Two siblings with PRKDC defect who presented with cutaneous granulomas and review of the literature.

V(D)J recombination, during which recognition and repair of broken DNA chains are accomplished by non-homologous end joining pathway, is a critical process in B and T cell development.Null mutations of each enzyme or protein of this pathway result in T- B- NK+ severe combined immunodeficiency whereas hypomorphic mutations result in atypical(leaky)severe combined immunodeficiency forms. We present two siblings with PRKDC (Protein Kinase, DNA-Activated, Catalytic Polypeptide) mutation who presented with granulomatous skin lesions and recurrent lung infections. Primary immune deficiencies may initially present with skin findings. Disruption in central and peripheral B-cell tolerance and impaired intrathymic T-cell maturation,a central player in T-cell tolerance, have been identified as the mechanism of autoimmunity and granuloma seen in patients. The variation in clinical phenotypes of patients with PRKDC mutation suggests that additional factors such as modifying genes, epigenetic and environmental factors may affect the severity and clinical phenotype of the disease. Functional studies during the follow-up and evaluation before and after hematopoeitic stem cell transplantation will hopefully increase our knowledge about the autoimmune and inflammatory process of the disease spectrum.

Case Report: Multicentric Reticulohistiocytosis Associated With Posterior Mediastinal Adenosquamous Carcinoma, Antinuclear Antibody Positivity and Lupus Anticoagulant Positivity.

Multicentric reticulohistiocytosis (MRH) is a rare systemic disease of non-Langerhans cell histiocytosis. A number of studies in the literature have documented that it can coexist with malignancy or autoimmune disease, making it difficult to determine the most appropriate therapy. Here, we present a case study of MRH associated with posterior mediastinal adenosquamous carcinoma along with antinuclear antibody positivity and lupus anticoagulant positivity. The patient experienced 6 months of clinical benefit after surgical resection and chemoradiotherapy of the mediastinal malignancy. This case adds to the available literature on multicentric reticulohistiocytosis associated with different types of malignancy and provides supplementary clinical data on the coexistence of this syndrome with malignancy and immune system abnormalities. To the best of our knowledge, this is the first case study describing MRH accompanied by posterior mediastinal adenosquamous carcinoma and lupus anticoagulant positivity. The unknown aetiology and polymorphic clinical presentation of MRH warrants further investigation.

The functional basis for hemophagocytic lymphohistiocytosis in a patient with co-inherited missense mutations in the perforin (PFN1) gene.

About 30% of cases of the autosomal recessive immunodeficiency disorder hemophagocytic lymphohistiocytosis are believed to be caused by inactivating mutations of the perforin gene. We expressed perforin in rat basophil leukemia cells to define the basis of perforin dysfunction associated with two mutations, R225W and G429E, inherited by a compound heterozygote patient. Whereas RBL cells expressing wild-type perforin (67 kD) efficiently killed Jurkat target cells to which they were conjugated, the substitution to tryptophan at position 225 resulted in expression of a truncated ( approximately 45 kD) form of the protein, complete loss of cytotoxicity, and failure to traffic to rat basophil leukemia secretory granules. By contrast, G429E perforin was correctly processed, stored, and released, but the rat basophil leukemia cells possessed reduced cytotoxicity. The defective function of G429E perforin mapped downstream of exocytosis and was due to its reduced ability to bind lipid membranes in a calcium-dependent manner. This study elucidates the cellular basis for perforin dysfunctions in hemophagocytic lymphohistiocytosis and provides the means for studying structure-function relationships for lymphocyte perforin.

Perforin gene defects in familial hemophagocytic lymphohistiocytosis.

Familial hemophagocytic lymphohistiocytosis (FHL) is a rare, rapidly fatal, autosomal recessive immune disorder characterized by uncontrolled activation of T cells and macrophages and overproduction of inflammatory cytokines. Linkage analyses indicate that FHL is genetically heterogeneous and linked to 9q21.3-22, 10q21-22, or another as yet undefined locus. Sequencing of the coding regions of the perforin gene of eight unrelated 10q21-22-linked FHL patients revealed homozygous nonsense mutations in four patients and missense mutations in the other four patients. Cultured lymphocytes from patients had defective cytotoxic activity, and immunostaining revealed little or no perforin in the granules. Thus, defects in perforin are responsible for 10q21-22-linked FHL. Perforin-based effector systems are, therefore, involved not only in the lysis of abnormal cells but also in the down-regulation of cellular immune activation.

