Immunohistochemical analysis of langerin in langerhans cell histiocytosis and pulmonary inflammatory and infectious diseases

Pulmonary Langerhans cell histiocytosis (LCH) is an idiopathic condition affecting predominantly adult smokers. Histologically, LCH is characterized by a nodular, interstitial proliferation of Langerhans cells around the distal airways with associated eosinophils, lymphocytes, and macrophages. Associated findings, such as fibrosis, emphysematous change, and bronchiolitis can be reminiscent of other interstitial lung diseases. The markers CD1a and S100 have traditionally been used to distinguish LCH from other processes. Little is known about expression of the Langerhans cell-specific lectin, langerin, in pulmonary diseases. We examined the expression patterns of S100, CD1a, and langerin in LCH and other interstitial, inflammatory, and infectious processes in cases retrieved from the files at Brigham and Women's Hospital Department of Pathology. Immunoreactivity was scored according to the number of cells staining per high power field (400x) in areas of highest density, averaged over 4 fields. Cases diagnosed as LCH based on histomorphology and positive CD1a and S100 staining demonstrated strong langerin positivity in lesional tissue. All cases of LCH contained greater than 30 langerin and CD1a positive cells per high power field (HPF), with a mean of >100 cells per HPF, in lesional tissue. Of the other interstitial processes examined, only usual interstitial pneumonia demonstrated increased number of Langerhans cells within epithelium and interstitium (mean 14 cells per HPF) as compared with normal lung (mean 6 cells per HPF). Langerin and CD1a serve as specific diagnostic markers in distinguishing LCH from other interstitial and inflammatory processes.     

Distribution of Langerhans cells and HLA class II molecules in prostatic carcinomas of different histopathological grade

We have investigated Langerhans cell (LC) distribution in 38 prostatic carcinomas, of various degrees of differentiation, by immunohistochemistry with a polyclonal anti-S-100 serum, furthermore evaluating the expression of HLA class II-DR by neoplastic cells using a monoclonal antibody (MoAb) that reacts with a monomorphic determinant in formalin-fixed paraffin-embedded tissue. Antiserum to S-100 protein identified LCs mostly in carcinomas ranging from grade 1 to grade 2, while LCs were inconspicuous in grade 4 and virtually absent in grade 5 cancers. Moreover, sections stained with the anti -HLA-DR MoAb displayed an immunoreactivity, both cytoplasmic and apical, especially confined to neoplastic glands of low grade (1-2) carcinomas. Although we did not find a direct correlation between the two parameters under investigation and lymphoid infiltrate, we were able to document an increased number of HLA class II-positive interstitial cells in low-grade carcinomas, corresponding mostly to macrophages. Our results indicate that LC number is inversely correlated to the histopathological grade and directly to the expression of HLA class II-DR molecules by tumor cells; we believe that this might be important in understanding the more favorable biological behavior of low-grade prostate carcinomas as opposed to the higher grades, since LCs and HLA class II molecules may provide a means of eliciting the immune response, both LCs and epithelial cells expressing HLA class II molecules being capable of direct antigen presentation to immune cells. In this context macrophages might play a primary role in controlling tumor progression. To the best of our knowledge this is the first time that an attempt is made to correlate LCs and HLA class II expression to histopathological grading of prostatic carcinomas. We would also suggest that the presence of LCs and HLA class II molecules, either singly or in combination, in carcinoma of the prostate represents a good prognostic indicator, being constantly associated with the clinically less aggressive low-grade tumors. The evaluation of these two parameters might prove useful in the assessment of intermediate grades where no valid histologic criteria have been found to predict the clinical course of the disease.     

