Approach to Hemophagocytic Syndromes

Comprehensive evaluation of immune dysregulation in secondary hemophagocytic lymphohistiocytosis

Host immune dysfunction plays a crucial role in the onset, progression, and outcome of hemophagocytic lymphohistiocytosis (HLH). This study aimed to comprehensively evaluate the peripheral immune profiles in patients with newly diagnosed secondary hemophagocytic lymphohistiocytosis (sHLH), and explore their predictive value for patient prognosis. A total of 77 patients with sHLH were enrolled in this study, with 31 of them experiencing mortality. Flow cytometry was used to assess the percentages, absolute numbers, and phenotypes of lymphocyte subsets. Simultaneously, cytokine levels and routine laboratory indicators were also collected. In sHLH patients, lymphocyte subset absolute numbers were significantly impaired, accompanied by T cell hyperactivation, B cell hyperactivation, and increased plasmablast proliferation. Prognostic analysis revealed that lower CD8+ T cell percentages, elevated APTT, IL-6, IL-10 levels, and increased CD4+CD28null T cell proportions were associated with poor patient outcomes. The study demonstrates dysregulation in the counts and phenotypes of lymphocyte subsets in sHLH patients. Several key factors, including IL-6, IL-10, APTT, and various T cell percentages, have potential as prognostic markers and therapeutic targets in sHLH.

Genetic background of primary and familial HLH in Qatar: registry data and population study

Background

Familial hemophagocytic lymphohistiocytosis (FHLH) is an inherited life-threatening disease. Five types are identified, with the addition of congenital immunodeficiency syndromes in which HLH is a typical manifestation. The literature on this disease is very scarce in the Middle East, with only a few scattered reports.

Methods

We report detailed demographic, clinical, and genomic data from 28 patients diagnosed with primary and familial HLH over the last decade in Qatar. An evaluation was performed of allele frequencies of deleterious variants from 12 primary and familial HLH causative genes on the Qatar Genome Programme (QGP) cohort of 14,669 Qatari individuals.

Results

The genetic diagnosis was obtained in 15 patients, and four novel mutations in Perforin 1 (PRF1), UNC13D, LYST, and RAB27A genes were found. We identified 22,945 low/high/moderate/modifier impact variants significantly enriched in the QGP in those 12 genes. The variants rs1271079313 in PRF1 and rs753966933 in RAB27A found in our patient cohort were significantly more prevalent in the QGP compared to the Genome Aggregation Database (gnomAD) database, with a high carrier frequency in the Qatari population.

Conclusions

We established the first primary and familial HLH Registry in the Gulf Region and identified novel possibly pathogenic variants present at higher frequency in the Qatari population, which could be used for screening purposes. Raising awareness about primary and familial HLH and implementing screening activities in the Qatari highly inbred population could stem into more comprehensive premarital and prenatal evaluations and faster diagnosis.

Immunopathology of and potential therapeutics for secondary hemophagocytic lymphohistiocytosis/macrophage activation syndrome: a translational perspective

Secondary hemophagocytic lymphohistiocytosis/macrophage activation syndrome (sHLH/MAS) is a life-threatening immune disorder triggered by rheumatic disease, infections, malignancies, or medications. Characterized by the presence of hemophagocytic macrophages and a fulminant cytokine storm, sHLH/MAS leads to hyperferritinemia and multiorgan failure and rapidly progresses to death. The high mortality rate and the lack of specific treatments necessitate the development of a new drug. However, the complex and largely unknown immunopathologic mechanisms of sHLH/MAS, which involve dysfunction of various immune cells, diverse etiologies, and different clinical contexts make this effort challenging. This review introduces the terminology, diagnosis, and clinical features of sHLH/MAS. From a translational perspective, this review focuses on the immunopathological mechanisms linked to various etiologies, emphasizing potential drug targets, including key molecules and signaling pathways. We also discuss immunomodulatory biologics, existing drugs under clinical evaluation, and novel therapies in clinical trials. This systematic review aims to provide insights and highlight opportunities for the development of novel sHLH/MAS therapeutics.

An Uncommon Complication of a Common Tropical Infection in a Kidney Transplant Recipient - A Case Report

Hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening condition due to extensive and uncontrolled immune activation. There is sparse literature on HLH in kidney transplant recipients. We report a case of a 27-year -old male kidney transplant recipient who presented with dengue fever and acute allograft dysfunction. Following improvement in allograft function with supportive treatment, he was found to have worsening pancytopenia with unusually high serum ferritin levels. Bone marrow aspiration performed for pancytopenia revealed hemophagocytosis. A diagnosis of HLH secondary to dengue viral infection was made based on the modified HLH diagnostic criteria (2009). He received supportive treatment and steroids and was discharged in a stable condition with normal kidney allograft functions. To our knowledge, this is the first case report of HLH secondary to dengue viral infection in a kidney allograft recipient managed successfully with timely diagnosis and appropriate treatment.

Too much of a good thing: a review of primary immune regulatory disorders

Primary immune regulatory disorders (PIRDs) are inborn errors of immunity caused by a loss in the regulatory mechanism of the inflammatory or immune response, leading to impaired immunological tolerance or an exuberant inflammatory response to various stimuli due to loss or gain of function mutations. Whilst PIRDs may feature susceptibility to recurrent, severe, or opportunistic infection in their phenotype, this group of syndromes has broadened the spectrum of disease caused by defects in immunity-related genes to include autoimmunity, autoinflammation, lymphoproliferation, malignancy, and allergy; increasing focus on PIRDs has thus redefined the classical 'primary immunodeficiency' as one aspect of an overarching group of inborn errors of immunity. The growing number of genetic defects associated with PIRDs has expanded our understanding of immune tolerance mechanisms and prompted identification of molecular targets for therapy. However, PIRDs remain difficult to recognize due to incomplete penetrance of their diverse phenotype, which may cross organ systems and present to multiple clinical specialists prior to review by an immunologist. Control of immune dysregulation with immunosuppressive therapies must be balanced against the enhanced infective risk posed by the underlying defect and accumulated end-organ damage, posing a challenge to clinicians. Whilst allogeneic hematopoietic stem cell transplantation may correct the underlying immune defect, identification of appropriate patients and timing of transplant is difficult. The relatively recent description of many PIRDs and rarity of individual genetic entities that comprise this group means data on natural history, clinical progression, and treatment are limited, and so international collaboration will be needed to better delineate phenotypes and the impact of existing and potential therapies. This review explores pathophysiology, clinical features, current therapeutic strategies for PIRDs including cellular platforms, and future directions for research.

