Approach to Hemophagocytic Syndromes

Hemophagocytic lymphohistiocytosis: review of etiologies and management

Hemophagocytic lymphohistiocytosis (HLH) covers a wide array of related life-threatening conditions featuring ineffective immunity characterized by an uncontrolled hyperinflammatory response. HLH is often triggered by infection. Familial forms result from genetic defects in natural killer cells and cytotoxic T-cells, typically affecting perforin and intracellular vesicles. HLH is likely under-recognized, which contributes to its high morbidity and mortality. Early recognition is crucial for any reasonable attempt at curative therapy to be made. Current treatment regimens include immunosuppression, immune modulation, chemotherapy, and biological response modification, followed by hematopoietic stem-cell transplant (bone marrow transplant). A number of recent studies have contributed to the understanding of HLH pathophysiology, leading to alternate treatment options; however, much work remains to raise awareness and improve the high morbidity and mortality of these complex conditions.

Risk for complications in patients with hemophagocytic lymphohistiocytosis who undergo hematopoietic stem cell transplantation: myeloablative versus reduced-intensity conditioning regimens

Allogeneic hematopoietic stem cell transplantation (HSCT) is the only curative option for patients with primary hemophagocytic lymphohistiocytosis (HLH) and for patients with secondary HLH who fail to respond to therapy. Advances in HSCT and supportive care measures have resulted in improved patient outcomes and decreased treatment-related mortality. Despite the overall improvement in outcome, HLH patients who undergo HSCT using myeloablative conditioning regimens are still at significant risk for complications. The HLH-94 study conducted by the Histiocyte Society reported a 30% TRM with increased pulmonary and hepatic complications. Recently, the use of reduced-intensity conditioning (RIC) regimens has shown favorable outcomes when compared to conventional HSCT and lower rate of acute complications. In this review we compare the potential complications of myeloablative and RIC regimens for HSCT in HLH patients.

Haemophagocytic lymphohistiocytosis with lung cavity and lytic bone lesion in a 45 day infant

Haemophagocytic lymphohistiocytosis (HLH) is a potentially fatal, hyper inflammatory condition which is caused by a highly stimulated but ineffective immune response. We are presenting here, a case of HLH which occurred in a 45 day infant. Presence of lung cavity and a lytic bone lesion in the skull, as was seen in this case, have not been reported in HLH in the literature. This raises a possibility of a simultaneous occurrence of HLH and Langerhans cell histiocytosis. In a child who presents with septicaemia but does not respond to treatment, the possibility of HLH needs to be considered.

Prognostic factors and outcomes of adults with hemophagocytic lymphohistiocytosis

OBJECTIVE

To describe the prognostic factors and outcomes of adults with hemophagocytic lymphohistiocytosis (HLH), a rare disorder caused by pathologic activation of the immune system.

PATIENTS AND METHODS

The study population consisted of a consecutive cohort of adult (age ≥18 years) patients treated at Mayo Clinic in Rochester, Minnesota, from January 1, 1996, through December 31, 2011, in whom a diagnosis of HLH was suspected and subsequently confirmed by retrospective review using the HLH-04 diagnostic criteria.

RESULTS

Of 250 adult patients suspected of having HLH, 62 met the HLH-04 diagnostic criteria and were included in the final analysis. The median age was 49 years (range, 18-87 years), and 42 (68%) were male. The underlying cause of HLH was malignant tumor in 32 patients (52%), infection in 21 patients (34%), autoimmune disorder in 5 patients (8%), and idiopathic disease in 4 patients (6%). After a median follow-up of 42 months, 41 patients (66%) had died. The median overall survival of the entire cohort was 2.1 months. The median overall survival of patients with tumor-associated HLH was 1.4 months compared with 22.8 months for patients with non-tumor-associated HLH (P=.01). The presence of a malignant tumor and hypoalbuminemia were significant predictors of inferior survival on multivariate analysis.