Perturbation of epidermal Langerhans cells in immunosuppressed human renal allograft recipients

As an initial attempt to gain a better understanding of the basis for the increased incidence of ultraviolet-light-related skin cancer in chronically immunosuppressed human renal allograft recipients, we have compared both morphological and functional characteristics of epidermal Langerhans cell (LC) populations present in the forearm skin of nine such patients with those of age, sex, and race-matched controls. The LC surface densities in vacuum-induced blister-derived epidermal sheets taken simultaneously from extensor and flexor forearm skin of the patients were significantly lower than those observed in the controls. The most abnormal LC densities seen were in the patients' extensor forearm skin. Likewise there were disturbances in LC distribution and morphology that were most marked in the extensor forearm skin of patients. Differences in the alloantigen-presenting capacity of LCs present in epidermal cell suspensions prepared from patient and control forearm skin were also noted--however, these differences were not as great as were the LC density differences. The alloantigen-presenting capacity of patients' LCs was depressed proportionately more than was the alloantigen presenting capacity of their peripheral blood mononuclear cells. These results demonstrate that the LC population is clearly perturbed in human renal allograft recipients and that this perturbation is greatest in a sun-exposed region of skin.     

Resection of a Langerhans cell histiocytosis granuloma of the hypothalamus: case report

The natural course and optimal treatment for isolated hypothalamic Langerhans cell histiocytosis (LCH) are unknown. We describe an adult female in whom total resection of a hypothalamic LCH granuloma was performed 12 years after transphenoidal resection of a pituitary adenoma. A retrospective review of the histological specimen of the first operation revealed CD1a positive cells characteristic of LCH along with a plurihormonal adenoma 12 years earlier. No other manifestations of LCH were found and MRI of the brain at the last follow-up 4 years after surgery did not show any recurrent or additional lesion. The diagnosis of isolated hypothalamic LCH is only possible by biopsy and our case demonstrates the feasability of a gross total resection in certain cases.     

Langerhans Cell Histiocytosis: Diagnosis on Thyroid Aspirate and Review of the Literature

Thyroid gland involvement by Langerhans cell histiocytosis is extremely rare. A 35-year-old woman with a history of a suprasellar mass previously diagnosed as a ganglioglioma and complicated by diabetes insipidus, hypogonadotropic hypogonadism, and central hypothyroidism presented with acute onset of neck enlargement. On ultrasound examination, almost the entire thyroid appeared replaced by abnormal lobulated hypoechoic tissue with increased vascularity. Fine needle aspiration (FNA) of the thyroid was performed and revealed singly scattered and loosely cohesive large cells with abundant cytoplasm, including some with irregular nuclear contours and nuclear grooves. No thyroid follicular cells were noted. Based on the cytomorphologic findings and ancillary studies (immunohistochemistry and flow cytometry analysis) a cytological diagnosis of “positive for neoplastic cells” with features suggestive of monocytic/histiocytic origin, possibly Langerhans cell histiocytosis (LCH) was rendered. Following FNA, the patient underwent an incisional thyroid biopsy that confirmed the cytological impression of LCH. In light of the new diagnosis of LCH, the prior suprasellar mass biopsy slides were re-reviewed and rare cells suspicious for LCH were observed. Appropriate treatment for systemic LCH was initiated successfully. This case demonstrates that the presence of enlarged and loosely cohesive cells, especially those with irregular nuclear contours, in thyroid FNA specimens should raise suspicion for LCH. The diagnosis of LCH in FNA specimens is challenging. Additional material should be allocated for ancillary studies to confirm the morphological impression. In our case, not only was the thyroid FNA crucial in diagnosing LCH, but instrumental in initiating a thorough diagnostic work-up for multisystem involvement and thus unmasking the true etiology of the patient’s suprasellar mass and associated endocrinopathies.     

Langerhans cell histiocytosis of the cervical spine: a single institution experience in four patients

When Langerhans cell histiocytosis (LCH) occurs at critical sites, such as in the cervical spine, there is a substantial risk for morbidity. Therefore, reports on clinical experiences with those patients remain important. We summarize the history of four patients with unifocal LCH at the cervical spine. All four patients received a biopsy to prove the histopathological diagnosis of LCH by demonstration of CD1a+cells. They were treated with oral prednisolone. All patients recovered completely and kept a normal function of the cervical spine. No reactivation of the disease occurred with an observation time of 3.4-7.3 years. This report contributes to the clinical experience for the treatment of LCH at critical sites.     

