Reduced Tyk2/SHP-1 interaction and lack of SHP-1 mutation in a kindred of familial hemophagocytic lymphohistiocytosis.

Familial hemophagocytic lymphohistiocytosis (FHLH) is an autosomal recessive disease with features similar to those of the murine motheaten phenotype resulting from mutations of protein tyrosine phosphatase SHP-1. This has raised the possibility that defects in SHP-1 or SHP-1-regulated signaling molecules may be present in FHLH. In this study, we examined SHP-1 protein and transcript in the peripheral blood mononuclear cells (PBMC) of an FHLH family. Our results show that the FHLH patient and the parents express comparable levels of a single SHP-1 protein and that the SHP-1 cDNA clone from the patient contains no mutation in the coding region. Interestingly, a reduced association of SHP-1 with the Jak family kinase Tyk2 was detected in the patient and the defect appears to have been inherited from one of the parents. This reduced SHP-1/Tyk2 association is likely due to a defect in Tyk2 or in cellular factors regulating Tyk2, because we found no abnormalities in SHP-1 or in SHP-1 association with the other Jak kinases. These data demonstrate that the SHP-1 gene is intact in FHLH and that the defect in some cases with this disease may involve signaling molecules regulated by SHP-1.

Haemophagocytic syndromes in adults: current concepts and challenges ahead.

Haemophagocytic syndrome (HS), also referred to as haemophagocytic lymphohistiocytosis or macrophage activation syndrome, comprises a heterogeneous group of disorders featuring sepsislike characteristics typically combined with haemophagocytosis, hyperferritinemia, hypercytokinemia and variable cytopenias, often resulting in fatal multiple organ failure. The availability of widely accepted diagnostic and therapeutic guidelines for the hereditary, paediatric forms of HS has improved outcome and lead to a better pathophysiological understanding. Although similar, reactive (secondary) HS in adults are distinct from childhood forms. Limited awareness of this type of disorder and the absence of clinical guidelines are to blame for delayed diagnosis and dire prognosis in many cases of HS in adults. Moreover, the underlying mechanisms of adult HS remain to be unravelled yet. We summarise general features of HS and discuss particular characteristics of this disorder inadults. Furthermore, we describe a simple screening and diagnostic algorithm based on serum markers of macrophage activation (ferritin, soluble CD163 and soluble CD25) and morphological evidence of haemophagocytosis. Application of this strategy might be instrumental for recruiting patients for clinical studies, early diagnosis and hence improved prognosis. Indeed, there is evidence that a subgroup of patients with systemic inflammatory response syndrome presenting with signs of macrophage activation benefit from early administration of intravenous immunoglobulins. Clinical studies are needed to validate our diagnostic approach and to establish well defined prognostic and therapeutic algorithms. Finally, we will discuss whether similar processes contribute to HS in adults compared to childhood forms.

Possible role of short-term parenteral nutrition with fat emulsions for development of haemophagocytosis with multiple organ failure in a patient with traumatic brain injury.

We describe a case of life-threatening haemophagocytosis after a short term nutrition with fat emulsion in a 21-year-old woman who sustained an isolated traumatic brain injury. Hypertriglyceridemia and "creaming plasma" were observed after a three-day period of parenteral fat nutrition (Intralipid 20%). She also developed rash, high fever (40-41 degrees C), hypertension, raised intracranial pressure, hepatic and renal failure, haemolysis, marked thrombocyto- and leucopenia, coagulation disorder and pulmonary failure. These symptoms, together with a typical bone marrow smear, indicated haemophagocytosis with hyperactivation of the monocyte-macrophage system. We suggest that the hyperactivation was an effect of fat retention or agglutination of the fat particles; the initial triggering mechanism may emanate from the brain damage by hypercytokinaemia. The steroid treatment given most likely contributed to the successful outcome, as indicated by the stepwise improvement related in time to the steroid infusions.

Neuron-specific enolase in hemophagocytic lymphohistiocytosis: a potential indicator for macrophage activation?