Hemophagocytic Lymphohistiocytosis With Elevated Cytokines Related to Macrophage Activation After Liver Transplantation for Autoimmune Hepatitis: A Case Report

Hemophagocytic lymphohistiocytosis (HLH) is a rare but lethal complication of liver transplantation (LT). HLH is characterized by pathologic macrophage activation with hypercytokinemia, excessive inflammation, and tissue destruction, resulting in progressive organ dysfunction. HLH is also known as macrophage activation syndrome (MAS) when complicated by rheumatic or autoinflammatory diseases. Measuring several serum cytokines could be helpful in diagnosing HLH and MAS. Cytokines related to macrophage activation: neopterin, interleukin-18 (IL-18), and soluble tumor necrosis factor receptors (sTNF-R) I and II have not been assessed in patients with HLH complicated by LT. In this case, these cytokines were evaluated in the perioperative period of LT. The patient was a 24-year-old woman who underwent living-donor LT for acute worsening of autoimmune hepatitis. On postoperative day 12, the patient was diagnosed with HLH on the basis of the criteria. Plasma exchange, steroid pulse therapy, intravenous immunoglobulin and granulocyte-colony stimulating factor effectively inhibited progression to lethal HLH. When HLH occurred after LT, cytokine analysis showed that neopterin, IL-18, sTNFR-I, and II were elevated: cytokine storm. Of note, cytokine analysis on hospital admission also revealed elevated cytokine levels. Particularly, IL-18 levels were markedly elevated, suggesting that activation of the innate immune system was involved. These results revealed that a cytokine storm and macrophage activation developed before LT. Based on these findings, cytokine analysis related to macrophage activation may be useful for diagnosing and predicting HLH and MAS in patients with LT.

Complex considerations - Fever and pancytopenia after solid organ transplantation

This case describes a 42-year-old man who underwent kidney transplantation and developed fevers, pancytopenia, and elevated liver function tests starting on post-operative day 9. An extensive microbiologic and molecular workup was performed, ultimately leading to a diagnosis of donor-derived toxoplasmosis with associated hemophagocytic lymphohistiocytosis in the recipient. This case highlights the potential for post-transplant toxoplasmosis in high-risk mismatch (D+/R-) recipients, as well as the role of Toxoplasma-targeted prophylaxis in such patients.

Spectrum of Hemophagocytosis in Bone Marrow Aspirates: Experience from a Tertiary Care Hospital in North India

Background

Hemophagocytosis refers to the engulfment of hematopoietic cells by histiocytes. It can be seen in various conditions but is usually reported in the setting of hemophagocytic lymphohistiocytosis (HLH). Optimal interpretation of hemophagocytosis in the bone marrow in relation to the underlying disease significantly contributes to correct patient management.

Aim

The present study was done to identify the spectrum of conditions associated with hemophagocytosis in the bone marrow aspirates and grade the degree of hemophagocytosis.

Material and Methods

This retrospective observational study included all the bone marrow aspirates showing hemophagocytosis, identified over a period of 5 years (January 2015 to January 2020). Two pathologists independently reviewed bone marrow slides. Hemophagocytosis was graded as mild, moderate, or severe by observing the number of histiocytes showing hemophagocytosis per 500 nucleated cells.

Results

Eighty-eight patients showing hemophagocytosis in the bone marrow aspirate smear were included in the study. The most common cause of hemophagocytosis was infection (18%). There were 4 (5%) cases of HLH. Grade 1 (mild) hemophagocytosis was seen in 25 (29%) cases followed by Grade 2 (moderate) in 53 (60%) cases and Grade 3 (severe) in 10 (11%) cases. Fever was the most common clinical symptom present in 45 (51%) cases.

Conclusion

Hemophagocytosis in bone marrow aspirates is a common and under-reported finding. It is not only seen in cases of HLH but also in infections and other conditions. Documenting hemophagocytosis, even in the absence of fulfilled HLH criteria, is vital to explain cytopenias.

Cutaneous granuloma annulare in an adult patient with macrophage activation syndrome

Macrophage activation syndrome (MAS) is a rare but life-threatening disorder that is associated with multiple organ involvement. Here, we described cutaneous granuloma annulare in MAS. This novel histological finding is a reminder to explore the underlying mechanisms of skin involvement in MAS, which may reveal its pathogenesis.

Unusual presentation of systemic lupus erythematosus as hemophagocytic lymphohistiocytosis in a female patient: A case report

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is a rare life-threatening disorder, often resulting in the immune-mediated injury of multiple organ systems, including primary HLH and secondary HLH (sHLH). Among them, sHLH results from infections, malignant, or autoimmune conditions, which have quite poor outcomes even with aggressive management and are more common in adults.

CASE SUMMARY

We report a rare case of a 36-year-old female manifested with sHLH on background with systemic lupus erythematosus (SLE). During hospitalization, the patient was characterized by recurrent high-grade fever, petechiae and ecchymoses of abdominal skin, and pulmonary infection. Whole exon gene sequencing revealed decreased activity of natural killer cells. She received systematic treatment with Methylprednisolone, Etoposide, and anti-infective drugs. Intravenous immunoglobulin and plasmapheresis were applied when the condition was extremely acute and progressive. The patient recovered and did not present any relapse of the HLH for one year of follow-up.

CONCLUSION

The case showed sHLH, thrombotic microvascular, and infection in the whole course of the disease, which was rarely reported by now. The treatment of the patient emphasizes that early recognition and treatment of sHLH in SLE patients was of utmost importance to improve the prognosis and survival rate of patients.

