Diagnosing haemophagocytic syndrome

Hemophagocytic lymphohistiocytosis and macrophage activation syndrome: two rare sides of the same devastating coin

Hemophagocytic lymphohistiocytosis (HLH) is a rare genetic hyperinflammatory syndrome that occurs early in life. Macrophage activation syndrome (MAS) usually refers to a secondary form of HLH associated with autoimmunity, although there are other causes of secondary HLH, such as infections and malignancy. In this article, we reviewed the concepts, epidemiology, clinical and laboratory features, diagnosis, differential diagnosis, prognosis, and treatment of HLH and MAS. We also reviewed the presence of MAS in the most common autoimmune diseases that affect children. Both are severe diseases that require prompt diagnosis and treatment to avoid morbidity and mortality.

A qualitative investigation into the impact of hemophagocytic lymphohistiocytosis on children and their caregivers

Background

Primary hemophagocytic lymphohistiocytosis (pHLH) is a rare and life-threatening disorder, which usually occurs during infancy or early childhood and is characterized by abnormal activation of the immune system. However, the burden of pHLH on children and their families has not been previously evaluated. This qualitative study investigated the impact of pHLH and its treatment on the physical, emotional, and social well-being of patients and caregivers in the USA and UK using interviews to provide a comprehensive insight from the perspective of the caregivers and young survivors.

Results

Twenty-one caregivers were enrolled (median [range] age, 41.1 [26–58] years) and represented 20 patients, four from the UK and 16 from the USA. At enrollment, 17 of the 20 patients were alive with a median [range] age of 12.75 [5–31] years at a mean [range] of 7.8 [0.6–11.6] years after diagnosis. In addition, four adult survivors (median [range] age, 23.3 [21–30] years) were also enrolled (total participants n = 25). From noticing initial symptoms to receiving a diagnosis, caregivers reported a mean (range) of 25.9 (0–258) months. pHLH and its treatment had a substantial and long-lasting impact on patients and caregivers, affecting their physical, emotional and social well-being, family relationships, friendships, and ability to work and study. Many of the experiences reported were negative, even after curative treatment, and some participants experienced long-lasting physical and emotional issues. The most noticeable impact of pHLH for patients was on their physical well-being, whereas for caregivers it was emotional well-being. Across all participants there was a sense of isolation due to the illness and its treatment, particularly regarding the patient being immunocompromised and the fear of infection. Areas having a major impact and considered in need of improvement included: delays in diagnosis, lack of patient-specific information on pHLH and a lack of support and understanding about the condition.

Conclusions

pHLH placed a substantial burden on patients and caregivers, which for some were long-lasting. This was compounded by the lack of awareness and understanding of pHLH by healthcare professionals, and a lack of accessible information for those affected by pHLH.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-021-01832-2.

Macrophage Activation Syndrome in Children: Diagnosis and Management

Macrophage activation syndrome is a severe yet under-recognized complication encountered in pediatric rheumatology. It manifests as secondary hemophagocytic lymphohistiocytosis leading to a hyper-inflammatory state resulting from an underlying cytokine storm. If unchecked, it may lead to multiorgan failure and mortality. Early diagnosis and timely initiation of specific therapy is pivotal for a successful outcome. This review outlines the key clinical and laboratory features and management of macrophage activation syndrome.

Haemophagocytic lymphohistiocytosis secondary to brucellosis in a young child

Brucellosis is a common zoonotic disease worldwide. It has protean clinical manifestation and sometimes may has a life-threatening complication. A 4-year-old boy presented with a history of fever, myalgia and appetite loss for 3 weeks. On examination, he had hepatosplenomegaly. The initial working diagnosis was an infection, autoimmune disease and malignancy. Investigations showed positive Brucella serology, and he was started on rifampicin and cotrimoxazole. He was further investigated because of persistent fever, which revealed evidence of haemophagocytic lymphohistiocytosis (HLH). He continued treatment for brucellosis, except rifampicin which was replaced with doxycyclin due to a worsening liver function. The child showed complete clinical and biochemical improvement after 6 weeks of therapy. HLH is a life-threatening condition and should be suspected in children with brucellosis, who did not respond to appropriate antibiotics treatment. Secondary HLH does not always require specific therapy; it may improve with adequate treatment of the underlying condition.