Preliminary technical report. Epitope-defined monoclonal antibodies against type-IV collagen for diagnosis of Alport's syndrome

Background. Alport's syndrome can be diagnosed by staining the &agr;5 chain of type IV collagen in kidney biopsy specimens with a monoclonal antibody. Because antibodies already established against the &agr;5 chain require denaturation treatment of cryostat sections to expose their epitopes. To save time and effort for staining, a new epitope-defined monoclonal antibody whose epitope is initially exposed on the surface of the molecule was established. Methods. Two monoclonal antibodies against the triple-helical domains of the type IV collagen &agr;2 and &agr;5 chains were established with synthetic peptides as immunogens by the rat lymph node method. Their epitope were EAIQP at the positions of 675-679 of the &agr;2 chain, and IDVEF at the positions of 251-255 of the &agr;5 chain respectively. They were purified with synthetic peptide-coupled affinity columns, and then conjugated with Texas red and FITC, respectively. Results. The mixture of fluorochrome-conjugated antibodies was able to detect the distribution of the &agr;2 and &agr;5 chains in the normal and Alport kidney and skin by direct immunofluorescence staining with and without denaturation treatment of the sections. Conclusions. The direct double immunofluorescence staining of kidney and skin cryostat sections with the fluorochrome-conjugated antibodies is useful, reliable, and convenient for diagnosis of Alport's syndrome. Keywords: Alport's syndrome; diagnosis; kidney biopsy; monoclonal antibodies; skin biopsy; type IV collagen      

Langerhans cell histiocytosis of the rib in adult male

A 57-year-old man was admitted to our hospital with an abnormal shadow on chest X-ray film. Computed tomography (CT) scanning demonstrated a low-density, destructive mass on the right 8th rib. The maximum standardized uptake value of the tumor measured by positron emission tomography (PET) was 2.9, indicating malignancy. Wide resection of the tumor, including the right 8th rib and the 7th to 8th intercostal muscle, was performed. Chest wall reconstruction was achieved with Composix Mesh. The histologic findings revealed proliferation of histiocytes and eosinophil infiltration. No malignant cells were detected in the tumor. Histiocytes stained for S-100 protein and CD1a, compatible with a diagnosis of Langerhans cell histiocytosis (LCH). LCH in the ribs is very rare and difficult to diagnose using CT or PET. Tumor biopsy or resection is needed to diagnose LCH.     

Phenotype and functional identity of GM-CSF-independent dendritic cells generated by long-term propagation of DC progenitor cells in bone marrow cells and skin Langerhans cells

Evidence is provided that dendritic cells (DC) generated by either long-term bone marrow cell (BMC) culture with Flt3L and interleukin-6 (IL-6), or after short-term BMC culture with granulocyte macrophage-colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4), contain heterogeneous cell populations of admixed DC and Mphi, regardless of the cytokine source. By employing GM-CSF-independent culture systems with the aid of Flt3/Flk-2 ligand and IL-6 and phenotypic characterization of BMC-derived DC and skin Langerhans cells (LC), revealed similar phenotypes. Furthermore, CD103 (OX62), which is widely used for rat DC separation, was found to be insufficient to enrich DC, due to downregulation of the marker. In this regard, the most efficient selection of rat DC, was obtained by CD161a (NKR-P1A), a member of the C-type lectin family. Despite the phenotypic similarity with BMC-derived DC, the nucleus of LC showed a distinct morphology. A large population of DC generated by Flt3L/IL-6 from GM-CSF receptor-deficient mice by do not express NK1.1 (NKR-P1B and NKR-P1C). The profiles for BMC-derived DC were the same as for skin Langerhans cells.     

Solitary Langerhans Histiocytosis of the Thyroid Gland: A Case Report and Literature Review

Langerhans cell histiocytosis (LCH) is a rare disease of antigen presenting cells, with an incidence rate of 4.0–5.4 per 1 million individuals. The most common endocrinological manifestation of classical LCH is associated with the posterior pituitary, presenting as Diabetes Insipidus. However, LCH can affect multiple organs and classification is based on the body system involvement. The disease is confirmed by electron microscopy or immunohistochemical reactivity of histiocytes to CD1a and/or S100. LCH rarely involves the thyroid gland, and management of such disease is controversial. Current literature documents 65 English language reported cases of LCH involving the thyroid gland. We present an unusual case of LCH of the thyroid gland, with variable diagnoses on fine needle aspiration (FNA) cytology, and literature review of all English reported cases.     