Upregulation of tumor necrosis factor-alpha gene by Epstein-Barr virus and activation of macrophages in Epstein-Barr virus-infected T cells in the pathogenesis of hemophagocytic syndrome.

A potentially fatal hemophagocytic syndrome has been noted in patients with malignant lymphomas, particularly in EBV-infected T cell lymphoma. Cytokines, such as interferon-gamma (IFN-gamma), TNF-alpha, and IL-1alpha, are elevated in patients' sera. To verify whether infection of T cells by EBV will upregulate specific cytokine genes and subsequently activate macrophages leading to hemophagocytic syndrome, we studied the transcripts of TNF-alpha, IFN-gamma, and IL-1alpha in EBV-infected and EBV-negative lymphoma tissues. By reverse transcription PCR analysis, transcripts of TNF-alpha were detected in 8 (57%) of 14 EBV-infected T cell lymphomas, higher than that detected in EBV-negative T cell lymphoma (one of six, 17%), EBV-positive B cell lymphoma (two of five, 40%) and EBV-negative B cell lymphomas (one of seven, 14%). Transcripts of IFN-gamma were consistently detected in T cell lymphoma and occasionally in B cell lymphoma, but were independent of EBV status. IL-1alpha expression was not detectable in any category. Consistent with these in vivo observations, in vitro EBV infection of T cell lymphoma lines caused upregulation of TNF-alpha gene, and increased secretion of TNF-alpha, but not IFN-gamma or IL-1alpha. Expression of TNF-alpha, IFN-gamma, and IL-1alpha was not changed by EBV infection of B cell lymphoma lines. To identify the specific cytokine(s) responsible for macrophage activation, culture supernatants from EBV-infected T cells were cocultured with a monocytic cell line U937 for 24 h. Enhanced phagocytosis and secretion of TNF-alpha, IFN-gamma, and IL-1alpha by U937 cells were observed, and could be inhibited to a large extent by anti-TNF-alpha (70%), less effectively by anti-IFN-gamma (31%), but almost completely by the combination of anti-TNF-alpha and anti-IFN-gamma (85%). Taken together, the in vivo and in vitro observations suggest that infection of T cells by EBV selectively upregulates the TNF-alpha expression which, in combination with IFN-gamma and probably other cytokines, can activate macrophages. This study not only highlights a probable pathogenesis for virus-associated hemophagocytic syndrome, but also suggests that anti-TNF-alpha will have therapeutic potential in the context of their fatal syndrome.

Multicentric reticulohistiocytosis with positive anticyclic citrullinated antibodies.

This is a case report of a woman with multicentric reticulohistiocytosis with positive anticyclic citrullinated antibodies. This patient had been misdiagnosed with rheumatoid arthritis for many years. Recently, she presented with symmetric distal interphalangeal joint destruction and papules along her nail beds. Her clinical presentation, laboratory data, radiographic and histologic findings were all consistent with multicentric reticulohistiocytosis, not rheumatoid arthritis. This is the first case report of a patient with multicentric reticulohistiocytosis that tested positive for anticyclic citrullinated antibodies.

AM-3K, an anti-macrophage antibody, recognizes CD163, a molecule associated with an anti-inflammatory macrophage phenotype.

CD163 is a member of the scavenger receptor cysteine-rich superfamily restricted to the monocyte/macrophage lineage and is thought to be a useful marker for anti-inflammatory or alternatively activated macrophages. In this study we used mass spectrometric analysis to determine that the antigen recognized by the antibody AM-3K, which we previously generated as a tissue macrophage-specific monoclonal antibody, was CD163. An anti-inflammatory subtype of macrophages stimulated by dexamethasone or interleukin-10 showed strong reactivity for AM-3K and increased expression of CD163 mRNA. Immunohistochemical staining of routinely processed pathological specimens revealed that AM-3K recognized a specialized subpopulation of macrophages. In granulomatous diseases such as tuberculosis, sarcoidosis, or foreign body reactions, tissue macrophages around granulomas, but not component cells of the granulomas such as epithelioid cells and multinucleated giant cells, showed positive staining for AM-3K. In atherosclerotic lesions, scattered macrophages in diffuse intimal lesions were strongly positive for AM-3K, whereas foamy macrophages in atheromatous plaques demonstrated only weak staining. We therefore suggest that, in routine pathological specimens, AM-3K is a useful marker for anti-inflammatory macrophages because these cells can be distinguished from inflammatory or classically activated macrophages. Because AM-3K cross-reacts with macrophage subpopulations in different animal species including rats, guinea pigs, rabbits, cats, dogs, goats, pigs, bovine species, horses, monkeys, and cetaceans, it will have wide application for detection of CD163 in various animals.