To determine the pathogenesis of hemophagocytic lymphohistiocytosis (HLH), serum levels of neuron-specific enolase (NSE) and cytokine profiles were investigated. Serum concentrations of NSE and several cytokines were measured by immunoassays, and the association was evaluated in 18 HLH patients. Serum NSE levels increased (> 10 ng/mL) in 27/29 samples (93%) during the active febrile phase, the mean level of which (35.9 ng/mL) was much higher than that during the remission phase (11.2 ng/mL) (P = .001). The peak levels of NSE in 11 patients who required cytotoxic agents were higher than those in 7 patients without chemotherapy, 64.6 +/- 49.4 and 17.9 +/- 12.9, respectively (P = .265). The NSE levels correlated positively with the levels of interferon (IFN)-gamma (Pearson's correlation coefficient [r] = 0.408, P = .044), soluble interleukin-2 receptor (sIL-2R) (r = 0.464, P = .048), lactate dehydrogenase (r = 0.830, P < .00001), aspartate aminotransferase (r = 0.531, P = .003), and ferritin (r = 0.715, P < .00001), and correlated negatively with platelet count (r = -0.422, P = .021), but not with other parameters, including tumor necrosis factor-alpha, IL-1 beta, IL-18, soluble Fas ligand and C-reactive protein. Multiple regression analysis indicated that the correlation of NSE with platelet count was independent of other correlations. Sequential NSE changes well reflected the clinical course of patients. Immunohistochemical staining revealed an appreciable number of NSE-positive histiocytes in bone marrow specimens with florid hemophagocytosis. These results suggest that the circulating NSE originated from macrophages stimulated with IFN-gamma/sIL-2R, and partly from the destruction of platelets. Serum NSE level may be a useful marker for predicting the disease progression of HLH.

The serum cytokine profiles of lymphoma-associated hemophagocytic syndrome: a comparative analysis of B-cell and T-cell/natural killer cell lymphomas.

To elucidate the differences in pathogenesis between lymphoma-associated hemophagocytic syndromes (LAHS) of the T-cell/ natural killer cell (T/NK) and B-cell (B) types, we comparatively analyzed the clinical features and serum cytokine profiles of 33 patients with LAHS registered in the Kyoto University Hematology/Oncology Study Group. The serum cytokine levels of each patient group (B-LAHS versus T/NK-LAHS) were expressed as the ratio of the median to the upper normal values of the respective cytokines and were as follows: 19.05 versus 13.99 for soluble interleukin 2 (IL-2) receptor, 0.67 versus 0.67 for granulocyte-macrophage colony-stimulating factor (GM-CSF), 0.64 versus 1.26 for G-CSF, 5.70 versus 3.61 for M-CSF, 1.54 versus 3.39 for interferon gamma (IFN-gamma), 13.17 versus 1.17 for IL-6, 6.88 versus 1.58 for tumor necrosis factor alpha (TNF-alpha), 0.71 versus 0.41 for IL-1beta, 1.99 versus 0.21 for IL-12, and 105.32 versus 29.65 for IL-10. The serum levels of IL-6, TNF-alpha, and IL-10 were significantly higher in the B-LAHS group, whereas those of IFN-y were significantly lower. These differences between the 2 groups may reflect a difference in the pathogenesis Higher serum levels of IL-6, TNF-alpha, and IL-10 may be derived at least partly from neoplastic B-cells themselves In addition, the extremely high serum levels of IL-10 suggest that a compensatory anti-inflammatory process may operate in both groups and give rise to a profound immunosuppressive state and a poor outcome.

Interleukin-18 in hemophagocytic lymphohistiocytosis.

Hemophagocytic lymphohistiocytosis (HLH) is characterized by dysregulated hyperactivation of macrophages and T helper 1 (Th1) cells accompanied by excessive secretion of inflammatory cytokines. Although TNF-alpha and IFN-gamma are known to be important factors for the development of the disease, the mechanism of their overproduction has not been clarified, yet. We measured serum IL-18 levels of patients with HLH to investigate the possible significance of IL-18 in its pathophysiology, especially in IFN-gamma production. IL-18 levels were significantly increased in all patients with HLH compared with healthy controls. A significant correlation was observed between IL-18 and IFN-gamma levels. In addition to IFN-gamma and soluble Fas ligand (sFasL), IL-18 levels significantly correlated with disease activity. IL-18 may play important roles in the pathogenesis of HLH, particularly through induction of Th1 cells. In addition, IL-18 measurement may not only be useful for the diagnosis, but also for the evaluation of disease activity.