Immunodeficiencies: non-infectious manifestations

OBJECTIVES

Classical immunodeficiencies are mainly characterized by infectious conditions. In recent years, manifestations related to allergy, inflammation, autoimmunity, lymphoproliferation, and malignancies related to this group of diseases have been described. The text intends to make an update on the non-infectious manifestations of the primary defects of the immune system.

SOURCE OF DATA

Searches were carried out in the PubMed database for review articles published in the last five years, in English, French, or Spanish, using the terms "allergy," "inflammation," "autoimmunity," "lymphoproliferation," "cancer," AND "immunodeficiency" or "primary immunodeficiency" or "inborn errors of immunity" NOT "HIV".

SYNTHESIS OF DATA

Non-infectious manifestations characterize the primary defects in which there is dysregulation of the immune system. The most common manifestations of autoimmunity in this group of diseases are autoimmune cytopenias. Exacerbated inflammatory processes, benign lymphoproliferation, and propensity to malignancy of the lymphoreticular system are related to several diseases in this group. Severe manifestations of atopy or food allergy characterize some immunodeficiencies. Disorders of inborn immunity of the autoinflammatory type are characterized by an aseptic inflammatory process in the absence of autoimmunity, with fever and recurrent manifestations in different organs.

CONCLUSIONS

Not only infectious conditions should raise the suspicion of immunodeficiencies, but also manifestations of allergy, inflammation, autoimmunity, lymphoproliferation, or cancer, especially if they are recurrent, associated to each other, affecting young patients, or in severe and/or difficult to treat conditions.

Immune cartography of macrophage activation syndrome in the COVID-19 era

A hyperinflammatory 'cytokine storm' state termed macrophage activation syndrome (MAS), culminating from a complex interplay of genetics, immunodeficiency, infectious triggers and dominant innate immune effector responses, can develop across disparate entities including systemic juvenile idiopathic arthritis (sJIA) and its counterpart adult-onset Still disease (AOSD), connective tissue diseases, sepsis, infection, cancers and cancer immunotherapy. Classifying MAS using the immunological disease continuum model, with strict boundaries that define the limits of innate and adaptive immunity, at one boundary is MAS with loss of immune function, as occurs in the 'perforinopathies' and some cases of sJIA-AOSD. Conversely, at the other boundary, immune hypersensitivity with gain of immune function in MHC class II-associated sJIA-AOSD and with chimeric antigen receptor (CAR) T cell therapy also triggers MAS. This provides a benchmark for evaluating severe inflammation in some patients with COVID-19 pneumonia, which cripples primary type I interferon immunity and usually culminates in a lung-centric 'second wave' cytokine-driven alveolitis with associated immunothrombosis; this phenomenon is generally distinct from MAS but can share features with the proposed 'loss of immune function' MAS variant. This loss and gain of function MAS model offers immune cartography for a novel mechanistic classification of MAS with therapeutic implications.

Macrophage activation syndrome in a newborn: report of a case associated with neonatal lupus erythematosus and a summary of the literature

BACKGROUND

Macrophage activation syndrome (MAS) is a life-threatening hyperinflammatory syndrome and is caused by a severely dysregulated immune response. It has rarely been associated with neonatal lupus.

CASE PRESENTATION

We present a female neonate with MAS born to a mother who had cutaneous lupus erythematosus with circulating anti-nuclear antibodies (ANA), anti-SSA, anti-SSB and anti-extractable nuclear antigen (anti-ENA) antibodies. Because of neonatal lupus (NLE) with a total atrioventricular block, epicardial pacemaker implantation was required on the sixth day of life. Following surgery she developed non-remitting fever and disseminated erythematous skin lesions. A diagnosis of MAS was made based on these symptoms, with hyperferritinemia, elevated transaminases, hypertriglyceridemia, and a skin biopsy that showed hemophagocytosis. Our patient was treated with steroids for 3 months with good effect. No relapse has occurred.