Multicentric reticulohistiocytosis.

Multicentric reticulohistiocytosis is a rare granulomatous disease of unknown etiology, characterized by cutaneous nodules and destructive arthritis. Skin lesions can cause significant deformity, and approximately half of affected patients develop a severe disabling arthritis. The disease is often associated with malignancy; however, the paraneoplastic nature of multicentric reticulohistiocytosis is not established. The diagnosis is confirmed by the presence of oncocytic ("ground-glass") histiocytes and multinucleated giant cells on histopathology of the cutaneous nodules and the synovial membrane.

[Hemophagocytic syndrome: diagnostic problems]. / Zespól hemofagocytarny: trudnosci diagnostyczne.

Hemophagocytic syndrome (HS) is a rare but life-threatening disease caused by inappropriate activation of T-lymphocytes and histiocytes, hipercytokinemia and hemophagocytosis. The most common symptoms are fever, hepatosplenomegaly, unspecific neurological abnormalities, pancytopenia, coagulopathy, hiperferritinemia and lipid abnormalities. HS is classified into two forms: primary, inherited (Familial Hamophagocytic Lymphohistiocytosis--FHL) and secondary (associated with infection, malignancy, autoimmune disease). In spite of the fact that diagnostic guidelines are available it often remains unrecognised. Prognosis of HS depends on the form of disease and in case of secondary HS on the underlying disease. Development of the treatment protocols (HLH-94, HLH-2004) which combine immunochemiotherapy with hematopoietic stem cell transplantation has strongly improved prognosis in HS especially in the primary form. Three-year overall survival for children with HS is now over 50%. Early diagnosis and appropriate therapy is crucial for effectiveness of the treatment. Popularisation of the knowledge about the syndrome, diagnostic guidelines and treatment protocols can contribute to more frequent appropriate recognition of HS and to improvement of the treatment results.

Review of hemophagocytic lymphohistiocytosis (HLH) in children with focus on Japanese experiences.

Hemophagocytic lymphohistiocytosis (HLH) is characterized by fever and hepatosplenomegaly associated with pancytopenia, hypertriglyceridemia and hypofibrinogenemia. Increased levels of cytokines and impaired natural killer activity are biological markers of HLH. HLH can be classified into two distinct forms, including primary HLH, also referred to as familial hemophagocytic lymphohistiocytosis (FHL), and secondary HLH. Although FHL is an autosomal recessive disorder typically occurring in infancy, it is important to clarify that the disease may also occur in older patients. It is now considered that FHL is a disorder of T-cell function; moreover, clonal proliferation of T lymphocytes is observed in a few FHL patients, and cytotoxicity of these T lymphocytes for target cells is usually impaired. In 1999, perforin gene (PRF1) mutation was identified as a cause of 20-30% of FHL (FHL2) cases. In Japan, two specific mutations of PRF1 were also detected. Furthermore, in 2003, MUNC13-4 mutations were identified in some non-FHL2 patients (FHL3). Identification of other genes responsible for remaining cases is a major concern. Hematopoietic stem cell transplantation (HSCT) has been established as the only accepted curative therapy for FHL. Thus, appropriate diagnosis and prompt treatment with HSCT are necessary for FHL patients. Genetic analysis for PRF1 and MUNC13-4 and functional assay of cytotoxic T lymphocytes are recommended to be performed in each patient. In those patients displaying impaired cytotoxic function but lacking genetic defects, samples should be employed for identification of unknown genes. In the near future, an entire pathogenesis should be clarified in order to establish appropriate therapies including immunotherapy, HSCT and gene therapy.

Hemophagocytic lymphohistiocytosis. Report of 122 children from the International Registry. FHL Study Group of the Histiocyte Society.