Epstein-Barr virus-associated haemophagocytic lymphohistiocytosis complicated by neurological involvement in a patient with dermatomyositis: A case report and literature review

Haemophagocytic lymphohistiocytosis (HLH) is an extremely high mortality condition that can occur at any age and lacks specific diagnostic characteristics. Despite its rarity, HLH is increasingly alarming because of the high mortality rate. It is a systemic hyperinflammatory immune response syndrome associated with abnormal activation of T cells and macrophages, which may be caused by genetic mutations or acquired factors, such as infection, autoimmune condition, and malignancy. Here, we present a fatal case of Epstein-Barr virus-associated HLH complicated by neurological involvement in a patient with dermatomyositis. We describe and discuss the pathological features, classification, and effective treatment options of HLH and discuss separately the special characteristics of Epstein-Barr virus-associated HLH and dermatomyositis-associated HLH.

Hemophagocytic Lymphohistiocytosis Secondary to Chronic Lymphocytic Leukemia Progression

Hemophagocytic lymphohistiocytosis (HLH) is an acute, rare systemic hyperinflammatory disorder caused by a dysregulated immune cell function and massive cytokine release, often leading to multiple organ involvement and failure. Fever, hepatosplenomegaly, cytopenia, elevated liver enzymes, hypertriglyceridemia, and hyperferritinemia are the hallmarks of the disease. Its primary (genetic) form is typically observed in pediatric patients and its secondary, acquired form is seen in adult patients with an underlying autoimmune, malignant, or infectious disease. It is not frequently reported in patients with chronic lymphocytic leukemia (CLL) without an infectious or pharmacological trigger. We present a case of a 71-year-old patient with hemophagocytic lymphohistiocytosis due to the progression of chronic lymphocytic leukemia.

The Role of Immune Mechanisms, Inflammatory Pathways, and Macrophage Activation Syndrome in the Pathogenesis of Hemophagocytic Lymphohistiocytosis

This review article describes the pathophysiology of hemophagocytic lymphohistiocytosis (HLH). The condition is characterized by excessive stimulation of inflammatory cytokines, lymphocytes, and macrophages, leading to hyperinflammatory disorder with immune dysfunction. The main clinical and diagnostic features include fever ≥38.5°C, splenomegaly, hyperferritinemia, cytopenia, hypofibrinogenemia, hemophagocytosis on the bone marrow, low or absent of natural killer (NK) cell activity, and elevated soluble CD25. Various immunological and inflammatory mechanisms are involved in the pathogenesis of HLH. Moreover, the condition can result in multisystem organ failure, contributing to the high mortality rate in hospital settings. A thorough literature search was conducted by collecting data from multiple articles published on PubMed, Medline, and Google Scholar. The article discusses the cellular and molecular pathways that lead to HLH. Due to the high rate of morbidity and mortality, early diagnosis needs to be established. More research pertaining to molecular biology, immunology, and the genetics of HLH is needed to explore the effective management and treatment of this rare disorder.

Clinical Profile, Treatment, and Outcome of Patients with Secondary Hemophagocytic Lymphohistiocytosis in Critically Ill Patients: A Prospective Observational Study

Introduction

The objective of the study was to evaluate the clinical profile and outcome of patients with secondary hemophagocytic lymphohistiocytosis (HLH) in critically ill patients.

Materials and methods

A prospective observational study was conducted where critically ill adult patients presenting with fever and bicytopenia were evaluated according to the HLH-2004 diagnostic criteria for the presence of secondary HLH. The underlying trigger, clinical profile, treatment, and outcome of patients with HLH were analyzed.

Results

Of the 76 critically ill patients with fever and bicytopenia, 33 (43%) patients were diagnosed with HLH. The following triggers for HLH were identified: bacterial infections (23%), fungal infections (10%), viral infections (10%), parasitic infections (10%), autoimmune diseases (13%), and malignancy (8%). A total of 78% of the HLH cases received steroids, but the use of steroids was not associated with improvement in mortality.

Conclusion

There is a high prevalence of HLH in patients presenting with fever and bicytopenia in critically ill adult patients. Infections were identified as the most common trigger of HLH.

How to cite this article

Fazal F, Gupta N, Soneja M, Mitra DK, Satpathy G, Panda SK, et al. Clinical Profile, Treatment, and Outcome of Patients with Secondary Hemophagocytic Lymphohistiocytosis in Critically Ill Patients: A Prospective Observational Study. Indian J Crit Care Med 2022;26(5):564–567.

Outcome of Viral-associated Hemophagocytic Lymphohistiocytosis at a Tertiary Hospital

BACKGROUND

Little is known about viral-associated hemophagocytic lymphohistiocytosis (HLH) in Oman. This study was done to assess the epidemiology, clinical features and outcome of viral-associated HLH in our setting.

METHODS

We retrospectively reviewed children (0-18 years) managed for viral-associated HLH at the Sultan Qaboos University Hospital, Oman, over a 15-year period (2006-2020). Patients' medical records were used to describe their demographic, clinical and laboratory features, management and outcome.

RESULTS

Fifty-six children were managed for HLH at Sultan Qaboos University Hospital over the last 15 years (2006-2020) of whom a third (19; 34%) had a viral trigger. The median age at the time of diagnosis of viral-associated HLH was 83 (13-96) months. Fever, cytopenia, hyperferritinemia and evidence of hemophagocytosis in bone marrow were the most consistent findings. Most of these children had either genetic predisposition to HLH (8/19; 42%) or underlying immunodeficiency secondary to malignant conditions or chemotherapy/hematopoietic stem cell transplantation (6/19; 32%). Epstein-Barr virus (9; 47%) followed by cytomegalovirus (6; 31%) was the most common viral trigger in our setting. Treatment included antivirals (8; 42%), HLH 2004 protocol (4; 21%), rituximab (4; 21%) and hematopoietic stem cell transplantation (3; 16%). Fourteen children (74%) had full recovery.

CONCLUSIONS

In our small cohort, viral-associated HLH was more frequently encountered in children with genetic predisposition to HLH or children with underlying immunodeficiency. In addition, we found that the outcome is overall good for children who have no genetic predisposition to HLH and children with genetic predisposition who underwent hematopoietic stem cell transplantation.