Immunohistochemical expression of Langerin in Langerhans cell histiocytosis and non-Langerhans cell histiocytic disorders

Langerin is a type II transmembrane C-type lectin associated with the formation of Birbeck granules in Langerhans cells. Langerin is a highly selective marker for Langerhans cells and the lesional cells of Langerhans cell histiocytosis. Although Langerin protein expression in Langerhans cell histiocytosis has been previously documented, the specificity of Langerin expression as determined by immunohistochemistry in the context of other histiocytic disorders has not been well established. In the present study, Langerin immunoreactivity was examined in a series of histiocytic disorders of monocyte/macrophage and dendritic cell derivation to assess the specificity and utility of Langerin as a diagnostic marker for Langerhans cell histiocytosis. Immunohistochemical expression of CD1a was also evaluated for comparison. Seventeen cases of Langerhans cell histiocytosis and 64 cases of non-Langerhans cell histiocytic disorders were examined. Langerin and CD1a were uniformly expressed in all cases of Langerhans cell histiocytosis, with the exception of one case that was positive for Langerin and negative for CD1a. Among the non-Langerhans cell histiocytic disorders evaluated, focal Langerin immunoreactivity was observed only in 2 of 10 cases of histiocytic sarcoma. All non-Langerhans cell histiocytic disorders showed no expression of CD1a. Langerin expression seems to be a highly sensitive and relatively specific marker of Langerhans cell histiocytosis. Immunohistochemical evaluation of Langerin expression may have utility in substantiating a diagnosis of Langerhans cell histiocytosis and separating this disorder from other non-Langerhans cell histiocytic proliferations.     

Immunopathology of early graft-versus-host disease--a prospective study of skin, rectum, and peripheral blood in allogeneic and autologous bone marrow transplant recipients.

The immunopathological appearances of skin and rectum in 64 autologous and allogeneic recipients were determined before and after bone marrow transplantation. Patients who developed acute graft-versus-host disease were biopsied as soon as a clinical diagnosis was made. At the same time peripheral blood samples were collected for comparative analysis. Immunohistological and morphometric techniques were employed using a panel of monoclonal antibodies to T lymphocytes and subsets, B lymphocytes, natural killer cells, macrophages, and Langerhans cells. A reduction in the CD4/CD8 ratio after BMT was seen in skin and rectal biopsies from both autologous and allogeneic recipients with or without GVHD. The same pattern was observed in blood samples taken at the same time. Langerhans cells were reduced in the skin in all patients after BMT, probably by the conditioning regimen. Only a few cells expressing activation or natural killer cell markers were present and there were no changes observed in the macrophage population. This study has provided no evidence to implicate either CD4- or CD8-positive T lymphocytes as the initiators of the cellular damage in acute GVHD. The distribution of lymphocyte subsets in the blood was similar to that in the tissues, suggesting that the tissue changes reflect the pattern of lymphocyte repopulation after BMT and may have little bearing on the pathogenesis of GVHD.     

Characterization of CXCL13+ neoplastic t cells in cutaneous lesions of angioimmunoblastic T-cell lymphoma (AITL)

Skin manifestations of angioimmunoblastic T-cell lymphoma (AITL) are frequent, sometimes as first manifestations of the disease. In the absence of a specific marker for neoplastic cells, diagnosis of AITL in skin biopsies is often difficult. CD10 and CXCL13 have been recently recognized as characteristic markers of AITL, but have not been yet investigated in the skin. We analyzed 15 skin biopsies from 8 patients with AITL having skin manifestations and compared them to 14 skin biopsies from patients with various cutaneous lymphocytic infiltrates. A few CD10 lymphocytes were found in only 2 samples of the AITL group, the identification of which was hampered by the presence of a dermal CD10 cell population with dendritic features. By contrast, CXCL13 lymphoid cells were identified in most AITL cutaneous biopsies (n=12, 80%), whereas, absent in all samples from control cases. Among 12 biopsies with CXCL13 cells, cutaneous involvement by AITL was suspected in only 5 on the basis of light microscopy and classic immunophenotyping. In another case, a diagnosis of cutaneous marginal zone B-cell lymphoma had been proposed. In conclusion, this study shows that neoplastic AITL CXCL13 T cells localize in the skin and that accurate diagnosis of AITL lesions can be done in skin specimens using CXCL13 immunostaining on paraffin-embedded tissues.     