Familial hemophagocytic lymphohistiocytosis: too little cell death can seriously damage your health.

Familial hemophagocytic lymphohistiocytosis (FHL) is a rare and fatal disease of early childhood characterized by a non-malignant accumulation of activated T lymphocytes and histiocytes in the reticuloendothelial system. Moreover, immune system derangement, with prominent hypercytokinemia and low or absent cytotoxic T and natural killer (NK) cell activity, is a consistent feature of this autosomal recessive disorder. Recent work has demonstrated that the degree of spontaneous caspase activation in FHL lymphocytes is attenuated in vitro whereas Fas-mediated caspase activation and apoptosis induction remains unmitigated, and FHL can thus be distinguished from the related chronic disorder of immune regulation termed autoimmune lymphoproliferative syndrome or ALPS. However, subsequent studies have identified mutations in the gene encoding perforin, a cytotoxic granule constituent required for apoptotic killing of target cells, in a number of FHL patients. Hence, the underlying defect in FHL may be conceived of as a lack of apoptosis triggering within the immune system, rather than apoptosis resistance per se. These observations represent an important step in our understanding of the pathogenesis of FHL and also serve to emphasize the pivotal role of cellular (perforin-based) cytotoxicity in the regulation of immune homeostasis.

Epstein-Barr virus-associated hemophagocytic syndrome.

A virus-associated hemophagocytic syndrome (VAHS) is a non-neoplastic, generalized histiocytic proliferation with prominent hemophagocytosis associated with a systemic viral infection. Epstein-Barr virus (EBV) is one candidate for this association but serologic and molecular biologic studies have been lacking in many cases. Although VAHS is generally a benign process, EBV-associated hemophagocytic syndrome (EBV-AHS) is often fatal and has a relatively high mortality rate. Therefore, EBV-AHS must be distinguished from VAHS caused by other viruses. Recent evidence indicates that the pathophysiology in EBV-AHS appears to be mediated by the unrestricted release of cytokines produced by the EBV-infected T cells. Clinical and laboratory findings, the differential diagnosis, virology studies, pathophysiology, and treatment in EBV-AHS are reviewed.

Reactive haemophagocytic syndrome in human immunodeficiency virus infection.

The reactive or virus-associated haemophagocytic syndrome (RHS) has been described in association with several different infections and is regarded as clinically and pathologically distinct from malignant histiocytosis. A case is described of this syndrome in a 30-year-old HIV-antibody positive homosexual male who presented with fever, pancytopenia, lymphadenopathy, and massive splenomegaly. The fever and haematological abnormalities resolved following splenectomy, and the patient remains well after 12 months. Prominent histiocytic haemophagocytosis was seen in both the spleen and an abdominal lymph node. Exhaustive tests failed to demonstrate any infectious agent other than human immunodeficiency virus, indicating this to be a case of this syndrome occurring in association with HIV infection.

Hemophagocytic syndrome associated with antiepileptic drug.

An 8-year-3-month-old male with right porencephaly and epilepsy was found to have skin rash 2 weeks after the beginning of treatment with lamotrigine. One month later he suffered from impaired liver function and pancytopenia in the presence of hypocellular bone marrow with hemophagocytosis. No evidence of infection was evident. Intravenous immunoglobulin and steroid were administered with discontinuation of lamotrigine; the hemogram and liver function profile improved dramatically. Hemophagocytic syndrome should be considered a possible cause of pancytopenia in patients taking new antiepileptic drugs such as lamotrigine.

Reactive macrophage activation syndrome: a simple screening strategy and its potential in early treatment initiation.