Hemophagocytic lymphohistiocytosis (HLH) is a rare, often fatal, disease of early infancy. The diagnosis of HLH is frequently delayed or made at autopsy because no genetic or biologic marker has been identified. To improve the classification and treatment of HLH, the Histiocyte Society has established an 'International Registry for HLH'. Data collected included family history, clinical and laboratory features at the onset of illness, and treatment outcome. Stringent diagnostic criteria (ie fever, splenomegaly, cytopenia, hypertriglyceridemia, and/or hypofibrinogenemia, and hemophagocytosis without evidence of malignancy) were used for patient selection. One hundred and twenty-two patients (61 males, 61 females) were enrolled from 17 centers in 11 countries. The rate of parental consanguinity was 24%. A positive family history was reported in 49% of cases including two pairs of affected male twins. The median age at disease onset was 2.9 months, with no difference between familial and sporadic cases. Age at onset was similar in affected sibs from 10 of 14 families, but in four up to 3-year differences were observed. Hemophagocytosis was present at diagnosis in 75%. An associated infection (usually by common viral pathogens) was reported in 50 of the 122 (41%) cases, of which 25 had familial disease. Natural killer activity was impaired in 36 of 37 patients studied. Chromosome analysis was normal in all tested patients. A decreased frequency of HLA-B7 and B8 alleles and increased frequency of HLA-B21 and DQ3 were observed. The estimated 5-year survival (SE) was 21% (18.7) for all patients. It was 66% (37.8) for patients who received allogeneic bone marrow transplant and 10.1% (9.6) for patients treated with chemotherapy alone (P=0.0001). None of the previously proposed prognostic indicators (age, associated infection, cerebrospinal fluid pleocytosis, family history) correlated with treatment outcome.

Identification of novel MUNC13-4 mutations in familial haemophagocytic lymphohistiocytosis and functional analysis of MUNC13-4-deficient cytotoxic T lymphocytes.

BACKGROUND: Familial haemophagocytic lymphohistiocytosis (FHL) has an autosomal recessive mode of inheritance and consists of at least three subtypes. FHL2 subtype with perforin (PRF1) mutation accounts for 30% of all FHL cases, while FHL with MUNC13-4 mutation was recently identified and designated as FHL3 subtype. OBJECTIVE: To examine MUNC13-4 mutations and the cytotoxic function of MUNC13-4 deficient T lymphocytes in Japanese FHL patients METHODS: Mutations of MUNC13-4 and the cytotoxicity of MUNC13-4-deficient cytotoxic T lymphocytes (CTL) were analysed in 16 Japanese families with non-FHL2 subtype. RESULTS: Five new mutations of the MUNC13-4 gene were identified in six families. The mutations were in the introns 4, 9, and 18, and exons 8 and 19. Two families had homozygous mutations, while the remaining four had compound heterozygous mutations. Cytotoxicity of MUNC13-4 deficient CTL was low compared with control CTL, but was still present. Clinically, the onset of disease tended to occur late; moreover, natural killer cell activity was not deficient in some FHL3 patients. CONCLUSIONS: MUNC13-4 mutations play a role in the development of FHL3 through a defective cytotoxic pathway.

Adult Onset Asthma and Periocular Xanthogranuloma (AAPOX), a Rare Entity With a Strong Link to IgG4-Related Disease: An Observational Case Report Study.

Adult onset asthma and periocular xanthogranuloma (AAPOX) is a rare non-Langerhans histiocytosis characterized histopathologically by a periocular infiltration of foamy histiocytes and Touton giant cells. Benign hyperplasia with plasma cell infiltration is classically described in eyelids or lymph nodes of AAPOX patients. It is also a characteristic feature of IgG4-related disease (IgG4-RD), a new entity defined by an IgG4-bearing plasma cell infiltration of organs.To determine if AAPOX syndrome shares clinical, biological, and histopathological characteristics with IgG4-RD, we used the comprehensive clinical diagnostic criteria for IgG4-RD in a retrospective case series of three consecutive patients with histologically-proven AAPOX. Patients who were diagnosed with AAPOX at a French academic referral center for orbital inflammation between November 1996 and March 2013 were enrolled. Biopsies from ocular adnexa or other organs were systematically reexamined. For each patient, clinical and serological data, radiologic findings, and treatment were retrospectively analyzed.Two AAPOX patients fulfilled all of the diagnostic criteria for a definite IgG4-RD. One patient who lacked the serological criteria fulfilled the criteria of a probable IgG4-RD.These 3 cases of AAPOX patients fulfilled the IgG4-RD comprehensive clinical diagnostic criteria. To our knowledge, this is the first observational case report study to clearly show a strong relationship between IgG4-RD and AAPOX syndrome.