Canine macrophages can like human macrophages be in vitro activated toward the M2a subtype relevant in allergy.

The M2a subtype of macrophages plays an important role in human immunoglobulin E (IgE-mediated allergies) and other Th2 type immune reactions. In contrast, very little is known about these cells in the dog. Here we describe an in vitro method to activate canine histiocytic DH82 cells and primary canine monocyte-derived macrophages (MDMs) toward the M2a macrophages using human cytokines. For a side-by-side comparison, we compared the canine cells to human MDMs, and the human monocytic cell line U937 activated towards M1 and M2a cells on the cellular and molecular level. In analogy to activated human M2a cells, canine M2a, differentiated from both DH82 and MDMs, showed an increase in CD206 surface receptor expression compared to M1. Interestingly, canine M2a, but not M1 derived from MDM, upregulated the high-affinity IgE receptor (FcεRI). Transcription levels of M2a-associated genes (IL10, CCL22, TGFß, CD163) showed a diverse pattern between the human and dog species, whereas M1 genes (IDO1, CXCL11, IL6, TNF-α) were similarly upregulated in canine and human M1 cells (cell lines and MDMs). We suggest that our novel in vitro method will be suitable in comparative allergology studies focussing on macrophages.

Reactive T cells by flow cytometry distinguish Hodgkin lymphomas from T cell/histiocyte-rich large B cell lymphoma.

BACKGROUND: Classical Hodgkin lymphoma (CHL), nodular lymphocyte predominant Hodgkin lymphoma (NLPHL), and T-cell/histiocyte rich large B-cell lymphoma (T/HRLBCL) are B-cell lymphomas in which tumor cells are rare as compared with the background reactive infiltrate. We hypothesized that characterization of the reactive infiltrates can provide information to help diagnose these lymphomas. METHODS: Lymphocyte subsets by flow cytometry were analyzed for 27 NLPHL, 20 T/HRLBCL, 34 CHL, and 49 reactive lymph nodes (RLN). CD4+ T cells with bright expression of CD7 and CD45 (CD3+CD4+CD7(bright) CD45(bright) ), CD4:CD8 ratio, and percentage of T cells, B cells, NK cells, CD4+ T cells, CD8+ T cells, T cells coexpressing CD4, and CD8 (CD4+CD8+), and plasma cells were measured. RESULTS: The CD3+CD4+CD7(bright) CD45(bright) T-cell population was present in the reactive infiltrate of CHL (76.5%) and T/HRLBCL (92.3%) but not in NLPHL (8.3%) or RLN (4.1%). In a separate analysis of 387 samples, the CD3+CD4+CD7(bright) CD45(bright) T-cell population was also observed in some CD10+ B-NHL. The mean percentage of CD4+CD8+ T cells was highest for NLPHL (11.7%) and differed significantly from T/HRLBCL, CHL, and RLN. Interestingly, the highest CD4:CD8 ratios were seen with T/HRLBCL. Finally, the percentage of B cells is decreased in T/HRLBCL relative to CHL and NLPHL. CONCLUSIONS: Differences in the reactive inflammatory infiltrate of CHL, NLPHL, and T/HRLBCL and can suggest these diagnoses. Additionally, in contrast to published studies, T/HRLBCL demonstrates both low and very high CD4 to CD8 T-cell ratios. © 2015 International Clinical Cytometry Society.

A rare case of concomitant tuberculosis of the nose, paranasal sinuses and larynx: clinical, histological and immunohistochemical aspects. A case report.

Extrapulmonary tuberculosis is a rare condition determined by Mycobacterium tuberculosis. It can affect any organ, and has a higher incidence with the increase of HIV infection, or in countries with high pulmonary tuberculosis. Diagnosis is difficult, mostly because of non-specific symptoms and a low rate of presentation for medical consult when symptoms do occur. Complete diagnosis is usually set by histological, immunohistochemical examinations, and also with Polymerase Chain Reaction (PCR) in selected cases. The authors present a case of concomitant tuberculosis of the nose, paranasal sinuses and subglottic larynx, without primary involvement of the lungs. The diagnosis was imposed by histological examination and immunostaining of probes obtained in surgery. The treatment was surgical debridement followed by specific antituberculosis medication.