A Three-Protein Panel to Support the Diagnosis of Sepsis in Children

Sepsis is a syndrome without a standard validated diagnostic test. Early recognition is crucial. Serum proteome analysis in children with sepsis may identify new biomarkers. This study aimed to find suitable blood biomarkers for an early diagnosis of sepsis. An analytical observational case-control study was carried out in a single center. Children admitted to a Pediatric Intensive Care Unit with clinical diagnosed sepsis were eligible for study. A proteomic analysis conducted by mass spectrometry was performed. Forty patients with sepsis and 24 healthy donors were recruited. Proteomics results revealed 44 proteins differentially expressed between patients and healthy controls. Six proteins were selected to be validated: lactoferrin, serum amyloid-A1 (SAA-1), complement factor B, leucine-rich alpha-2 glycoprotein (LRG1), soluble interleukin-2 alpha chain receptor (sCD25) and soluble haptoglobin−hemoglobin receptor. Our results showed that sCD25, SAA-1, and LRG1 had high levels of specificity and sensitivity, as well as an excellent area under the ROC curve (>0.9). Our study provides a serum proteomic analysis that identifies new diagnostic biomarkers in sepsis. SAA-1, sCD25 and LRG1 were able to separate septic from healthy donor, so they could be used together with other clinical and analytical features to improve sepsis diagnosis in children.

Hemophagocytic Lymphohistiocytosis Hospitalizations in Adults and Its Association With Rheumatologic Diseases: Data From Nationwide Inpatient Sample

OBJECTIVE

Hemophagocytic lymphohistiocytosis (HLH) is a rare potentially fatal multisystem inflammatory condition that is often triggered by an underlying medical condition. Epidemiologic data of HLH in adults with rheumatologic diseases are limited. The aim of our study was to characterize HLH hospitalizations in the US adult population with a special focus on patients with concomitant rheumatologic diseases.

METHODS

We conducted a medical records review of hospitalizations in the United States during 2016 and 2017 with a diagnosis of HLH. Hospitalizations were selected from the National Inpatient Sample. International Classification of Diseases, Tenth Revision codes were used to identify rheumatologic diseases. A multivariate logistic regression analysis was used to calculate adjusted odds ratios (ORadj) for the association of HLH and rheumatologic diseases.

RESULTS

Seven hundred fifty hospitalizations had a principal billing diagnosis of HLH. The median age of our study population was 47.5 years, and males made up 55% of the population. Overall mortality was 17%, and the median length of stay was 12 days. Twenty-five percent of the HLH cases had a concomitant rheumatologic diagnosis. Multivariate logistic regression analysis showed systemic lupus erythematosus (SLE) with nephritis (ORadj, 5.7), SLE without nephritis (ORadj, 9.2), adult-onset Still disease (ORadj, 338.9), and ankylosing spondylitis (ORadj, 10.7) were significantly associated with HLH.

CONCLUSIONS

This analysis represents the largest sample to date to assess HLH hospitalizations. Our study showed that SLE, adult-onset Still disease, and ankylosing spondylitis were strongly associated with HLH.

Hemphagocytic Lymphohistiocytosis Secondary to COVID-19: A Case Report

Hemophagocytic lymphohistiocytosis (HLH) is categorized into primary HLH and secondary HLH. Primary or familial HLH is an autosomal recessive disorder due to mutation in immune regulatory genes. Secondary HLH is an uncommon hyperinflammatory disease triggered by a critical illness (malignancies or viral infection) that induces an uncontrollable excessive immune response, which results in multiorgan failure. Due to the rarity of the syndrome, HLH is associated with worse outcomes. Severe coronavirus disease-19 (COVID-19) is identified as a trigger of HLH, and published literature suggests that patients with severe COVID-19 are at high risk of developing HLH. COVID-19-associated HLH is rarely reported in the literature. Herein we present a case of secondary HLH due to COVID-19 presented in the emergency department with prolonged non-resolving fever.

Clinical and laboratory characteristics of hemophagocytic lymphohistiocytosis induced by Leishmania infantum infection

Background

Visceral leishmaniasis (VL) could progress to secondary hemophagocytic lymphohistiocytosis (HLH), which is a rare but life-threatening condition with poor prognosis. So far, the clinical and laboratory characteristics of VL associated HLH have not been well elucidated.

Method and findings

In this study, we retrospectively analyzed the clinical and laboratory profiles between 17 patients with VL associated HLH and 27 patients with VL alone admitted at the Beijing Friendship Hospital, Capital Medical University from May 2016 to March 2021. In addition to the identification of Leishmania infection, hemophagocytosis was identified in bone marrow in the most cases of VL associated HLH (15/17). The patients with VL associated HLH had higher chances of bleeding, hepatomegaly, thrombocytopenia, hypertriglyceridemia, hyperferritinemia, hypofibrinogenemia, elevated secretion of soluble IL-2 receptor or lower NK cell activity compared to patients with VL only. Furthermore, patients with VL associated HLH had higher inflammation status associated with higher levels of Th1 (TNF-α, IFN-γ, IL-1beta, IL-6, IL-8, IL-12p70), Th2 (IL-4) and Th17 cytokines (IL-17, IL-23) in the peripheral blood, and higher parasite load (qPCR and parasite culture). All 27 VL cases were totally recovered after being treated with Sodium Stibogluconate, five of the 17 patients with VL associated HLH died even after timely treatment with anti-parasite and immunosuppressive chemotherapy.

Conclusion

Without appropriate treatment, visceral leishmaniosis could develop to secondary HLH. The parasite culturing and qPCR detection of bone marrow samples facilitates the diagnosis of VL associated HLH in addition to other findings of HLH. Prompt treatment with anti-Leishmania and immunosuppressive chemotherapy is critical to reduce the mortality of VL associated HLH.

