Cerebral Microvascular Erdheim-Chester Disease: A Perivascular Hematopoietic Vasculopathy

Erdheim-Chester disease (ECD) is a rare and elusive hematopoietic malignancy that may involve the nervous system in various ways. Cerebrovascular ECD involves the perivascular infiltration and compromise of any cervicocranial vessel by transformed proliferating histiocytes. Presented is the novel case of a patient with pathologically proven perivascular microangiopathy, manifesting in multifaceted fashion with ischemia, hemorrhage, mass lesions, and edema.

Inflammatory Cell Infiltration of Adrenals in COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was originated in November–December 2019 in Wuhan, China, and has rapidly spread around the world causing severe health and socioeconomical damage to the entire civilization. The key feature of coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2, is upper respiratory tract infection, which may be complicated by bilateral pneumonia. Angiotensin converting enzyme 2 (ACE2) has been identified as a key host factor, required for virus entry into cells. Interestingly, ACE2 is expressed not only in the respiratory system, but also in the other organs and systems including adrenal glands. Here we provide the first description of the pathomorphological changes in adrenal glands in patients with severe COVID-19 characterized by perivascular infiltration of CD3+ and CD8+ T-lymphocytes. Due to the central role of the adrenals in the stress response of the organism, this finding is of potential clinical relevance, because infection with the SARS-CoV-2 virus might critically impair adrenal function under pathophysiological conditions.

A Simple and Effective Flow Cytometry-Based Method for Identification and Quantification of Tissue Infiltrated Leukocyte Subpopulations in a Mouse Model of Peripheral Arterial Disease

Arteriogenesis, the growth of a natural bypass from pre-existing arteriolar collaterals, is an endogenous mechanism to compensate for the loss of an artery. Mechanistically, this process relies on a locally and temporally restricted perivascular infiltration of leukocyte subpopulations, which mediate arteriogenesis by supplying growth factors and cytokines. Currently, the state-of-the-art method to identify and quantify these leukocyte subpopulations in mouse models is immunohistology. However, this is a time consuming procedure. Here, we aimed to develop an optimized protocol to identify and quantify leukocyte subpopulations by means of flow cytometry in adductor muscles containing growing collateral arteries. For that purpose, adductor muscles of murine hindlimbs were isolated at day one and three after induction of arteriogenesis, enzymatically digested, and infiltrated leukocyte subpopulations were identified and quantified by flow cytometry, as exemplary shown for neutrophils and macrophages (defined as CD45+/CD11b+/Ly6G+ and CD45+/CD11b+/F4/80+ cells, respectively). In summary, we show that flow cytometry is a suitable method to identify and quantify leukocyte subpopulations in muscle tissue, and provide a detailed protocol. Flow cytometry constitutes a timesaving tool compared to histology, which might be used in addition for precise localization of leukocytes in tissue samples.

Perivascular Tumor-Infiltrating Leukocyte Scoring for Prognosis of Resected Hepatocellular Carcinoma Patients

Liver resection is a curative treatment for hepatocellular carcinoma (HCC). Tumor-infiltrating leukocytes (TILs) are important players in predicting HCC recurrence. However, the invasive margin could not be confirmed as relevant for HCC. The migration of immune cells into HCC may originate from intratumoral vessels. No previous study has examined perivascular (PV) infiltration. Tumors from 60 patients were examined. Immunohistochemistry was performed against CD3, CD8, CD20, and CD66b. TILs were counted in the PV regions using an algorithm for quantification of the tumor immune stroma (QTiS). The results were correlated with overall (OS) and disease-free survival (DFS), clinical parameters, and laboratory values. PV infiltration of TILs was predominant in resected HCC. Higher PV infiltration of CD3+ (p = 0.016) and CD8+ (p = 0.028) independently predicted better OS and DFS, respectively. CD20+ showed a trend towards better DFS (p = 0.076). Scoring of CD3+, CD8+, and CD20+ independently predicted OS and DFS (p < 0.01). The amount of perivascular-infiltrating CD3+ cells is an independent predictor of better OS, and CD8+ cells independently predict prolonged DFS. Our novel perivascular infiltration scoring (PVIS) can independently predict both DFS and OS in resected HCC patients.