Inhibitor of differentiation-4 (Id4) stimulates pigmentation in melanoma leading to histiocyte infiltration.

TGF-ß and the inhibitors of differentiation (Id) are linked. Smad7 and other TGF-ß inhibitors can potently suppress melanomagenesis; however, little work examining Ids has been reported in melanoma, particularly for Id4. Here, we report that Id4, but not Id2 or Id3 expression, surprisingly, activated robust melanin production in xenografts of previously amelanotic (lacking pigment) 1205Lu/Smad7 (S7) cells. Fontana-Masson stain and de-novo expression of MART-1 and tyrosinase proteins confirmed melanin production. Additionally, pigment-laden CD163+ mouse histiocytes with areas of extensive necrosis were found throughout S7/Id4 tumors, but not in parental 1205Lu, S7/Id2 or S7Id3-derived tumors. Mechanistic investigation revealed increased nuclear M-microphthalmia-associated transcription factor (MITF) and MART-1 promoter activation following Id4 expression in 1205Lu and WM852 melanoma cells, suggesting broader implications for Id4 in melanin synthesis. In human tumors, melanin colocalized with Id4 expression establishing a correlation. Current chemotherapeutics for melanoma are only marginally effective. Immunotherapy provides the most promise, yet the role of innate immunity is poorly understood. Here, TGF-ß suppression followed by Id4 expression results in extensive melanin synthesis and robust histiocyte recruitment following tumorigenesis, a novel role for Id4. Our results suggest that TGF-ß suppression coupled with pigment overproduction triggers an innate immune response resulting in tumor necrosis.

Nonmarrow hematopoiesis occurs in a hyaluronic-acid-rich node and duct system in mice.

A hyaluronic-acid-rich node and duct system (HAR-NDS) was found on the surface of internal organs of mice, and inside their blood and lymph vessels. The nodes (HAR-Ns) were filled with immune cells of the innate system and were especially enriched with mast cells and histiocytes. They also contained hematopoietic progenitor cells (HPCs), such as granulocyte-macrophage, erythroid, multipotential progenitors, and mast cell progenitors (MCPs). MCPs were the most abundant among the HPCs in HAR-Ns. Their frequency was fivefold higher than that of the MCPs in bone marrow. In addition, the system contained pluripotent stem cells (PSCs) capable of producing CD45(-)Flk1(+) hemangioblast-like cells, which subsequently generated various types of HPCs and differentiated blood cells. Although HAR-Ns did not appear to harbor enough number of cells capable of long-term reconstitution or short-term radioprotection of lethally irradiated recipients, bone marrow cells were able to engraft in the HAR-NDS and reconstitute hematopoietic potentials of the system. PSCs and HPCs were consistently found in intravenous, intralymphatic, and intestinal HAR-ND. We infer that PSCs and HPCs reside in the HAR-ND and that this novel system may serve as an alternative means to traffic immature and mature blood cells throughout the body.

Lennert's lymphoma: clinicopathological profile of five cases.

BACKGROUND AND AIM: Lennert's lymphoma is a rare variant of peripheral T-cell lymphoma (PTCL) not otherwise specified (NOS) rich in epithelioid histiocytes. This study aims to analyze the clinical, morphologic, and immunophenotypic profile of cases of Lennert's lymphoma from our country and determines the utility of T-cell receptor (TCR) gene rearrangement in the diagnosis. MATERIALS AND METHODS: All cases diagnosed as Lennert's lymphoma during the period of January 2001 to August 2011 were included in this study. Hematoxylin and eosin (H and E) stained slides and immunohistochemistry results were analyzed and TCR gene rearrangement was performed. RESULTS: There were five cases of Lennert's lymphoma diagnosed in our institution during this period, which included two males and three females. All cases showed effacement of lymph node architecture by diffuse infiltration of small lymphoid T cells [CD3+, CD4+, CD8+, T-cell intracellular antigen 1 (TIA-1+), Granzyme B-] and clusters of epithelioid histiocytes throughout the lymph node and scattered large transformed cells (CD20-, CD30+, CD15-/+). TCR rearrangement was done in three cases by polymerase chain reaction (PCR) and showed the presence of a clonal T-cell population. CONCLUSIONS: Lennert's lymphoma constituted 0.11% of all non-Hodgkin lymphomas (NHLs) in our institution. Differentiation from classical Hodgkin's lymphoma is sometimes difficult by morphology and immunohistochemistry alone and TCR gene rearrangement was extremely useful in diagnosis.