CONCLUSIONS

MAS is a rare complication of neonatal lupus that may be difficult to diagnose, but needs to be treated promptly. In this article, pathogenesis and overlap of MAS and hemophagocytic lymphohistiocytosis (HLH) has been described. Diagnosis of MAS can be difficult. Different diagnostic criteria are used in both diagnosing MAS and HLH. Validated criteria for diagnosis of MAS in other disease than systemic onset JIA have not been validated yet. In NLE, diagnosing MAS is even more difficult, since skin lesions are already common in NLE. We show the potential additional value of skin biopsy in diagnosing MAS.

In vivo tracking of transplanted macrophages with near infrared fluorescent dye reveals temporal distribution and specific homing in the liver that can be perturbed by clodronate liposomes

Macrophages play an indispensable role in both innate and acquired immunity, while the persistence of activated macrophages can sometimes be harmful to the host, resulting in multi-organ damage. Macrophages develop from monocytes in the circulation. However, little is known about the organ affinity of macrophages in the normal state. Using in vivo imaging with XenoLight DiR®, we observed that macrophages showed strong affinity for the liver, spleen and lung, and weak affinity for the gut and bone marrow, but little or no affinity for the kidney and skin. We also found that administered macrophages were still alive 168 hours after injection. On the other hand, treatment with clodronate liposomes, which are readily taken up by macrophages via phagocytosis, strongly reduced the number of macrophages in the liver, spleen and lung.

Cytomegalovirus and disseminated histoplasmosis-related hemophagocytic lymphohistiocytosis syndrome in an HIV-patient late presenter with IRIS: a case report

Background

Hemophagocytic lymphohistiocytosis syndrome (HLS) is an immune-mediated life-threatening disease considered as a medical emergency, with a potentially fatal multisystem inflammatory outcome. We present a patient that developed HLS and was able to be diagnosed efficiently with the help of an academic research institute of immunology.

Case presentation

A 21 years old male Mexican with human immunodeficiency virus (HIV), late presenter; who developed cytomegalovirus (CMV) infection and a disseminated histoplasmosis-related HLS, as part of an immune reconstitution inflammatory syndrome (IRIS). The patient required a long course of corticotherapy, intravenous immunoglobulin and massive transfusions (more than 10 units in 24 h, and a total of 83 units), besides amphotericin-B and ganciclovir treatment. An academic research institute of immunology aided in the accurate diagnosis of HLS with the implementation of tests not available within the hospital, thus improving the care provided to the patient. The patient recovered, was discharged, and continue to improve.

Conclusion

The objective of this report is to highlight the importance of having multidisciplinary support, including basic medical sciences groups providing specific tests that are sometimes very difficult to get, which provides a benefit to patients in the well-aimed diagnosis as part of applied translational medicine.

Awareness of Hemophagocytic Lymphohistiocytosis as an Unusual Cause of Liver Failure in the Neonatal Period

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening syndrome that predominantly affects infants from birth to 18 months of age, characterized by fever and multiorgan failure. Liver injury has been rarely reported as a presenting sign in the neonatal period. This study reports a case with HLH in the neonatal period who presented with acute liver failure.

CASE PRESENTATION

Herein, a 3-day-old female newborn was admitted with cytopenia, increased liver enzymes, hypofibrinogenemia, and markedly elevated serum ferritin. Hemophagocytosis of bone marrow biopsy confirmed the diagnosis of HLH. The newborn was treated with HLH-2004 protocol, but she finally died from multiorgan failure.

CONCLUSION

Growing awareness of HLH as a cause of liver failure in the neonatal period can be associated with early treatment and reduces mortality in this group of patients.

