge, there has been no previous publication addressing osseous image findings in a patient with HLH.

The significance of pre-therapeutic F-18-FDG PET-CT in lymphoma-associated hemophagocytic lymphohistiocytosis when pathological evidence is unavailable

Purpose

The significance of positron emission tomography/computed tomography (PET–CT) in identifying patients with lymphoma-associated hemophagocytic lymphohistiocytosis (LAHLH) when pathological evidence is unavailable remains uncertain.

Methods

In this retrospective study, 44 HLH patients who underwent PET–CT before clinical treatment were enrolled, and 18 of them were highly suspected as LAHLH by PET–CT. We compared the PET–CT parameters between confirmed LAHLH and non-LAHLH patients. The efficacy of initial therapies for highly suspected LAHLH patients was analyzed as well.

Results

We found that the SUV_Sp, SUV_BM, SUV_LN, SUV_max, SUV_LN/Li, and SUV_max/Li in LAHLH group were significantly higher than those in non-LAHLH group (p = 0.003, p = 0.034, p = 0.003, p < 0.001, p = 0.039, and p = 0.035, respectively). HLH patients with an SUV_max value >5.5, an SUV_LN value >3.3, and an SUV_Sp value >4.8 were more likely to be LAHLH (p < 0.001, p = 0.003, and p = 0.003, respectively). And the incidence of multiple lymphadenopathy with increased FDG uptake or the incidence of multiple bone lesions in LAHLH patients was significantly higher than those in non-LAHLH group (92.9 vs. 35.7 %, p = 0.004; 42.9 vs. 0 %, p = 0.016, respectively). Furthermore, by comparing the efficacy of initial therapies for highly suspected LAHLH patients (n = 18), we indicated that the CR rate was significantly higher in lymphoma-chemotherapy group than in immunosuppressive therapy group (90 and 25 %, respectively; p = 0.013). OS analysis revealed that highly suspected LAHLH patients treated with lymphoma-chemotherapy had better prognosis (264 days) than those treated with immunosuppressive therapy (15 days) (p < 0.0001).

Conclusions

When pathological evidence is absent, PET–CT may play an important role in identifying HLH patients underlying lymphoma. Once highly suspected as LAHLH by PET–CT, lymphoma-chemotherapies that directly treat the underling lymphoma may have a relatively favorable effect and better clinical outcomes than immunosuppressive therapy.

More than just Langerhans cell histiocytosis: a radiologic review of histiocytic disorders

Although Langerhans cell histiocytosis (LCH) is a familiar entity to most radiologists and to pediatric radiologists in particular, it is but one of a group of disorders caused by the overproduction of histiocytes, a subtype of white blood cells. Other less familiar diseases in this category are Erdheim-Chester disease (ECD), juvenile xanthogranuloma (JXG), Rosai-Dorfman disease (RDD), and hemophagocytic lymphohistiocytosis (HLH). This review describes the classification system, clinical manifestations, and pathophysiology of each disease, with particular attention to differential radiographic findings, including typical locations of involvement and varying appearances at radiography, computed tomography, magnetic resonance imaging, ultrasonography, and nuclear medicine imaging. Although LCH has a wide variety of manifestations and appearances, classic imaging findings include vertebra plana, skull lesions with a beveled edge, the "floating tooth" sign, bizarre lung cysts, and an absent posterior pituitary bright spot with infundibular thickening. The classic imaging findings of ECD are a perirenal rind of soft tissue and patchy long bone osteosclerosis. RDD has more nonspecific imaging findings, including lymphadenopathy (most commonly cervical) and intracranial lesions. Imaging findings in HLH are broad, with the most common abnormalities being hepatosplenomegaly, cerebral volume loss, and periventricular white matter abnormalities. JXG can manifest at imaging, but radiology does not play a major role in diagnosis. Familiarity with these disorders and their associated imaging findings facilitates correct and timely diagnosis. Imaging also features prominently in the assessment of treatment response.

Fever-triggered Brugada syndrome in an adult patient presenting with hemophagocytic syndrome induced by Chlamydophila pneumoniae

A previously healthy 29-year-old man was admitted to our hospital, with a 4-day history of fever (>39°C), rigours, diaphoresis, fatigue and retro-orbital headache. On examination, he was febrile (37.8°C) and tachycardic (110 bpm). Laboratory work up revealed bicytopenia (white cell count 1.37×10(9)/L, platelets 60×10(9)/L) and an increase in C reactive protein (9 mg/dL). The ECG showed ST segment elevation in V1, V2 and V3 leads. The patient was admitted and investigation was initiated revealing prolonged fever (>7 days), pancytopenia, hepatosplenomegaly, hyperferritinemia, hypertriglyceridemia, hypofibrinogenemia, elevated soluble CD25 and hemophagocytosis in bone marrow. Therefore, the patient presented 7 of the 8 diagnostic criteria of hemophagocytic syndrome. Laboratorial investigation for infectious causes was negative, except for IgA and IgG Chlamydophila pneumoniae. ECG re-evaluation on the day of discharge showed no ST segment elevation and no other abnormalities. Genetic testing for known mutations associated with hemophagocytic syndrome and Brugada syndrome did not show any mutations in these genes.