Comparison of morphological changes in efferent lymph nodes after implantation of resorbable and non-resorbable implants in rabbits.

BACKGROUND: Magnesium alloys as biodegradable implant materials received much interest in recent years. It is known that products of implant degradation can induce several types of immune response. Hence, the aim of this study was to examine the morphological changes of efferent lymph nodes after implantation of different resorbable magnesium alloys (MgCa0.8, LAE442) in comparison to commercially available resorbable (PLA) and non-resorbable (titanium) implant materials as well as control groups without implant material. METHODS: The different implant materials were inserted intramedullary into the rabbit tibia. After postoperative observation periods of three and six months, popliteal lymph nodes were examined histologically and immunhistologically and compared to lymph nodes of sham operated animals and animals without surgery. Haematoxylin and eosin staining was performed for cell differentiation. Mouse anti-CD79α and rat anti-CD3 monoclonal primary antibodies were used for B- and T-lymphocyte detection, mouse anti-CD68 primary antibodies for macrophage detection. Evaluation of all sections was performed applying a semi quantitative score. RESULTS: The histological evaluation demonstrated low and moderate levels of morphological changes for both magnesium alloys (LAE442 and MgCa0.8). Higher than moderate values were reached for titanium in sinus histiocytosis and histiocytic apoptosis (3 months) and for PLA in histiocytic apoptosis (3 and 6 months). The immune response to all investigated implants had a non-specific character and predominantly was a foreign-body reaction. LAE442 provoked the lowest changes which might be due to a lower degradation rate in comparison to MgCa0.8. Therewith it is a promising candidate for implants with low immunogenic potential. CONCLUSION: Both examined magnesium alloys did not cause significantly increased morphological changes in efferent lymph nodes in comparison to the widely used implant materials titanium and PLA. LAE442 induced even lower immunological reactions. Therewith MgCa0.8 and especially LAE442 are appropriate candidates for biomedical use.

A comparative immunohistochemical evaluation of CD68 and TRAP protein expression in central and peripheral giant cell granulomas of the jaws.

BACKGROUND: Giant cell granulomas of the jaws are lesions that arise either peripherally in periodontal ligament and mucoperiosteum or centrally in the bone. The aim of this study was to evaluate expression of CD68 and tartrate-resistant acid phosphatase (TRAP) proteins in multinucleated giant cells and mononuclear cells. METHODS: Formalin-fixed and paraffin-embedded tissue section of 20 specimens of central giant cell granuloma and 20 cases of peripheral giant cell granuloma were immunohistochemically analyzed for CD68 and TRAP proteins expression rate using Biotin-Streptavidin method. RESULT: In central giant cell granuloma, more than 99% of multinucleated giant cells were positive for TRAP antibody and about 90% were positive for CD68. In mononuclear cells of this lesion, 14% of cases were positive with TRAP antibody and 8% with CD68. In peripheral giant cell granuloma, TRAP antibody was positive in 99% of giant cells and in 13% of mononuclear cells. A proportion of 97% of giant cells and 6% of mononuclear cells reacted positively with CD68. CONCLUSION: Immunohistochemical evidence of this study shows that giant cells and a group of mononuclear cells of stroma in both peripheral and central giant cell granuloma express TRAP antibody severely that is specific for osteoclast. Also, these cells are positive reactive to CD68, which is the macrophage marker and therefore it can be mentioned that giant cells are osteoclast, although their origins are macrophagic/monocytic or their precursors, and maybe mononuclear cells in stroma have a role in formation of giant cells.

Understanding organ dysfunction in hemophagocytic lymphohistiocytosis.