QUESTIONS UNDER STUDY: starting treatment of reactive macrophage activation syndromes as early as possible (rMAS, haemophagocytic lymphohistiocytosis), e.g., with intravenous immunoglobulins (IVIG), seems to be essential for optimal outcome. However, there is no diagnostic gold standard which reliably indicates need for early treatment. We used a simple screening strategy consisting of serum ferritin measurements and/or morphological assessment of haemophagocytosis and compared the studied patient population with published series. METHODS: Retrospective analysis of clinical and laboratory data of 57 patients experiencing 60 episodes of rMAS. RESULTS: Screening by serum ferritin measurements and/or morphological assessment of haemophagocytosis of patients presenting with a systemic inflammatory response syndrome (SIRS) indicates that rMAS might be considerably more frequent than stated in the literature. Serum ferritin exceeded >10,000 microg/L in 91% rMAS episodes. Although the patient population studied was otherwise similar in most aspects to the published rMAS series, the fact that 40% of patients fulfilled the criteria for Still's disease (SD) as the disorder underlying rMAS is remarkable and questions the distinct nature of the two diseases. IVIG responders and non-responders did not differ regarding their initial characteristics with exception to the timepoint of IVIG administration, confirming the importance of early treatment initiation. Malignancy-associated rMAS however, has a poor prognosis and seems to be refractory to manipulation with IVIG in most instances, even when responding initially. CONCLUSIONS: rMAS has to be considered in patients with a SIRS- or SD-like clinical presentation. Hyperferritinaemia >or=10,000 microg/l seems to be a good marker for defining patients with or at risk for developing rMAS and should be completed with a morphological assessment of haemophagocytosis. The perception of acute SD and rMAS as two distinct entities has to be questioned at least in a subgroup of patients.

A case report of the effect of plasma exchange on reactive hemophagocytic syndrome associated with toxic shock syndrome.

We report here the case of a patient suffering from hemophagocytic syndrome (HPS) associated with toxic shock syndrome (TSS). A 50-year-old man was admitted because of fever, watery diarrhea and shortness of breath. Clinical analysis revealed systemic cyanosis, sunburn-like erythema and septic shock. Staphylococcus aureus was identified from both blood and sputum culture and the serum enterotoxin A antibody test was positive, suggesting that this was a case of TSS. Though the respiratory and hemodynamic status improved by the mechanical ventilation, fluid resuscitation with catecholamine and antibiotic therapy, the platelet count decreased rapidly. Bone marrow aspiration revealed a large quantity of hemophagocytosis by macrophages. This reactive HPS was treated not with immunosuppressive drugs but with therapeutic plasma exchange in order to prevent worsening of S. aureus infection. After plasma exchange, the circulating macrophage colony-stimulating factor (M-CSF) level was reduced and the platelet count increased rapidly. Bacteria associated HPS remains a difficult diagnosis with high mortality and there is a crucial question of whether this should be treated with immunosuppressive drugs. The patient's clinical course would suggest that the therapeutic plasma exchange should be considered as a therapeutic tool for the bacteria associated HPS instead of immunosuppressive drugs.

Chronic active Epstein-Barr virus infection and virus-associated hemophagocytic syndrome.

We describe two unusual cases of Epstein-Barr virus infection that were complicated by the virus-associated hemophagocytic syndrome, predominantly involving the spleen. Both patients were young adult men who presented with fever, pancytopenia, and hepatosplenomegaly. Both had prompt symptomatic and hematologic improvement following splenectomy. Severe constitutional symptoms recurred in one patient 1 month after splenectomy, and he died of septicemia 2 months later. In both cases, there was prominent hemophagocytosis in the splenic red pulp. Some hemophagocytosis was also noted in the liver from the fatal case. Unexpectedly, no hemophagocytosis was detected in the bone marrow biopsy specimens or marrow aspirates obtained from these patients. The DNA hybridization studies detected Epstein-Barr virus genomes in spleen samples from both patients, and both patients had atypical patterns of serologic response to the virus, suggesting that a defective immune response may lead to an unrestrained viral proliferation. We conclude that there is an association between chronic active Epstein-Barr virus infection and the hemophagocytic syndrome, but that the tissue distribution of the hemophagocytosis may be variable.