Hemophagocytic Syndrome Caused by Methotrexate Overdose in a Total Knee Arthroplasty Patient: A Case Report

CASE

We report a patient with rheumatoid arthritis (RA) who developed hemophagocytic syndrome (HPS). The HPS was attributed to sepsis, itself a consequence of methotrexate (MTX) overdose. The discovery of MTX overdose was facilitated by the presence of epidermolysis bullosa, multiple ulcers of the whole digestive tract, and additional history from the patient's family.

CONCLUSION

For arthroplasty patients with underlying inflammatory disorders such as RA, drug history should be thoroughly inquired. Correct diagnosis results from careful history review, detailed physical examination, and necessary laboratory tests.

Tuberculosis-Associated HLH in an 8-Month-Old Infant: A Case Report and Review

Hemophagocytic lymphohistiocytosis (HLH) is a rare immunological disease, which can be mistaken for sepsis easily. Among the infectious causes that may trigger secondary HLH, tuberculosis (TBC), a rather rare pathogen nowadays, is typical. To our knowledge, this is the first case report of an infant suffering from TBC-associated HLH-induced acute respiratory failure who was treated successfully using extracorporeal membrane oxygenation. An 8-month-old boy with fever (over the last 8 wk) and pancytopenia was transferred to our institution with acute respiratory failure and for extracorporeal membrane oxygenation therapy. Bone marrow biopsy revealed hemophagocytosis. Immunological work-up for familial HLH was negative. In a desperate search for the cause of secondary HLH, an interferon-gamma release assay for TBC returned positive. However, microscopy for acid-fast bacteria as well as polymerase chain reaction for TBC were initially negative. Despite this, the child was treated with tuberculostatic therapy. TBC was finally confirmed. The child remained on extracorporeal membrane oxygenation for 28 d. Further work-up showed typical lesions of disseminated TBC. The mother was identified as the source of TBC. The boy presents with mild sequelae (fine motor skills). In infants with suspected septicemia, TBC should be considered as differential diagnosis even if the results are initially negative.

An overview of how on-call consultant paediatricians can recognise and manage severe primary immunodeficiencies

Severe primary paediatric immunodeficiency syndromes are rare and potentially fatal unless suspected, diagnosed and treated early. We provide clinical guidance and support for on-call consultant paediatricians working in secondary level hospitals on how to recognise and manage children with these conditions. Our paper addresses four conditions that risk the most severe outcomes if they are not adequately cared for during on-call periods, such as weekends: severe combined immunodeficiency, haemophagocytic lymphohistiocytosis, severe congenital neutropaenia and chronic granulomatous disease. CONCLUSION: On-call paediatricians are provided with advice on handling the most severe primary immunodeficiencies.

Complexity in unclassified auto-inflammatory disease: a case report illustrating the potential for disease arising from the allelic burden of multiple variants

BACKGROUND

Despite recent advances in the diagnosis and understanding of many autoinflammatory diseases, there are still a great number of patients with phenotypes that do not fit any clinically- and/or genetically-defined disorders.

CASE PRESENTATION

We describe a fourteen-year-old boy who presented at two and a half years of age with recurrent febrile episodes. Over the course of the disease, the episodes increased in frequency and severity, with new signs and symptoms continuing to appear. Most importantly, these included skin changes, splenomegaly and transaminitis. Only partial control of the disease was achieved with anti-IL-1 therapy. Extensive investigation showed generalized inflammation without immune deficiency, with increased levels of serum amyloid A and several pro-inflammatory cytokines including interferon-γ, as well as an increased type I interferon score. Exome sequence analysis identified P369S and R408Q variants in the MEFV innate immunity regulator, pyrin (MEFV) gene and T260 M and T320 M variants in the NLR family pyrin domain containing 12 (NLRP12) gene.