CONCLUSION

In this large series of adults with secondary HLH treated at a single tertiary care center, patients with low serum albumin levels and tumor-associated HLH had a markedly worse survival. Hemophagocytic lymphohistiocytosis remains elusive and challenging to clinicians who must maintain a high index of suspicion. The recent discovery of several novel diagnostic and therapeutic modalities may improve outcomes of adult patients with HLH.

Late Onset Combined Immunodeficiency Presenting with Recurrent Pneumocystis jiroveci Pneumonia

Late onset combined immunodeficiency (LOCID) is a recently described variant of common variable immunodeficiency (CVID), involving adult patients presenting with opportunistic infections and/or low CD4+ lymphocyte counts. A 36-year-old male with unremarkable past medical history presented with fever, respiratory failure, and lymphocytopenia. He was found to have Pneumocystis jiroveci pneumonia (PJP), subsequently complicated by recurrent hospital-acquired Pseudomonas aeruginosa pneumonia and immune reconstitution phenomena, attributed to restoration of immunoglobulin levels. Clinicians should be aware of LOCID, which could be confused with HIV infection/AIDS or idiopathic CD4 lymphocytopenia. In the English bibliography there is only one case report, where PJP was the initial presentation of CVID (that case would probably be classified as LOCID). Phenomena of immune reconstitution are described in various settings, including primary immunodeficiency, manifesting as temporary clinical and radiologic deterioration and leading to misperceptions of therapeutic failure and/or presence of alternative/additional diagnoses.

Familial hemophagocytic lymphohistiocytosis type 3 diagnosed at school age: a case report

Familial hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening condition characterized by immune hyperactivation and clinical signs of extreme inflammation. We describe a 7-year-old male who presented with fever resistant to antibiotic therapy, pancytopenia, splenomegaly, hypertriglyceridemia, and hyperferritinemia. Bone marrow aspirate showed hemophagocytosis. Epstein-Barr virus genome was positive in blood. Functional screening showed reduced capacity of cytotoxic degranulation. Mutation analysis of the FHL-related genes revealed compound heterozygous for UNC13D mutations: c. 753+1G>T, and the novel c.544C>T (p.P182S). Patients with a clinical presentation of HLH, even if older than typically seen, should be screened for familial HLH by mutation analysis.

Griscelli syndrome type 2: a novel mutation in RAB27A gene with different clinical features in 2 siblings: a diagnostic conundrum

Griscelli syndrome type 2 (GS2) is a rare autosomal recessive disease caused by mutations in the RAB27A gene. It is characterized by cutaneous hypopigmentation, immunodeficiency, and hemophagocytic lymphohistiocytosis. We describe 2 brothers who had GS2 with clinically diverse manifestations. The elder brother presented with a purely neurological picture, whereas the younger one presented with fever, pancytopenia, hepatosplenomegaly, and erythema nodosum. Considering that cutaneous hypopigmentation was a common feature between the brothers, genetic analysis for Griscelli syndrome was performed. As the elder sibling had died, mutation analysis was only performed on the younger sibling, which revealed a novel homozygous mutation in the RAB27A gene on chromosome 15 showing a single-base substitution (c.136T>A p.F46I). Both parents were heterozygous for the same mutation. This confirmed the diagnosis of GS2 in the accelerated phase in both siblings. The atypical features of GS2 in these cases are a novel mutation, isolated neurological involvement in one sibling, association with erythema nodosum, and 2 distinct clinical presentations in siblings with the same genetic mutation.

A novel mutation of the transcobalamin II gene in an infant presenting with hemophagocytic lymphohistiocytosis