Serous fluid cytology as a means of detecting hemophagocytosis in Epstein-Barr virus-induced autoimmune hemolytic anemia.

The case of a 22-yr-old male who after a brief febrile episode developed autoimmune hemolytic anemia and right pulmonary infiltrate with pleural effusion is presented. Cytologic examination of the pleural fluid revealed lymphocytosis and hemophagocytosis, primarily of red blood cells (RBCs) by mature histiocytes. There was accompanying splenomegaly, laboratory evidence of hepatic dysfunction, and retroperitoneal lymphadenopathy. Besides profound reduction of red blood cells in the peripheral blood, there was reduction of lymphocytes and platelets. As a neoplastic process was ruled out by bone marrow and pleural biopsies, the disease was considered to be virus-induced and was halted and progressively regressed with early institution of vigorous antiinflammatory therapy with adrenocortical steroids. Upon reviewing the case, examination of the bone marrow biopsy disclosed limited hemophagocytosis of RBCs and lymphocytes by histiocytes and considerable viral cytopathic effect on hematopoietic cells (red and white cell precursors and megakaryocytes), which by appropriate immunolabelling was identified as induced by Epstein-Barr virus. A virus-related acquired hemophagocytic syndrome in its early stages was probably present, yet an undesirable clinical outcome was averted by early institution of vigorous steroid therapy. The need to recognize early hemophagocytic changes in cytologic specimens for early institution of appropriate therapy is emphasized. The possibility of erythrophagocytosis, also manifested during the course of an autoimmune hemolytic process and unrelated to hemophagocytic syndrome, is discussed.

Two cases of malignant lymphoma complicated by hemophagocytosis resembling orbital cellulitis.

Two patients with malignant lymphoma complicated by hemophagocytic syndrome (HPS) are reported. Their clinical signs at onset were similar to those of orbital cellulitis. Lymphoma complicated by hemophagocytosis is called lymphoma-associated hemophagocytic syndrome (LAHS) and its prognosis is reported to be very poor. As far as we know, this is the first report in the ophthalmological field. In our patients, we suspected that the lesions occurred from the orbit or skin of this area. The first patient was a 22-year-old man and the second patient a 16-year-old girl. The diagnosis was very difficult at the onset of disease. They died within 6 months after the first ophthalmological examination. When orbital cellulitis is suspected and antibiotic therapy is ineffective, we should suspect HPS and should examine serum ferritin, which is a good marker of HPS. Early biopsy and consultation with a hematologist are very important.

Hematophagic histiocytosis: a clinicopathologic analysis of 23 cases with special reference to the association with peripheral T-cell lymphoma.

The clinicopathologic features of 23 patients with hematophagic histiocytosis (HH) are described. All of them exhibited increased histiocytes associated with hemophagocytosis in the marrow. The patients usually presented with fever, hepatosplenomegaly, lymphadenopathy, and cytopenia. The underlying illnesses were heterogeneous, including non-Hodgkin's lymphoma in 17, systemic lupus erythematosus in one, diabetes mellitus in one, acute myelomonocytic leukemia in one, myelodysplastic syndrome in one, and unknown cause in two. Among 17 non-Hodgkin's lymphoma, 14 were peripheral T-cell lymphoma, two were B-cell lymphoma, and one was an undefined phenotype. Among 14 patients with peripheral T-cell lymphoma, six of the patients had nasal T-cell lymphoma. Five of these 14 patients initially diagnosed as malignant histiocytosis turned out to be T-lineage lymphoma after immunophenotypic studies. Active infections, most of viral origin, were documented in eight patients, including Epstein-Barr virus in three, cytomegalovirus in three, herpes simplex virus in three, Pseudomonas aeruginosa in one, Bacteroides vulgatus in one, and mycoplasma in one. Some of them had mixed virus and bacteria infection. Sixteen (70%) of our patients died of their acute illness within 10 weeks of the diagnosis of HH. In the past, the clinical and histologic differentiation between hematophagic histiocytosis and true histiocytic neoplasm (histiocytic medullary reticulosis/malignant histiocytosis) has proved difficult, but now these can be distinguished with immunohistologic, immunogenetic, and cytogenetic studies, especially in the cases of peripheral T-cell lymphoma with hemophagocytic syndrome.