CONCLUSION

Patients with unclassified and/or unexplained autoinflammatory syndromes present diagnostic and therapeutic challenges and collectively form a substantial part of every cohort of patients with autoinflammatory diseases. Therefore, it is important to acquire their full genomic profile through whole exome and/or genome sequencing and present their cases to a broader audience, to facilitate characterization of similar patients. A critical mass of well-characterized cases will lead to improved diagnosis and informed treatment.

Fifteen-minute consultation: Recognising primary immune deficiencies in children

Children with primary immunodeficiency syndromes present with broad variation of clinical features and the consequences are often severe if not promptly recognised. Here, support is provided for the general paediatrician to recognise primary immunodeficiencies among the many children they meet in their clinical practice.

Secondary hemophagocytic syndrome after renal transplantation: two case-reports

Hemophagocytic syndrome or hemophagocytic lymphohistiocytosis (HLH) is an infrequent and underdiagnosed condition caused by an overactive immune response, resulting in blood cells phagocytosis. After kidney transplantation (KTx), HLH is usually secondary (or reactive) to infectious and neoplastic processes and has a high mortality rate. No effective treatment is available for this condition. Usual procedures include detecting and treating the pathology triggering the immune system dysregulation, other than administration of intravenous human immunoglobulin (IVIG) and high doses of steroids, and plasmapheresis. The best protocol for maintenance immunosuppressive therapy is also unknown. This article presents two cases of post-KTx reactive HLH that underwent adjuvant IVIG treatment and obtained good clinical results. Despite the high morbidity and mortality associated with reactive HLH after KTx, the early and precise diagnosis and the administration of IVIG therapy along with the treatment of the triggering disease, was an effective strategy to control HLH.

Macrophage activation syndrome due to Nocardia spp in a pediatric patient with cystic fibrosis

Nocardia spp is a gram-positive aerobic filamentous bacteria that causes pulmonary and systemic infections, especially in patients with immunosuppression or chronic lung diseases. It is rarely reported in children with cystic fibrosis. Macrophage activation syndrome is a life-threatening disease with an excessive inflammatory response usually triggered by infections. There are few reports in cystic fibrosis related to macrophage activation syndrome. Herein we report a child with cystic fibrosis who had macrophage activation syndrome due to Nocardia infection.

Measurement of iron status in chronic kidney disease

Anemia is a common complication of chronic kidney disease (CKD) in children, and dysregulation of iron homeostasis plays a central role in its pathogenesis. Optimizing iron status is a prerequisite for effective treatment of anemia. Insufficient iron can lead to inappropriate escalation of the erythropoiesis-stimulating agent (ESA) dose, which is associated with adverse outcomes. Excess iron supplementation also has negative sequelae including free radical tissue damage and increased risk of systemic infection. Notwithstanding the importance of optimizing bioavailable iron for erythropoiesis for children with advanced CKD, achieving this remains challenging for pediatric nephrologists due to the historical lack of practical and robust measures of iron status. In recent years, novel techniques have come to the fore to facilitate accurate and practical assessment of iron balance. These measures are the focus of this review, with emphasis on their relevance to the pediatric CKD population.

Cytomegalovirus reactivation in a critically ill patient: a case report

Background

The aim of this case report is to discuss diagnostic workup and clinical management of cytomegalovirus reactivation in a critically ill immunocompetent pediatric patient.