Transcobalamin II (TC II) deficiency is a rare disorder of cobalamin (CBL, vitamin B12) metabolism that occurs due to mutations in transcobalamin gene (TCN2). Hemophagocytic lymphohistiocytosis (HLH) in contrast is a syndrome characterized by uncontrolled immune response with hyperinflammation. A 2-month-old male baby was admitted with complaints of fever, cough, diarrhea, and respiratory distress. The parents were first cousins. The baby exhibited five of the eight diagnostic criteria for HLH-2004 and was diagnosed as HLH. A second bone marrow aspiration demonstrated megaloblastic changes in the erythroid series. The patient's vitamin B12 level was normal; however, hyperhomocysteinemia was present. A genetic deficiency of TC II was suspected. The patient and his parents were tested for TCN2 mutation. He had a homozygote mutation that was not included in Human 'Gene Mutation Database Cardiff'. The patient was treated with intramuscular vitamin B12, which was followed by improvement in both clinical and laboratory findings. He was 12 months old at the time of this report, with normal physical and neuromotor development. In this case presenting with the clinical and laboratory findings of HLH, TC II deficiency was diagnosed. A new mutation was found that was not reported before. Potential causative mechanisms of HLH induced by defects of cobalamin synthesis merit further investigation.

Secondary Hemophagocytic Syndrome Associated with Richter's Transformation in Chronic Lymphocytic Leukemia

Hemophagocytic syndrome (HPS) is an extremely rare condition arising from the overactivation of one's own immune system. It results in excessive inflammation and tissue destruction. Prompt initiation of treatment is warranted in either scenario in order to decrease mortality. Most cases are triggered by infectious agents, malignancy, or drugs. We describe the first case of a CLL patient presenting with HPS due to acquisition of EBV-related large cell lymphoma in the setting of profound immunodeficiency.

Hemophagocytic Syndrome and Critical Illness: New Insights into Diagnosis and Management

Hemophagocytic lymphohistiocytosis (HLH) comprises a heterogeneous group of diseases that are characterized by a hyperinflammatory state due to uncontrolled T cell, macrophage, and histiocyte activation, accompanied by excessive cytokine production. This rare condition is almost uniformly fatal unless promptly recognized and treated. Much progress has been made in the last two decades in our understanding of the mechanisms underlying familial, and to a lesser extent, acquired cases of HLH. Recurrent mutations in more than 10 different genes have now been identified, involving biological pathways converging on intracellular vesicle trafficking and cytolytic granule exocytosis. Mechanisms underlying the majority of patients with acquired HLH, however, remain elusive, hampering both diagnostic evaluation and therapeutic management of these patients. Given that the majority of intensive care unit (ICU) patients with sepsis or multiorgan failure share many features of HLH, it is especially critical for pediatric and adult intensivists to be able to recognize patients with bona fide HLH and initiate treatment without delay. In this article, we review our current understanding of the pathophysiology, clinical testing, diagnosis, and treatment of patients with HLH, especially as it pertains to the care of critically ill patients in pediatric and medical ICUs.

Hemophagocytic lymphohistiocytosis secondary to Mycoplasma pneumoniae infection without pneumonia

Mycoplasma pneumoniae typically causes respiratory tract infections, including pneumonia. We herein report the case of a 30-year-old Japanese woman with hemophagocytic lymphohistiocytosis (HLH), which is rarely caused by bacteria, secondary to Mycoplasma pneumoniae infection and ensuing hypercytokinemia without pneumonia who was successfully treated with a combination of antibiotics and corticosteroids. Therefore, Mycoplasma pneumoniae infection, which is treatable with antibiotics, should be considered a possible trigger of HLH in patients who present with a viral-like illness without pneumonia.

Secondary Hemophagocytic Syndrome: The Importance of Clinical Suspicion

Hemophagocytic syndrome is a rare and potentially fatal disorder characterized by pathological immune activation associated with a primary familial disorder, genetic mutations, or occurring as a sporadic condition. The latter can be secondary to infections, malignancies, or autoimmune diseases. Clinically, patients present signs of severe inflammation, with unremitting fever, cytopenias, spleen enlargement, phagocytosis of bone marrow elements, hypertriglyceridemia, and hypofibrinogenemia. Increased suspicion is determinant to timely initiate treatment in an attempt to alter the natural history. The authors present three clinical cases of this syndrome, with a brief review of the diagnostic criteria and treatment.