Hemophagocytic lymphohistiocytosis (HLH) is a rare but life-threatening syndrome characterized by pro-inflammatory cytokine secretion, hyperinflammatory and multiple organ damages. Visceral leishmaniasis (VL) is a well-known cause of infection associated HLH and result in fatal consequence. However, it is not well characterized for the clinical and laboratory features of the visceral leishmaniasis associated HLH. In this study, we presented that, compared to the VL alone, patients with VL associated HLH had higher chances of bleeding, hepatomegaly, thrombocytopenia, hypertriglyceridemia, hyperferritinemia, hypofibrinogenemia, elevated secretion of soluble IL-2 receptor or lower NK cell activity. Moreover, patients with VL associated HLH also had higher levels of Th1, Th2 and Th17 cytokines in the sera and had higher parasite load in the bone marrow specimen. More cases with VL associated HLH had hepatosplenomegaly with iron overload in the magnetic resonance imaging. In the therapeutic strategy, besides the anti-Leishmania treatment, anti-inflammatory therapy to reduce cytokine storm and excessive immune responses facilitated the remission in the VL associated HLH cases.

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.

Griscelli Syndrome in a seven years old girl

In this study, a case of Griscelli Syndrome (GS) in a 7 years old girl was reported. The patient initially presented with fever and pancytopenia in laboratory results; after ruling out the malignancies, she went under treatment with the diagnosis of infectious disease and was discharged after two weeks. Nevertheless, ten days after discharge, she developed new symptoms. Due to patient symptoms and general appearance, microscopic analysis of her hair shaft was done, and the abnormal distribution of pigments in the shaft was observed, indicating GS.

Reactions Related to CAR-T Cell Therapy

The application of chimeric antigen receptor (CAR) T-cell therapy as a tumor immunotherapy has received great interest in recent years. This therapeutic approach has been used to treat hematological malignancies solid tumors. However, it is associated with adverse reactions such as, cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), off-target effects, anaphylaxis, infections associated with CAR-T-cell infusion (CTI), tumor lysis syndrome (TLS), B-cell dysplasia, hemophagocytic lymphohistiocytosis (HLH)/macrophage activation syndrome (MAS) and coagulation disorders. These adverse reactions can be life-threatening, and thus they should be identified early and treated effectively. In this paper, we review the adverse reactions associated with CAR-T cells, the mechanisms driving such adverse reactions, and strategies to subvert them. This review will provide important reference data to guide clinical application of CAR-T cell therapy.

Secondary Hemophagocytic Lymphohistiocytosis in a Young Hispanic Adult

Hemophagocytic lymphohistiocytosis (HLH) is a disease caused by a severe immune system reaction that involves an overwhelming inflammatory response with overproduction of cytokines and hemophagocytosis. HLH is classified as primary HLH or familial HLH (PHLH or FHLH) and secondary HLH. PHLH is due to mutations in several genes that regulate immune cells, while secondary HLH is triggered by a severe illness (viral infections or malignancies) that induce an excessive immune response that is difficult to control. We present a case of a young Hispanic adult female with a medical history of diabetes mellitus type 1 and hepatitis E that was diagnosed with HLH secondary to lymphoma caused by Epstein Barr virus infection. The patient was started on broad-spectrum antibiotics and steroid therapy; however, the patient succumbed to the disease. HLH is associated with high mortality, mainly because it is not a very common entity and patients usually present critically ill and deteriorate very fast. Immunosuppression and treatment of the underlying disorder is the target of the treatment of HLH, however, the prognosis remains poor.

Cytokine storm syndrome in coronavirus disease 2019: A narrative review

Cytokine storm syndrome (CSS) is a critical clinical condition induced by a cascade of cytokine activation, characterized by overwhelming systemic inflammation, hyperferritinaemia, haemodynamic instability and multiple organ failure (MOF). At the end of 2019, the disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in Wuhan, China, and rapidly developed into a global pandemic. More and more evidence shows that there is a dramatic increase of inflammatory cytokines in patients with COVID-19, suggesting the existence of cytokine storm in some critical illness patients. Here, we summarize the pathogenesis, clinical manifestation of CSS, and highlight the current understanding about the recognition and potential therapeutic options of CSS in COVID-19.

Diagnosis and management of immune-related adverse effects of immune checkpoint therapy in the emergency department

Rapid advances in cancer immunotherapy using immune checkpoint inhibitors have led to significantly improved survival. Rapid identification of the toxicity syndromes associated with these therapeutic agents is very important for emergency physicians because the population of patients diagnosed with cancer is increasing and cancer therapies including immune checkpoint inhibitors have become the first-line treatment for more and more types of cancer. The emergency medicine literature lags behind rapid advances in oncology, and oncology guidelines for rapid recognition and management of these emerging toxicity syndromes are not familiar to emergency physicians. In this review article, we discuss the clinical presentation and management of immune-related adverse effects during the critical first hours of emergency care. We also suggest a workflow for the recognition and treatment of emergencies arising from serious immune-related adverse effects, including but not limited to colitis, adrenal crisis, myocarditis, pneumonitis, myasthenic crisis, diabetic ketoacidosis, bullous pemphigus, and hemophagocytic lymphohistiocytosis. Rapid advances in cancer therapy are bringing new diagnostic and therapeutic challenges to emergency providers, and therefore it is crucial to raise awareness and provide guidelines for the management of new treatment-related toxicities.

Higher Incidence of B Cell Malignancies in Primary Immunodeficiencies: A Combination of Intrinsic Genomic Instability and Exocytosis Defects at the Immunological Synapse

Congenital defects of the immune system called primary immunodeficiency disorders (PID) describe a group of diseases characterized by a decrease, an absence, or a malfunction of at least one part of the immune system. As a result, PID patients are more prone to develop life-threatening complications, including cancer. PID currently include over 400 different disorders, however, the variety of PID-related cancers is narrow. We discuss here reasons for this clinical phenotype. Namely, PID can lead to cell intrinsic failure to control cell transformation, failure to activate tumor surveillance by cytotoxic cells or both. As the most frequent tumors seen among PID patients stem from faulty lymphocyte development leading to leukemia and lymphoma, we focus on the extensive genomic alterations needed to create the vast diversity of B and T lymphocytes with potential to recognize any pathogen and why defects in these processes lead to malignancies in the immunodeficient environment of PID patients. In the second part of the review, we discuss PID affecting tumor surveillance and especially membrane trafficking defects caused by altered exocytosis and regulation of the actin cytoskeleton. As an impairment of these membrane trafficking pathways often results in dysfunctional effector immune cells, tumor cell immune evasion is elevated in PID. By considering new anti-cancer treatment concepts, such as transfer of genetically engineered immune cells, restoration of anti-tumor immunity in PID patients could be an approach to complement standard therapies.