[Reactive hemophagocytic syndrome: analysis of a series of 7 cases]. / Síndrome hemofagocítico reactivo: análisis de una serie de siete casos.

We report a series of seven patients with reactive hemophagocytic syndrome, which was quite characteristic of its etiological spectrum. Infections were the leading cause, among them a case associated with HIV and another one with Salmonella enteritidis (a hitherto unreported association). The clinical findings consisted of fever, hepatomegaly, splenomegaly, lymphadenopathy, rash and pancytopenia. The diagnosis was carried out by bone marrow aspiration-biopsy except in two patients who were diagnosed at autopsy. The difficulty of the differentiation from malignant histiocytosis is discussed: one case of hemophagocytic syndrome due to diphenylhydantoin toxicity (the second reported one in the literature) was histologically undistinguishable from it. We think that, in any etiology, hemophagocytic syndrome is a reactive syndrome with variable intensity. The need for extensive microbiological investigation even in cases of histiocytosis of neoplastic appearance is emphasized.

Clinical and biological significance of clonal macrophage detection in hemophagocytic syndrome.

By using the method of clonal analysis the evidence to prove that Hemophagocytic syndrome (HPS) is reactive or malignant was investigated to probe into the pathogenesis of HPS and its relations with clinical prognosis. The macrophages abnormally proliferated in bone marrow were isolated. Electrophoresis analysis was made after DNA extraction, enzyme restriction of human ardrogen receptor (HUMARA) genetic locus, and PCR amplification. In the 9 specimens, clonal proliferation was found in 2 cases and nonclonal proliferation in 7. Among the 7 cases of nonclonal proliferation, 3 were voluntarily discharged without clinical outcome, 2 cases fully recovered after 2-3 week treatment of large dose gamma globulin intravenous drip and hormone therapy, 1 case died at the 43th day after the hormone and anti-infection therapy, and one case was found to have granular leukoblast in peripheral blood after 3 weeks and diagnosed as having M2a after bone puncture. For the two patients with clonal proliferation, one obtained remission after chemotherapy and the other was died after 32 days without chemotherapy. It was concluded that there do exist clonal or malignant proliferation in HPS, so not every case is reactive.

[Syndrome of macrophagic activation with hemophagocytosis in human immunodeficiency virus infection]. / Syndrome d'activation macrophagique avec hémophagocytose au cours de l'infection par le virus de l'immunodéficience humaine.

The authors report two cases of hematophagic histiocytosis in HIV positive patients. In the first case, a patient with Kaposi sarcoma and Mycobacterium avium infection had a rapidly deteriorating course with progressive pancytopenia and death, as generally described in the literature. In the second case, hematophagic histiocytosis appeared during HIV primo infection and reversed spontaneously. Although few cases of hemophagocytic syndrome have been reported in HIV positive patient, it could represent an underestimated cause of pancytopenia. Both opportunistic microorganisms and HIV are able to cause hematophagic histiocytosis.

[Hyperferritinemia in Still syndrome in the adult and reactive hemophagocytic syndrome]. / Hyperferritinämie beim Still-syndrom des Erwachsenen und reaktives hämophagozytisches syndrom.

This report describes the fatal outcome of a case of adult onset Still's disease in a 46-year old man. The diagnosis was made according to the 1992 criteria, proposed by Yamaguchi. Nine months after the initial disease manifestations a rapid deterioration with progressive hepatosplenomegaly developed. In parallel, pancytopenia and marked hyperferritinemia could be detected. Transjugular liver biopsy revealed the presence of a hemophagocytic syndrome. The course of the disease was refractory to any form of treatment and the patient died from disseminated intravascular coagulation, hepatic and pulmonary failure. Pathogenetic mechanisms and possible associations between Still's disease and reactive hemophagocytic syndrome are discussed.