OBJECTIVE: This review aims to help critical care clinicians maintain a high level of suspicion regarding the diagnosis of Hemophagocytic Histiolymphocytosis (HLH). It describes the clinical and laboratory features of HLH, outlines its pathophysiology and reviews the most frequent etiologies related to HLH. Prognostic factors and therapeutic options are also reported. DATA SOURCES: Review of the literature. RESULTS: The diagnosis of HLH relies on the association of clinical abnormalities and hemophagocytosis in bone marrow, spleen, or lymph node specimens. Liver, pulmonary, renal, cardiac and skin involvement may occur at various degrees possibly leading to multiple organ failure. Three main etiologies can be found, namely infections, lymphoproliferative diseases, or connective tissue diseases. Immune deficiency is often retrieved. Mortality can be as high as 50%. Although clinically mimicking severe sepsis, HLH has a distinct pathophysiology on which specific therapy is based. Early diagnosis and treatment is mandatory to increase the chances of survival. CONCLUSION: The comprehensive management of severe HLH requires the involvement of a multidisciplinary team in order to determine the best therapeutic strategy and to identify the underlying cause.

Primary cutaneous histiocyte and neutrophil-rich CD30+ and CD56+ anaplastic large-cell lymphoma with prominent angioinvasion and nerve involvement in the forehead and scalp of an immunocompetent woman.

BACKGROUND: Cutaneous lymphomas co-expressing CD56 and CD30 are very rare. They share a clinicopathological overlap with natural killer- (NK)/T-cell lymphomas and anaplastic large-cell lymphomas (ALCLs), two entities with widely disparate clinical behavior. METHODS: We present a case of an immunocompetent 57-year-old Caucasian woman with a rapidly growing, angiodestructive and neuroinvasive primary cutaneous ALCL (PCALCL). The neoplastic population of large anaplastic CD30+ and CD56+ T cells was masked by a massive admixture of histiocytes and neutrophils. The partially ulcerated and pus-secreting tumor involved the forehead and scalp and was assessed as clinical stage IAE. RESULTS: After chemotherapy (cyclophosphamide, doxorubicin, vincristine, and prednisone), the patient achieved a complete remission. Additionally, high-dose chemotherapy with autologous peripheral blood stem-cell transplantation was administered as a consolidation of complete remission, in which she has remained for 6 years. CONCLUSIONS: This is the first CD30+ and CD56+ primary skin lymphoma to be reported on the head. The presented case carries a remarkable combination of clinicopathological features of PCALCL and NK-/T-cell lymphoma.

Growth characteristics of canine distemper virus in a new cell line CCT cells originated from canine malignant histiocytosis.

Canine distemper virus (CDV) growth and the morphological characterization were examined in a cell line established from a canine malignant histiocytosis (CCT cell line). The susceptibility of the CCT cells to 3 CDV strains, FXNO, YSA-TC and MD-77 was shown by detection of the antigen in the indirect fluorescent assay. After passaging 4 and 9 times through the CCT cells, only FXNO strain could produce the syncytia where demonstrated the antigens. Titers of 9 passaged viruses through the CCT cells showed slightly higher in the CCT cells than those in Vero cells. Morphological characterization of karyorrhexis and specific DNA ladder by extracted DNA electrophoresis indicated apoptosis in the CDV infected CCT cells.

Histiocytic subpopulations in the gastrointestinal tract: distribution and possible relationship to function.

The distribution of specific histiocyte subsets within the human gastrointestinal tract has not been extensively characterized. Our goal was to immunohistochemically evaluate the distribution and location of CD1a-positive, CD68-positive, and Factor XIIIa (FXIIIa)-positive histiocyte subsets within the normal gastrointestinal tract and attempt to relate distribution to possible function. Twenty-nine samples of normal esophagus, stomach, small bowel, large bowel, and anus were routinely processed and immunohistochemically stained with antibodies to CD68, CD1a, and FXIIIa. The distribution and histologic location of histiocyte subsets were qualitatively analyzed. CD1a-positive cells were seen exclusively within anal and esophageal squamous mucosa. CD68 positive histiocytes were present in lamina propria and submucosa throughout the gastrointestinal tract and in Peyer patches. FXIIIa-positive histiocytes were also abundant in lamina propria and submucosa throughout the gastrointestinal tract, particularly around pericryptal sheaths and in parafollicular regions surrounding Peyer patches. Our results showed that there are distinct subpopulations of gastrointestinal histiocytes, and that distribution varies according to both cell type and site. Because Langerhans cells are epidermal antigen processing/presentation cells, their exclusive presence in squamous mucosa suggests an analogous function there. The prominence of both CD68 and FXIIIa-positive cells surrounding glandular pericryptal sheaths suggests that they are important to immune function at this mucosal interface and may play a role in communication between glands and lamina propria. In addition, the presence of specific histiocyte subsets within Peyer patches and para-follicular regions suggests that they are involved in different aspects of antigen processing associated with gut lymphoid tissue. Further studies are needed to explore the relation between specific histiocyte subsets and gastrointestinal disease processes.