Case presentation

A 2-year-old white boy who had no medical history presented with respiratory distress and fever. His Pediatric Risk of Mortality and Pediatric Logistic Organ Dysfunction scores were 20 and 11, respectively. Our preliminary diagnosis was multiple organ dysfunction secondary to sepsis. Antibiotic treatment was started; he was intubated and artificially ventilated. Norepinephrine infusion was started. Hemophagocytic lymphohistiocytosis was diagnosed because our patient had elevated levels of serum ferritin, bicytopenia, splenomegaly, fever (> 38.5 °C), and hemophagocytosis shown in a bone marrow sample. Therapeutic plasma exchange and intravenously administered high-dose corticosteroid for hemophagocytic lymphohistiocytosis and continuous renal replacement treatment for acute renal failure were initiated. Following 5-day high-dose corticosteroid administration, therapeutic plasma exchange, and continuous renal replacement treatment, his clinical status and kidney and liver functions improved, and vasoactive requirement and ferritin levels decreased. He was extubated on the seventh day. On the tenth day of hospitalization he had a seizure and was diagnosed as having septic encephalopathy. His immune functions were found to be normal. Although his medical condition improved continuously, he had left spontaneous pneumothorax on the 21st day of admission as a complication of necrotizing pneumonia. Since pneumothorax persisted, left upper lobectomy surgery was performed on the 30th day of hospitalization. In the pathological examination of the excised lung tissue, features of cytomegalovirus infection were observed. Ganciclovir treatment was started. Serological tests indicated that our patient had cytomegalovirus reactivation. Antiviral treatment was stopped after 17 days, when cytomegalovirus deoxyribonucleic acid (DNA) polymerase chain reaction results became negative. He fully recovered and was discharged on the 50th day of admission.

Conclusions

Cytomegalovirus reactivation in critically ill patients is a prevalent problem and shown to be associated with higher mortality and morbidity. In a case of serologic detection of cytomegalovirus reactivation without any clinical sign of infection, pre-emptive treatment could be considered with assessment of risks and benefits for each patient. Antiviral therapy is highly recommended for patients who have risk factors identified.

Human Bocavirus: Can It Trigger Hemophagocytic Lymphohistiocytosis?

With improvements in molecular diagnostic methods, report of Human bocavirus (HBoV) as an etiologic agent in many studies on viral respiratory and gastrointestinal infections has been increasing. Two pediatric patients who presented with secondary hemophagocytic lymphohistiocytosis were examined for etiologic causes, including viruses. Whole bacterial and fungal cultures and viral serological studies were negative. Viral polymerase chain reaction of nasopharyngeal secretions showed HBoV. One was successfully treated with intravenous immunoglobulins, whereas the other died with multiorgan failure. Here we report 2 pediatric patients with secondary hemophagocytic lymphohistiocytosis and detection of HBoV as the sole agent, predicting an association.

H-ferritin and proinflammatory cytokines are increased in the bone marrow of patients affected by macrophage activation syndrome

Macrophage activation syndrome (MAS) is hyperinflammatory life-threatening syndrome, associated typically with high levels of serum ferritin. This is an iron storage protein including heavy (H) and light (L) subunits, categorized on their molecular weight. The H-/L subunits ratio may be different in tissues, depending on the specific tissue and pathophysiological status. In this study, we analysed the bone marrow (BM) biopsies of adult MAS patients to assess the presence of: (i) H-ferritin and L-ferritin; (ii) CD68⁺ /H-ferritin⁺ and CD68⁺ /L-ferritin⁺ ; and (iii) interleukin (IL)-1β, tumour necrosis factor (TNF) and interferon (IFN)-γ. We also explored possible correlations of these results with clinical data. H-ferritin, IL-1β, TNF and IFN-γ were increased significantly in MAS. Furthermore, an increased number of CD68⁺ /H-ferritin⁺ cells and an infiltrate of cells co-expressing H-ferritin and IL-12, suggesting an infiltrate of M1 macrophages, were observed. H-ferritin levels and CD68⁺ /H-ferritin⁺ cells were correlated with haematological involvement of the disease, serum ferritin and C-reactive protein. L-ferritin and CD68⁺ /L-ferritin⁺ cells did not correlate with these parameters. In conclusion, during MAS, H-ferritin, CD68⁺ /H-ferritin⁺ cells and proinflammatory cytokines were increased significantly in the BM inflammatory infiltrate, pointing out a possible vicious pathogenic loop. To date, H-ferritin and CD68⁺ /H-ferritin⁺ were associated significantly with haematological involvement of the disease, suggesting biomarkers assessing severity of clinical picture.