Evaluation of the serum levels of soluble IL-2 receptor and endothelin-1 in children with Crimean-Congo hemorrhagic fever

We aimed to assess the association between serum levels of soluble IL-2 receptor (sIL-2r) and endothelin-1 and severe infection in children with Crimean-Congo hemorrhagic fever (CCHF). Fifty-two patients under 18 years of age with a laboratory- confirmed diagnosis of CCHF and 38 healthy controls were enrolled in the study. Patients were classified into two groups based on disease severity (severe group and non-severe group). The sIL-2r and endothelin-1 levels were observed to be significantly higher in patients with severe CCHF compared with those with non-severe CCHF and the control group (p < 0.05). In addition, those with non-severe CCHF were also found to have a significantly higher sIL-2r level relative to the control group (p < 0.001). Although there was a positive correlation between sIL-2r and endothelin-1 levels, serum levels of both sIL-2r and endothelin-1 were negatively correlated with the platelets count. In children with CCHF, serum levels of sIL-2r and endothelin-1 were increased, and this increase is related to the severity of the disease. In this study, we concluded through prognosis that serum levels of sIL-2r and endothelin-1 might be related, and that hemophagocytic lymphohistiocytosis and endothelial injury might contribute to a pathogenesis of the disease.

Haemophagocytic lymphohistiocytosis presenting as liver failure following Epstein-Barr and prior hepatitis A infections

Haemophagocytic lymphohistiocytosis (HLH) is associated with high mortality even after prompt diagnosis. We present a young man with HLH triggered by two common viral diseases, infectious mononucleosis and hepatitis A. This patient presented with fever, rapidly progressive liver failure, anasarca and cholestasis, followed by anaemia and neutropenia. His carbohydrate antigen 19-9 reached over 9000 U/mL. Initial bone marrow and liver biopsies did not show histological features of malignancy or HLH. The patient was finally diagnosed and treated almost 1 year after the initial symptoms started, and had an excellent response with etoposide and dexamethasone. This case is unusual because it was triggered following mononucleosis in a patient with positive total antibodies against hepatitis A, with rapidly developing liver failure, and also because the patient's response was excellent despite the delay in treatment. It underscores the importance of suspecting HLH when severe systemic illness develops after a viral infection, even in the absence of clear histological features.

Hemophagocytic lymphohistiocytosis--a diagnostic dilemma: two cases and review

Hemophagocytic lymphohistiocytosis (HLH) is a severe inflammatory disorder characterized by activation and proliferation of lymphocytes and histiocytes with cytokine release and uncontrolled hemophagocytosis, especially late in the course of the disease. Clinical features include relapsing fevers, hepatosplenomegaly, cytopenias, lymphadenopathy, and coagulopathy. The diagnosis can be challenging, as the early signs and symptoms are nonspecific and no specific laboratory tests exist. This syndrome is frequently not recognized and has a significant mortality rate. Typical scenarios in which HLH should be considered include mononucleosis (fever, hepatosplenomegaly, and lymphadenopathy) in an infant or young child, aseptic meningitis associated with cytopenias, or a viral syndrome-like illness with cytopenias and lymphadenopathy or splenomegaly, for example. Our approach includes measuring a ferritin level as a screening tool early in the course of such an illness. Two cases of HLH are reviewed, illustrating the frequent complexity of these cases and potential pitfalls to making a prompt diagnosis.

Cytomegalovirus associated haemophagocytic lymphohistiocytosis in the immunocompetent adult managed according to HLH-2004 diagnostic using clinical and serological means only

Haemophagocytic lymphohistiocytosis (HLH) describes a rare, poorly recognised and under-diagnosed immunopathological syndrome whereby there is a highly stimulated yet ineffective multisystem inflammatory response [1]. I present the first case in English literature of Cytomegalovirus (CMV) associated HLH diagnosed by clinical and serological means, and the fourth case of CMV associated haemophagocytic lymphohistiocytosis in an immunocompetent adult, according to HLH-2004 diagnostic guidelines. I include a literature review of CMV associated HLH in adults and raise awareness of checking serum ferritin in patients who present with a sepsis like syndrome. Additionally, this article discusses the merits of HLH-2004 diagnostic work-up without bone marrow biopsy, using clinical and serological means only. I support the reclassification of HLH alongside the other hyperinflammatory syndromes of SIRS, sepsis, septic shock, and MODS to improve understanding and recognition.