Allergic granulomatosis and angiitis in the absence of asthma and blood eosinophilia: a rare presentation of limited Churg-Strauss syndrome.

Allergic granulomatosis and angiitis, also known as Churg-Strauss syndrome (CSS), is an uncommon vasculitis of unknown etiology. We report a 21-year-old male patient with fatigue, dry cough, and progressive dyspnea. He had no history of asthma or eosinophilia. Thorax computed tomography showed bullous/cystic areas with thin walls in varying sizes (5-15 mm). Histopathological examination of the open lung biopsy revealed granulomatous infiltration with histiocytes and eosinophilic leukocytes. This extremely rare variant of CSS is discussed.

Congenital Rosai-Dorfman disease without lymphadenopathy.

Rosai-Dorfman disease (RDD) is a rare histiocytic proliferative disorder with massive lymphadenopathy. We here describe RDD of a neonate who presented with paleness and hepatosplenomegaly but not lymph-node swelling. Routine laboratory studies showed anemia, thrombocytopenia, and an elevated value of gamma-glutamyl transpeptidase. Histological examination of the liver revealed a proliferation of histiocytes with abundant eosinophilic cytoplasm, which were positive for S-100 protein and CD68 but not CD1a and did not reveal Birbeck granules. Radiological studies showed hepatosplenomegaly and a narrowing of the hepatic vein, which might have contributed to hypersplenism resulting in anemia and thrombocytopenia. This case is thought to be congenital RDD without lymphadenopathy.

Microphthalmia transcription factor in the immunohistochemical diagnosis of metastatic melanoma: comparison with four other melanoma markers.

The diagnosis of metastatic malignant melanoma (MMM) may be difficult in surgical pathology, often complicated by the unpredictable spread of this tumor and its great variability on histologic evaluation. Traditionally used immunohistochemical markers on melanomas are insufficient because of either a relative lack of specificity (S100 protein) or variably reported sensitivity (HMB45). Information about some newer markers, such as tyrosinase (TYR) and Melan A, is more limited. Recently, based on the study of a small number of tumors, it was suggested that microphthalmia transcription factor (MITF) is 100% sensitive in the identification of metastatic melanoma. In the current study, we compared the diagnostic usefulness of MITF with that of four other markers in 266 cases of conventional metastatic melanomas from different sites, 33 cases of desmoplastic melanomas, and 1 case of melanoma with rhabdoid features. The specificity of MITF was evaluated by using a representative sample of control tumors. Microphthalmia transcription factor with nuclear positivity was seen in 235 of 266 cases of conventional MMM (88%), usually in more than 30% of tumor cells. However, some melanomas had only foci of MITF- and TYR-positive cells, whereas the majority of cells were generally S100 protein-positive. Only 1 of 30 desmoplastic melanomas (3%) had MITF-positive cells, representing epithelioid foci resembling conventional melanoma. Two cases had TYR in a similar pattern; all were HMB45-negative. One metastatic melanoma with rhabdoid features was negative for MITF and other markers except the S100 protein. Half of the S100 protein negative conventional melanomas (6 of 12) were MITF-positive, whereas 4 of 20 (20%) TYR-negative tumors had reactivity for MITF. The percentages of positive cases of MMM (10% or more tumor cells positive) diagnosed with the four other markers in descending order were 90% (S100 protein and TYR), 78% (melan-A), and 66% (HMB45). Microphthalmia transcription factor appeared to be specific, because significant reactivity was not found in 112 carcinomas, 20 lymphomas, 20 angiosarcomas, 20 fibrous histiocytomas, and 20 malignant peripheral nerve sheath tumors. However, positive nuclei were found focally among reactive histiocytes, especially in osteoclasts, epithelioid histiocytes, and sporadic other histiocytes. Microphthalmia transcription factor may be a valuable addition to the marker panel used in diagnosing melanoma, in combination with S100, TYR, and the other markers, but it is not present in cases of desmoplastic melanomas.