Langerhans cell histiocytosis: a primary viral infection of bone? Human herpes virus 6 latent protein detected in lymphocytes from tissue of children

To better understand the etiology of Langerhans cell histiocytosis (LCH), the authors analyzed tissue from 35 children diagnosed with LCH for the presence of viral proteins and DNA by immunohistochemistry (IHC) and in situ hybridization (ISH). Eighteen control biopsies were obtained from patients without LCH. Confirmatory ISH was randomly performed on four positive and two negative cases determined by IHC. Twenty-five (71.4%) tissue samples with LCH involvement stained by IHC with the 101-kDa antibody against human herpesvirus-6 (HHV-6). None were positive with antibodies against the p41/38 or gp110 viral proteins. Five (27.7%) positive control tissues demonstrated presence of the 101-kDa viral protein in a similar fashion. The difference in the prevalence of HHV-6 in LCH-positive tissues (25/35) when compared with control tissues from patients without LCH involvement (5/18) was statistically significant. ISH confirmed the IHC in all six tissues tested. These findings demonstrate an association between HHV-6 and LCH, suggesting a role for the HHV-6B in the etiology of this disease.     

Recurrence of Langerhans cell histiocytosis in the graft after pediatric liver transplantation

Two girls were diagnosed with Langerhans cell histiocytosis (LCH) at the age of 16 and 7 months and developed end stage chronic liver disease related to LCH-induced sclerosing cholangitis at 28 and 8 months, respectively. They received liver transplants at 34 and 14 months of age. Five months post-orthotopic liver transplantation (OLT) one of the patients developed posttransplant lymphoproliferative disease, successfully treated with a combination of surgery and reduction of immunosuppression. Fourteen months post-OLT she developed diabetes insipidus, bilateral ear discharge, and new osteolytic lesions. After transplantation both girls had mild skin reactivations of LCH, requiring minimal steroid increments. At 60 and 5 months post-OLT intrahepatic LCH recurrence was diagnosed on the basis of abnormal biliary enzymes and presence of Langerhans cells in the grafts. Initial cholangiography in both patients was unremarkable. LCH activity was controlled by maintenance chemotherapy with vinblastine, etoposide, and prednisolone. Ten months after reappearance of LCH in the liver graft a follow-up cholangiography in one of the girls demonstrated a low grade cholangiopathy. Residual elevation of liver enzymes probably represents an ongoing pathogenic process.     

Immunologic responses in vascularized and nonvascularized skin allografts

The skin is a protective interface between internal organs and the environment; it is the largest tissue of the human body. However, the skin does not serve merely as a physical barrier. It is also an active immune organ, traversed by a network of lymphatic and blood vessels. This immunologic structure contains immunologic cells such as T lymphocytes, Langerhans cells (LCs), dendritic cells, and keratinocytes. Langerhans cells represent the cutaneous counterpart of dendritic cells. LCs not only act as professional antigen-presenting cells to induce antigen-specific T cells for adaptive immune responses, but they also initiate a cascade of innate immune responses by antigenic stimulus such as transplant tissue. In transplantation immunology, either donor or recipient LCs fulfill an important mission in rejection or acceptance of donor tissue. Vascularized or nonvascularized skin allografts may create an immunologic response through different pathways. In both transplant models, skin diameter may change antigenic load, thereby determining rejection or acceptance response. This article discusses the effects of the cellular component in the skin immune system on immunologic responses of vascularized or nonvascularized skin allografts and describes the differences between the two immunologic cascades.     