Cerebrospinal Fluid Markers of Macrophage and Lymphocyte Activation After Traumatic Brain Injury in Children

OBJECTIVES

The magnitude and role of the cellular immune response following pediatric traumatic brain injury remains unknown. We tested the hypothesis that macrophage/microglia and T-cell activation occurs following pediatric traumatic brain injury by measuring cerebrospinal fluid levels of soluble cluster of differentiation 163 and ferritin and soluble interleukin-2 receptor α, respectively, and determined whether these biomarkers were associated with relevant clinical variables and outcome.

DESIGN

Retrospective analysis of samples from an established, single-center cerebrospinal fluid bank.

SETTING

PICU in a tertiary children's hospital.

PATIENTS

Sixty-six pediatric patients after severe traumatic brain injury (Glasgow Coma Scale score < 8) who were 1 month to 16 years old and 17 control patients who were 1 month to 14 years old.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Cerebrospinal fluid levels of soluble cluster of differentiation 163, ferritin, and soluble interleukin-2 receptor α were determined by enzyme-linked immunosorbent assay at two time points (t1 = 17 ± 10 hr; t2 = 72 ± 15 hr) for each traumatic brain injury patient. Cerebrospinal fluid levels of soluble cluster of differentiation 163, ferritin, and soluble interleukin-2 receptor α after traumatic brain injury were compared with controls and analyzed for associations with age, patient sex, initial Glasgow Coma Scale score, diagnosis of abusive head trauma, the presence of hemorrhage on CT scan, and Glasgow Outcome Scale score. Cerebrospinal fluid level of soluble cluster of differentiation 163 was increased in traumatic brain injury patients at t2 versus t1 and controls (median, 95.4 ng/mL [interquartile range, 21.8-134.0 ng/mL] vs 31.0 ng/mL [5.7-77.7 ng/mL] and 27.8 ng/mL [19.1-43.1 ng/mL], respectively; p < 0.05). Cerebrospinal fluid level of ferritin was increased in traumatic brain injury patients at t2 and t1 versus controls (8.3 ng/mL [<7.5-19.8 ng/mL] and 8.9 ng/mL [<7.5-26.7 ng/mL] vs <7.5 ng/mL below lower limit of detection, respectively; p < 0.05). Cerebrospinal fluid levels of soluble interleukin-2 receptor α in traumatic brain injury patients at t2 and t1 were not different versus controls. Multivariate regression revealed associations between high ferritin and age 4 years or younger, lower Glasgow Coma Scale score, abusive head trauma, and unfavorable Glasgow Outcome Scale score.

CONCLUSIONS

Children with traumatic brain injury demonstrate evidence for macrophage activation after traumatic brain injury, and in terms of cerebrospinal fluid ferritin, this appears more prominent with young age, initial injury severity, abusive head trauma, and unfavorable outcome. Further study is needed to determine whether biomarkers of macrophage activation may be used to discriminate between aberrant and adaptive immune responses and whether inflammation represents a therapeutic target after traumatic brain injury.

Acute pulmonary complications in patients with hematologic malignancies

Various acute pulmonary complications may occur in patients with hematologic malignancies because they are in an immunocompromised state due to systemic disease or to chemotherapy or hematopoietic stem cell transplantation. Pulmonary complications may arise from other treatment regimens, as well, or from direct pulmonary involvement in the malignant disease process. The differential diagnosis of pulmonary opacities in patients with hematologic malignancies is broad and includes both infectious and noninfectious causes. Pulmonary hemorrhage, edema, leukostasis, and pneumonia are well-known and common acute pulmonary complications. Less common complications are now encountered with increasing frequency because of the increasing complexity of therapeutic regimens for hematologic malignancies, which may include various drugs that are in clinical trials or were recently released to market. These once uncommon acute pulmonary complications include retinoic acid syndrome, tyrosine kinase inhibitor-induced pulmonary complications, engraftment syndrome, and hemophagocytic lymphohistiocytosis. It is often difficult to differentiate between these entities. However, the clinical setting and radiologic imaging findings may provide clues for interpreting imaging findings of abnormal pulmonary opacity in patients with a hematologic malignancy. Pulmonary hemorrhage is characterized by a sudden onset of symptoms and rapid progression of pulmonary imaging abnormalities and usually occurs in patients with impaired coagulation or a predisposition to bleed. Pulmonary edema should be considered when typical findings of hydrostatic pulmonary edema are seen. Pulmonary leukostasis develops in patients with hyperleukocytosis and leads to symptoms such as a cough, fever, and dyspnea. Various types of pneumonia may develop, depending on the degree and duration of immunosuppression in the patient. Retinoic acid syndrome, tyrosine kinase inhibitor-induced pulmonary complications, and engraftment syndrome occur after specific treatments, so a detailed medical history including recent or current treatments may be helpful for diagnosis. Accurate differentiation of these entities allows their appropriate management, with resultant decreases in morbidity and mortality.