Endothelin 1, NF-κB, and ADAM-15 Expression in Diabetic Foot Wounds

The diabetic foot is an important and destructive complication of diabetes. This study examined 65 individuals (35 males, 30 females) diagnosed with diabetic foot and having open wounds on their feet. Blood parameters differed significantly between diabetic and non-diabetic patients. After washing the foot with isotonic solution, the wound was debrided and the excised tissues (diabetic dermis) were fixed with neutral buffered 10% formalin solution. Specimens stained with haematoxylin-eosin, endothelin-1 (ET-1), nuclear factor kappa B (NF-&kappa;B), and ADAM 15 antibodies were used to examine angiogenesis, cytokine activity, and the extracellular matrix, respectively. Histopathologically, in the diabetic feet of males, leukocytes, lymphocytes, and macrophages were spread diffusely throughout the lesion, with inflammatory cells invading all layers of blood vessels. In the diabetic feet of females, dilation and congestion of the blood vessels, degenerative changes in the subendothelial layer, and perivascular infiltration by lymphocytes were observed. ET-1 was expressed in inflammatory cells around pre-capillary vessels in the stromal area. NF-&kappa;B was expressed in macrophages around blood vessels, and in nodular organised cells distributed throughout the perivascular space. ADAM 15 was expressed in fibroblasts, endothelial cells, and inflammatory cells. ET-1 expression in the endothelial cells of diabetic foot ulcers is an important determinant of insulin resistance at the onset of disease and induces macrophages to produce NF-&kappa;B, which regulates inflammation. It is thought that ADAM 15 contributes to angiogenic effects as a means of stimulating endothelial cells.

Morphological Diversity of Pretibial Myxedema and Its Mechanism of Evolving Process and Outcome: A Retrospective Study of 216 Cases

Background. Pretibial myxedema (PTM) is a rare dermopathy. The morphologic features and mechanism of its evolving process are not reported in large case series.Methods. 216 cases with PTM were retrospectively reviewed to analyze demographics, history, lesional morphology and its evolving process, histopathology and immunohistochemistry, serum TRAb levels, treatment, and outcome.Results. First appearing lesions evolved into 6 variants that were correlated with serum TRAb levels. Subvariants were caused by different kinds and frequencies of local trauma. The evolving process could be classified into 4 stages that were correlated with serum TRAb levels and perivascular infiltration of CD8+ and CD4+ lymphocytes. Serum TRAb levels at remission and in nonrecurred cases became lower than those before therapy and in recurred cases, respectively, but increased when PTM relapsed. TRAb level in nodule variant went down invariably with the extension of course and its autoimmune activity had a trend to stop but in other 5 variants TRAb levels fluctuated. Their autoimmune activities had no trends to stop and clinically worsen through intermittent repeats of active and stable stages.Conclusions. In the chronic course of PTM, nodule variant is self-limited and other 5 variants are not self-limited. PTM needed early treatment to avoid severe variants.

Evaluation of Histopathological Changes in Control Biopsies Which Taken 48 Sessions after NBUVB Phototherapy for Early-Stage Mycosis Fungoides

Background.There are not many studies investigating histomorphological changes in 48 sessions in patients with early-stage MF after narrowband UVB (NBUVB) treatment. Our purpose is to evaluate histological features of phototherapy after 48 sessions and determine which parameters are more reliable for controlling skin biopsies.Methods.Biopsies of 32 patients with early stage of MF, who were treated with NBUVB phototherapy, were histologically evaluated before and after the treatments, including epidermotropism, stratum corneum, epidermal thickness, dermal infiltration, papillary dermal fibrosis, vascular alterations, and other dermal changes. We discuss the histomorphological effects of NBUVB phototherapy on skin biopsies by comparing the responders with nonresponders, with before and after the treatment.Results.9 patients (28%) did not give any response to treatment. Alleviation in epidermotropism, increases in parakeratosis and normal keratosis, perivascular infiltration, and melanophages, decrease in the lichenoid/patchy lichenoid infiltration pattern after the treatment was statistically significant. Comparing by response, normalization of stratum corneum and epidermis, orthohyperkeratosis, decrease in linearly arranged cells, the lichenoid/patchy lichenoid infiltration, the loss of inflammation were statistically significant in responders group.Conclusion.We detected a significant decrease in linearly arranged cells after phototherapy, indicating that it is an “important diagnostic parameter" in evaluation of therapeutic response.