Overlap between hemophagocytic lymphohistiocytosis and drug reaction and eosinophilia with systemic symptoms: a review

Drug reaction and eosinophilia with systemic symptoms (DRESS), also known as drug-induced hypersensitivity syndrome (DIHS), shares features with hemophagocytic lymphohistiocytosis (HLH), most notably fever, rash, and internal organ involvement. However, there is increasing recognition of drug-induced (secondary) HLH and biopsy-proven hemophagocytosis in DRESS, suggesting that HLH and DRESS not only overlap but also may be diseases on the same spectrum of immune dysfunction. To characterize existing literature on HLH/DRESS overlap, we queried the PubMed/MEDLINE database for 23 cases of HLH-DRESS codiagnosis. Average time-to-onset of rash after exposure to inciting drug was 2.7 weeks. Fourteen cases (61%) clinically worsened despite initial therapy, prompting a workup with diagnosis of HLH on average 2.3 weeks after diagnosing DRESS. Nine cases met HLH diagnostic criteria and had a RegiSCAR score ≥4. Nine cases met one set of criteria with a presentation suggestive of the other. Five cases met neither criteria. A patient presenting with fever, generalized rash, bicytopenia, and internal organ involvement after drug exposure was most predictive of meeting diagnostic criteria for both HLH and DRESS. Treatment was highly variable, although most initiated systemic corticosteroids with/without IVIG, plasmapheresis, or etoposide. Patients with poor outcomes in this review were treated using steroid monotherapy and had viral reactivation. Dermatologists should consider the possibility of HLH in any patient presenting with fever, rash, internal organ involvement, and cytopenia. Additional studies will be necessary to further characterize HLH and DRESS overlap and determine optimal management.

Effect of different conditioning regimens on survival and engraftment for children with hemophagocytic lymphohistiocytosis undergoing allogeneic hematopoeitic stem cell transplantation: A single institution experience

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH), a rare hyperinflammatory immuneregulatory disorder, is a challenge in hematopoietic stem cell transplantation (HSCT) because of the high rate of mixed chimerism, relapse, and graft failure (GF) unless intensive myeloablative regimens are used. However, historically conventional myeloablative regimens (conv MA) are associated with high toxicity and mortality.

PROCEDURE

We retrospectively compared transplant outcomes between three preparative regimens of varying intensities: Conv MA (n = 15), reduced-intensity conditioning (RIC, n = 12), and a treosulfan-based reduced-toxicity conditioning (RTC, n = 9).

RESULTS

Patients in the RIC cohort had a higher incidence of mixed donor chimerism and five patients (42%) developed secondary GF (P = .002) compared to the other two regimens. There was a higher incidence of veno-occlusive disease and intensive care unit (ICU) admissions in the Conv MA cohort. With the RTC regimen, there was a similar 2-year overall survival (89, 73, and 83%; P = .87), but improved compound EFS (lack of relapse, GF, second transplant or additional donor cell infusions, or death; 89, 73, and 42%, P = .041) in RTC, Conv MA, and RIC regimen, respectively.

CONCLUSIONS

The intensity of the preparative regimen has a significant impact on outcome of HSCT for HLH. The newly described treosulfan-based RTC provides for a stable graft with a reasonable toxicity profile.

Dengue Hemorrhagic Fever Complicated With Hemophagocytic Lymphohistiocytosis in an Adult With Diabetic Ketoacidosis

Dengue infection can cause a wide spectrum of presentations extending from simple self-limiting febrile illness to severe dengue, including dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Dengue associated hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening condition characterized by the uncontrolled activation of macrophages and T cells, eliciting clusters of symptoms and signs and abnormal biochemical parameters. Herein we report a 28-year-old Sri Lankan female with no past medical history who presented with dengue hemorrhagic fever and diabetic ketoacidosis complicated with hemophagocytic lymphohistiocytosis. She was treated with a three-day course of intravenous methylprednisolone in addition to standard care for diabetic ketoacidosis and dengue hemorrhagic fever. She made an uneventful recovery.

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 Lymphohistiocytosis: A Rare Complication of an Ultrarare Lysosomal Storage Disease

Hemophagocytic lymphohistiocytosis (HLH) is a rare and life-threatening hyperinflammatory condition that may be triggered by infections, autoimmune and immunologic disorders, malignancies, and metabolic diseases. Early and accurate diagnosis of HLH and its underlying cause is of paramount importance for proper management and prognosis. We report the case of a Tunisian 21-month-old girl who initially presented clinical features of HLH related to a lysosomal acid lipase deficiency. The genetic sequence analysis of the LIPA gene revealed a never described homozygous mutation c.966G>C (p.Gln322His). The parents were heterozygous for this mutation. Enzyme replacement therapy was not provided for the patient. She received etoposide, corticosteroids, and cyclosporine for the HLH. She is waiting for hematopoietic stem cell transplantation. To the best of our knowledge, this is the second Tunisian case of secondary HLH complicating lysosomal acid lipase deficiency related to a new homozygous mutation: c.966G>C (p.Gln322His).

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.

Epstein-Barr Virus Infection-associated Hemophagocytic Lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a rare and life-threatening syndrome characterized by uncontrolled immune activation. There is an aberrant activation of lym-phocytes and macrophages that results in hypercytokinemia. We aim to describe a case of secondary HLH due to primary Epstein-Barr virus (EBV) infection. A Hispanic 28-year-old man presented with sore throat and fatigue for one week. He was diagnosed with mononucleosis and discharged and was treated according to the currently available treatment. HLH is treated by diminishing the inflammation by myelosuppressive and immunosuppressive therapy. EBV infection-associated HLH is a rare disease with high mortality. It is crucial to think about it when facing a patient with fever, cytopenia, hepatosplenomegaly, and high levels of ferritin. Despite medical treatment, the patient died from multiorgan failure.