A case of hemophagocytic lymphohistiocytosis in a patient with chronic lymphocytic leukemia after treatment with fludarabine, cyclophosphamide, and rituximab chemotherapy, with autopsy findings

Hemophagocytic lymphohistiocytosis (HLH) is rarely described in association with chronic lymphocytic leukemia (CLL), mostly triggered by disease progression or concurrent infection. A 68-year-old male received 4 cycles of fludarabine, cyclophosphamide, and rituximab (FCR) for CLL and achieved a complete response. Twenty-four days after the last chemotherapy, he presented with febrile neutropaenia and was diagnosed with HLH. The diagnosis was based upon persistent fever, pancytopenia, hyperferritinemia, splenomegaly, and hemophagocytosis on bone marrow aspirate. He began treatment with dexamethasone, cyclosporine, and etoposide. Fever resolved and hyperferritinemia improved but pancytopenia persisted. He died 13 days later from septic shock with positive blood cultures. A limited postmortem examination was performed and biopsies were taken from bone marrow, liver, and spleen. Biopsies demonstrated abundant hemophagocytosis by the activated macrophage as stained by CD68. There was no evidence of residual CLL as demonstrated by the lack of lymphocytes which was confirmed by the negative staining of CD79a. Chemotherapy appears to be responsible for the development of HLH in this patient. This is the second reported case of HLH developing after a rituximab-containing chemotherapy.

Clinical analysis and prognostic significance of lymphoma-associated hemophagocytosis in peripheral T cell lymphoma

This study aims to retrospectively analyze the clinical characteristics, treatments, and prognosis of aggressive peripheral T cell lymphoma (PTCL) patients with a lymphoma-associated hemophagocytosis syndrome (LAHS). We compared the clinical features and the overall survival (OS) rates of 159 PTCL patients with and without LAHS as well as the treatment outcomes of these patients with CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) or intensive chemotherapy regimens. We observed that in 23 % (36/159) patients PTCL was associated with LAHS. Different subtypes of PTCL in LAHS patients were diagnosed and peripheral T cell lymphoma, not otherwise specified (PTCL-NOS) was the main subtype (78 %). The median survival rates of the LAHS and non-LAHS groups were 3 and 16 months, respectively. The elevated rates of serum β2-microglobulin, ferritin, fasting triglycerides, and hypofibrinogen levels were higher in the LAHS group, so were bone marrow involvement, liver dysfunction, hepatosplenomegaly, and B symptoms. Three patients who were treated with a plasma exchange had a longer survival time. There was no statistically significant difference in the OS rates between the intensive chemotherapy and CHOP regimen groups (P > 0.05). PTCL patients with LAHS had a poorer prognosis. Awareness of the clinical symptoms and laboratory findings are crucial in order to diagnose LAHS in an early stage and repeated biopsies of multiple bone marrows from different locations in those patients without enlargement of superficial lymph nodes are necessary to improve the diagnosis. Intensive chemotherapy due to its severe toxicity was not obviously advantageous for the OS rate compared to the CHOP regimen.

Macrophage activation syndrome in a patient with pulmonary inflammatory myofibroblastic tumour

We describe for the first time a case of macrophage activation syndrome (MAS) in a patient with a history of inflammatory myofibroblastic tumour (inflammatory pseudotumour, IPT) of the lung and thoracic spine. The patient was admitted to the intensive care unit with a history of prolonged remitting fever, hepatosplenomegaly, bilaterally enlarged thoracic lymph nodes and an acute severe inflammatory response syndrome (SIRS). Up-regulated cytokine production (e.g. IL-1ß and IL-6), increased levels of ferritin and circulating soluble interleukin-2 receptor (sIL-2R, sCD25) led to the differential diagnosis of MAS. Bone marrow aspiration, the main tool for a definite diagnosis, revealed macrophages phagocytosing haematopoietic cells. Immunosuppressive therapy with corticosteroids and cyclosporine was an effective treatment in this patient.