Langerhans Cell Histiocytosis of the Temporal Bone

Langerhans cell histiocytosis involving the temporal bone region is uncommon and can resemble malignant neoplasms on imaging due to high cellularity. Although recognizing the presence of sharp margins with beveled-edges can be helpful, tissue sampling is often necessary for confirming the diagnosis. Cytology classically demonstrates kidney-bean shaped nuclei within the Langerhans cells and immunohistochemical staining is positive for S-100, peanut agglutinin (PNA), MHC class II, CD1a, and Langerin (CD 207). These features are exemplified in this sine qua non radiology–pathology correlation article.     

Influence of major-histocompatibility-complex-compatible and incompatible Langerhans cells on the survival of H-Y-incompatible skin grafts in rats

BN male trunk skin grafts, the Langerhans cells (LC) of which have been replaced with major histocompatibility complex (MHC)-incompatible Lewis female cells, survive longer on BN female rats than BN male trunk skin grafts bearing BN female LC. Evidence is presented that the privilege afforded these grafts is a consequence of MHC restriction. Thus, supplanting the native LC population of BN male trunk skin grafts with MHC-compatible Lewis.1N female cells has no affect on their survival on BN female rats. Evidence is also presented that H-Y-incompatible isografts deficient in MHC-compatible LC induce tolerance of H-Y.     

CD20+ T-cell lymphoma: clinicopathologic analysis of 9 cases and a review of the literature

Rare cases of CD20+ T-cell lymphoma (TCL) have been reported, but the clinicopathologic spectrum of this disorder is not known. We identified 9 cases of CD20+ TCL diagnosed at our institution and 26 additional cases through a search of the English language literature. Among current cases, there were 7 men (ages 71 to 81, median 75 y) and 2 women (ages 36 and 37 y). Five patients presented with predominantly nodal disease (localized in 3 and widespread in 2 cases) and 4 patients presented with purely extranodal disease involving the parotid glands, skin, or small intestine. CD20 was uniformly and strongly expressed in 5 cases and dimly expressed or present on a subset of neoplastic cells in 4 cases. The proportion of CD20+ T cells changed over time in 3 cases. Three cases fulfilled diagnostic criteria for clinicopathologically defined subtypes of TCL (2 mycosis fungoides; 1 enteropathy-type TCL), whereas 6 were peripheral TCL unspecified with variable cytomorphology, T-cell immunophenotype, and sites of involvement. In 8 of 9 cases, a clonal T-cell population was identified by molecular genetic analysis. Among 8 cases with clinical follow-up, 5 behaved aggressively with death from disease within 3 years of diagnosis in 4 cases (median survival: 11 mo, range: 1 to 35 mo), and recurrent disease at 10 months in 1 case; 1 patient died of an EBV+ B-cell lymphoma (BCL) 66 months after the original diagnosis; in the remaining 2 cases, patients were alive and undergoing treatment (follow-up: 4 and 18 mo). Historical cases showed similar clinicopathologic variability. CD20+ TCL is rare, and clinically and pathologically heterogeneous. When CD20 expression is present in TCL, it may be dimmer than that of normal B cells, suggesting neoplastic transformation of a normal CD20dim+ T-cell subset. Cases of CD20+ TCL in which the proportion of CD20+ cells changes over time may reflect aberrant expression of CD20, possibly as an activation marker, by neoplastic T cells. CD20+ TCL may cause diagnostic difficulty, particularly in cases that clinically and pathologically mimic BCL. Knowledge of the unusual phenomenon of CD20 expression in TCL, in conjunction with careful morphologic analysis, the use of a panel of antibodies, and molecular genetic studies, is important in avoiding a misdiagnosis of BCL.     

Langerhans cell histiocytosis: coexistence of bronchogenic and thymic cysts in the thymus

Langerhans cell histiocytosis (LCH) is a disease caused by the proliferation of Langerhans cells in various tissues or organs. A 43-year-old male patient presented with an anterior mediastinal mass in the thymus. Histological examination after a thymectomy revealed a bronchogenic cyst in the thymus, and multiple LCH and small thymic cysts were also incidentally observed in the thymus. Unifocal LCH in an adult occurring in the thymus is extremely rare. Furthermore, no cases of LCH with the coexistence of bronchogenic and thymic cysts in the thymus have been previously reported.