Diagnosis and Management of Secondary HLH/MAS Following HSCT and CAR-T Cell Therapy in Adults; A Review of the Literature and a Survey of Practice Within EBMT Centres on Behalf of the Autoimmune Diseases Working Party (ADWP) and Transplant Complications Working Party (TCWP)

Introduction: Secondary haemophagocytic lymphohistiocytosis (sHLH) or Macrophage Activation Syndrome (MAS) is a life-threatening hyperinflammatory syndrome that can occur in patients with severe infections, malignancy or autoimmune diseases. It is also a rare complication of haematopoetic stem cell transplantation (HSCT), with a high mortality. It may be associated with graft vs. host disease in the allogeneic HSCT setting. It is also reported following CAR-T cell therapy, but differentiation from cytokine release syndrome (CRS) is challenging. Here, we summarise the literature and present results of a survey of current awareness and practice in EBMT-affiliated centres of sHLH/MAS following HSCT and CAR-T cell therapy. Methods: An online questionnaire was sent to the principal investigators of all EBMT member transplant centres treating adult patients (18 years and over) inviting them to provide information regarding: number of cases of sHLH/MAS seen in their centre over 3 years (2016-2018 inclusive); screening strategies and use of existing diagnostic/classification criteria and treatment protocols. Results: 114/472 centres from 24 different countries responded (24%). We report estimated rates of sHLH/MAS of 1.09% (95% CI = 0.89-1.30) following allogeneic HSCT, 0.15% (95% CI = 0.09-5.89) following autologous HSCT and 3.48% (95% CI = 0.95-6.01) following CAR-T cell therapy. A majority of centres (70%) did not use a standard screening protocol. Serum ferritin was the most commonly used screening marker at 78% of centres, followed by soluble IL-2 receptor (24%), triglycerides (15%), and fibrinogen (11%). There was significant variation in definition of "clinically significant" serum ferritin levels ranging from 500 to 10,000 μg/mL. The most commonly used criteria to support diagnosis were HLH-2004 (43%) and the H score (15%). Eighty percent of responders reported using no standard management protocol, but reported using combinations of corticosteroids, chemotherapeutic agents, cytokine blockade, and monoclonal antibodies. Conclusions: There is a remarkable lack of consistency between EBMT centres in the approach to screening, diagnosis and management. Further research in this field is needed to raise awareness of and inform harmonised, evidence-based approaches to the recognition and treatment of sHLH/MAS following HSCT/CAR-T cell therapy.

Hemophagocytic syndrome with severe sepsis caused by Capnocytophaga canimorsus

Capnocytophaga canimorsus, commonly transmitted by dog bites, can cause severe sepsis, and the mortality rate is very high. We experienced a case of hemophagocytic lymphohistiocytosis (HLH) complicated by severe sepsis caused by C. canimorsus. A 58-year-old man with no remarkable medical history was admitted to another hospital with fever and mild consciousness disorder developed 3 days after being bitten by his dog. The next day, the patient developed disseminated intravascular coagulation and shock and was transferred to our emergency medical center. Blood tests showed hyperferritinemia and cytopenia, and bone marrow aspiration was performed. As a result, we diagnosed severe sepsis and HLH. Once antibiotic and steroid therapy was started, the patient's infection and cytopenia improved. Unfortunately, the patient's fingers and toes required amputation, but his life was saved, and he was discharged from hospital. Because HLH may be hidden in such cases, it may be necessary to measure serum ferritin and perform bone marrow aspiration if hyperferritinemia is suspected.

Macrophage activation syndrome in adults: recent advances in pathophysiology, diagnosis and treatment

Haemophagocytic lymphohistiocytosis (HLH) is a hyperinflammatory syndrome, which if not promptly treated, can lead rapidly to critical illness and death. HLH is termed macrophage activation syndrome (MAS) when associated with rheumatic disease (where it is best characterized in systemic JIA) and secondary HLH (sHLH) when associated with other triggers including malignancy and infection. MAS/sHLH is rare and coupled with its mimicry of other conditions, is underrecognized. These inherent challenges can lead to diagnostic and management challenges in multiple medical specialties including haematology, infectious diseases, critical care and rheumatology. In this review we highlight the pathogenesis of MAS/sHLH including its underlying triggers, key clinical features and diagnostic challenges, prognostic factors and current treatments in adults.

Unusual Presentation of Hemophagocytic Lymphohistiocytosis in a Kidney Transplant Patient

We are presenting a case of a middle-aged woman with history of remote kidney transplantation who had multiple admissions for septic shock-like picture, recurrent fever, and hypotension. Her shock manifestation would resolve after stress dose steroid administration and less than 24 hours of vasopressor administration. Initially, extensive workup was performed without revealing etiology. Eventually, a bone marrow biopsy was carried out leading to the diagnosis of hemophagocytic lymphohistiocytosis, most likely related to recent cytomegalovirus infection.

Síndrome hemofagocitico

En este artículo los autores realizan una revisión de las manifestaciones clínicas, patología, diagnóstico y tratamiento de pacientes con síndrome hemofagocítico.

Hemophagocytic lymphohistiocytosis is a sign of poor outcome in pediatric Epstein-Barr virus-associated post-transplant lymphoproliferative disease after allogeneic hematopoietic stem cell transplantation

EBV-related PTLD developing after HSCT is a potentially life-threatening disease. HLH is uncommon after allogeneic HSCT. Data on outcome of patients with PTLD and concomitant HLH after allogeneic HSCT are limited. In this retrospective study, we collected demographic, clinical, laboratory, and outcome data for 408 patients who underwent allogeneic HSCT from 2006 to 2015. Graft source included CB (n = 135; 33.1%), PBSCs (n = 34; 8.3%), and BM (n = 239; 58.6%). Eight out of 408 patients (2%) developed EBV-PTLD with a median age at HSCT of 5.9 years (range: 2.3-17.3). All eight patients received ATG as part of the conditioning regimen. Graft source was PBSC in three patients (37.5%), BM in four patients (50%), and CB in one patient (12.5%). Donors were matched unrelated in five patients (62.5%) and matched sibling in three patients (37.5%). Seven out of eight patients developed EBV-PTLD within the first 100-day post-HSCT. Lymph node biopsy revealed early lesions in three patients, polymorphic in three patients, and monomorphic PTLD in two patients. Three patients (37.5%) died within 1 month of EBV-PTLD diagnosis. All deceased patients developed HLH manifestations with two of them meeting HLH diagnostic criteria and one having an incomplete workup. PTLD after allogeneic HSCT with manifestations of HLH is associated with high mortality. Early identification and treatment of EBV-PTLD seems imperative to control the disease, especially if signs of HLH are evolving.

Critical Care Management: Sepsis and Disseminated and Local Infections

Local and systemic infections are a significant cause of morbidity and mortality among immunocompromised children, including but not limited to patients with hematologic and solid malignancies, congenital or acquired immunodeficiencies, or hematopoietic cell or solid organ transplantation patients. Progression to septic shock can be rapid and profound and thus requires specific diagnostic and treatment approaches. This chapter will discuss the diagnosis and the initial hemodynamic management strategies of septic shock in immunocompromised children, including strategies to improve oxygen delivery, reduce metabolic demand, and monitor hemodynamic response to resuscitation. This chapter also discusses strategies to reverse septic shock pathobiology, including the use of both empiric and targeted anti-infective strategies and pharmacologic and cell therapy-based immunomodulation. Specific consideration is also paid to the management of high-risk subpopulations and the care of septic shock patients with resolving injury.

A multicenter study of patients with multisystem Langerhans cell histiocytosis who develop secondary hemophagocytic lymphohistiocytosis

BACKGROUND

Langerhans cell histiocytosis (LCH) is a rare myeloid neoplasm characterized by the presence of abnormal CD1a-positive (CD1a⁺ )/CD207⁺ histiocytes. Hemophagocytic lymphohistiocytosis (HLH) represents a spectrum of hyperinflammatory syndromes typified by the dysregulated activation of the innate and adaptive immune systems. Patients with LCH, particularly those with multisystem (MS) involvement, can develop severe hyperinflammation mimicking that observed in HLH. Nevertheless, to the authors' knowledge, little is known regarding the prevalence, timing, risk factors for development, and outcomes of children and young adults who develop HLH within the context of MS-LCH (hereafter referred to LCH-associated HLH).

METHODS

To gain further insights, the authors conducted a retrospective, multicenter study and collected data regarding all patients diagnosed with MS-LCH between 2000 and 2015.

RESULTS

Of 384 patients with MS-LCH, 32 were reported by their primary providers to have met the diagnostic criteria for HLH, yielding an estimated 2-year cumulative incidence of 9.3% ± 1.6%. The majority of patients developed HLH at or after the diagnosis of MS-LCH, and nearly one-third (31%) had evidence of an intercurrent infection. Patient age <2 years at the time of diagnosis of LCH; female sex; LCH involvement of the liver, spleen, and hematopoietic system; and a lack of bone involvement each were found to be independently associated with an increased risk of LCH-associated HLH. Patients with MS-LCH who met the criteria for HLH had significantly poorer 5-year survival compared with patients with MS-LCH who did not meet the criteria for HLH (69% vs 97%; P < .0001).

CONCLUSIONS

Given its inferior prognosis, further efforts are warranted to enhance the recognition and optimize the treatment of patients with LCH-associated HLH.

Different Presentations of Patients with Transcobalamin II Deficiency: A Single-Center Experience from Turkey

Objective:

Transcobalamin II deficiency is a rare autosomal recessive disease characterized by decreased cobalamin availability, which in turn causes accumulation of homocysteine and methylmalonic acid. The presenting clinical features are failure to thrive, diarrhea, megaloblastic anemia, pancytopenia, neurologic abnormalities, and also recurrent infections due to immune abnormalities in early infancy.

Materials and Methods:

Here, we report the clinical and laboratory features of six children with transcobalamin II deficiency who were all molecularly confirmed.

Results:

The patients were admitted between 1 and 7 months of age with anemia or pancytopenia. Unexpectedly, one patient had a serum vitamin B12 level lower than the normal range and another one had nonsignificantly elevated serum homocysteine levels. Four patients had lymphopenia, four had neutropenia and three also had hypogammaglobulinemia. Suggesting the consideration of transcobalamin II deficiency in the differential diagnosis of immune deficiency. Hemophagocytic lymphohistiocytosis was also detected in one patient. Furthermore, two patients had vacuolization in the myeloid lineage in bone marrow aspiration, which may be an additional finding of transcobalamin II deficiency. The hematological abnormalities in all patients resolved after parenteral cobalamin treatment. In follow-up, two patients showed neurological impairments such as impaired speech and walking. Among our six patients who were all molecularly confirmed, two had the mutation that was reported in transcobalamin II-deficient patients of Turkish ancestry. Also, a novel TCN2 gene mutation was detected in one of the remaining patients.

Conclusion:

Transcobalamin II deficiency should be considered in the differential diagnosis of infants with immunological abnormalities as well as cytopenia and neurological dysfunction. Early recognition of this rare condition and initiation of adequate treatment is critical for control of the disease and better prognosis.

Fever in a returning traveller: visceral leishmaniasis triggering haemophagocytic lymphohistiocytosis

We present the case of a 23-year-old student admitted with fever, night sweats and splenomegaly. These non-specific signs and symptoms posed a diagnostic challenge which was further complicated by a history of recent foreign travel. The range of potential diagnoses required a variety of investigations in order to reach the final diagnosis. The incidental finding of an incompetent bicuspid aortic valve and an inflamed gallbladder further clouded the diagnostic process. Despite treatment with broad spectrum antibiotics, the patient continued to deteriorate. Serological testing finally provided a diagnosis of visceral leishmaniasis. The patient subsequently developed haemophagocytic lymphohistiocytosis, a life-threatening immune hyperactivity state that very rarely complicates leishmaniasis infection. With the use of amphotericin B and high-dose steroids, the patient made an excellent recovery.