Perivascular Lymphoid Aggregates Research Articles

Gemistocytic Differentiation in Isocitrate Dehydrogenase Mutant Astrocytomas: A Histopathological and Survival Analysis.

Gemistocytic differentiation is a rare histological feature seen in IDH mutant Astrocytomas. The 2021 World Health Organization (WHO) retains the diagnosis of IDH mutant Astrocytoma with its classical histology and tumors with the rare histological pattern of gemistocyticdifferentiation.Gemistocyticdifferentiation has historically been associated with a worse prognosis and shorter survival, and this prognostic difference has not been investigated in detail in our population. A population-based retrospective study included 56 patients with IDH mutant Astrocytoma with Gemistocytic differentiation and IDH mutant Astrocytoma diagnosed between 2010 and 2018 in our hospital. Demographic, histopathological, and clinical parameters were compared between the two groups. Gemistocyte percentage, perivascular lymphoid infiltrates, and Ki-67 proliferation index were also analyzed. A Kaplan-Meier analysis was done to analyze any prognostic difference in the overall survival time between the two groups. Patients with an IDH mutant Astrocytoma having gemistocyticdifferentiation had an average survival period of 2 years, while patients diagnosed with an IDH mutant Astrocytoma had an average survival time of approximately 6 years. There was a statistically significant decrease in survival time (p = 0.005) for patients with tumors with gemistocyticdifferentiation. The percentage of gemistocytes and the presence of perivascular lymphoid aggregates did not correlate with survival time (p = 0.303 and 0.602, respectively). Tumors with gemistocyticmorphology had a higher mean Ki-67 proliferation index (4.4%) than IDH mutant Astrocytoma (2.0%, p = 0.005). Our data suggest that IDH mutant Astrocytoma with Gemistocytic differentiation is an aggressive variant of IDH mutant Astrocytoma associated with a shorter survival time and an overall worse prognosis. This data might be helpful to clinicians in the future management of IDH mutant Astrocytoma with Gesmistocytic differentiation as an aggressive tumor.

A Detailed Analysis of Parameters Supporting the Engraftment and Growth of Chronic Lymphocytic Leukemia Cells in Immune-Deficient Mice.

Patient-derived xenograft models of chronic lymphocytic leukemia (CLL) can be created using highly immunodeficient animals, allowing analysis of primary tumor cells in an in vivo setting. However, unlike many other tumors, CLL B lymphocytes do not reproducibly grow in xenografts without manipulation, proliferating only when there is concomitant expansion of T cells. Here we show that in vitro pre-activation of CLL-derived T lymphocytes allows for a reliable and robust system for primary CLL cell growth within a fully autologous system that uses small numbers of cells and does not require pre-conditioning. In this system, growth of normal T and leukemic B cells follows four distinct temporal phases, each with characteristic blood and tissue findings. Phase 1 constitutes a period during which resting CLL B cells predominate, with cells aggregating at perivascular areas most often in the spleen. In Phase 2, T cells expand and provide T-cell help to promote B-cell division and expansion. Growth of CLL B and T cells persists in Phase 3, although some leukemic B cells undergo differentiation to more mature B-lineage cells (plasmablasts and plasma cells). By Phase 4, CLL B cells are for the most part lost with only T cells remaining. The required B-T cell interactions are not dependent on other human hematopoietic cells nor on murine macrophages or follicular dendritic cells, which appear to be relatively excluded from the perivascular lymphoid aggregates. Notably, the growth kinetics and degree of anatomic localization of CLL B and T cells is significantly influenced by intravenous versus intraperitoneal administration. Importantly, B cells delivered intraperitoneally either remain within the peritoneal cavity in a quiescent state, despite the presence of dividing T cells, or migrate to lymphoid tissues where they actively divide; this dichotomy mimics the human condition in that cells in primary lymphoid tissues and the blood are predominately resting, whereas those in secondary lymphoid tissues proliferate. Finally, the utility of this approach is illustrated by documenting the effects of a bispecific antibody reactive with B and T cells. Collectively, this model represents a powerful tool to evaluate CLL biology and novel therapeutics in vivo.

Kimura disease – A case report and review of the literature

Abstract Introduction Kimura disease (KD) is a benign chronic inflammatory disorder attributed to an immune mediated hypersensitivity. KD is commonly presented with unilateral subcutaneous tissue swelling in the head and neck area. The course is usually benign except for the potential cosmetic disfigurement. There is no consensus for the treatment of recurrent disease. Aim To illustrate a case of an uncommon cause of head and neck swelling. Case study A 41-year-old male presented with a recurrent painless swelling at his of right lower cheek swelling for 6-months. Head and neck examination revealed a 7 × 7 cm firm, non tender mass over the right mandibular region. Other systemic examination was unremarkable. Magnetic resonance imaging of the mass showed a well defined lesion 6 × 3 × 5 cm in size anterior to the right body of mandible. Surgical excision of the mass was done and histopathological examination of the specimen showed fibrocollagenous and fibrofatty tissue infiltrated by chronic inflammatory cells in the pattern of perivascular lymphoid aggregates. The infiltrate is composed predominantly of small lymphocytes and eosinophils. Results and discussion Here we described a rare cause of painless subcutaneous head and neck swelling that occurred in a middle-aged Asian man. KD usually presents as a painless subcutaneous soft-tissue swellings and associated with regional lymphadenopathy in the head and neck region. Diagnosis of KD is always a clinical dilemma with no specific diagnostic guideline. Though there is no consensus for the treatment of recurrent disease, the overall outcome is good as there is no association with malignancy. Conclusions KD should be considered in the differential diagnosis of a recurrent head and neck mass.

Anti–tumor necrosis factor α treatment of interferon‐α–induced murine lupus nephritis reduces the renal macrophage response but does not alter glomerular immune complex formation

To analyze the mechanism for the therapeutic effects of tumor necrosis factor α (TNFα) inhibition in a murine model of systemic lupus erythematosus. We used the (NZB × NZW)F(1) (NZB/NZW) mouse model of interferon-α-induced lupus nephritis and treated mice with TNF receptor type II (TNFRII) Ig after TNFα expression was detected in the kidneys. Autoantibodies were measured by enzyme-linked immunosorbent assay (ELISA), and autoantibody- forming cells were determined using an enzyme-linked immunospot assay. Activation of splenocytes was analyzed by flow cytometry. Kidneys were harvested and analyzed using flow cytometry, immunohistochemistry, ELISA, Western blotting, and real-time polymerase chain reaction. TNFRII Ig treatment stabilized nephritis and markedly prolonged survival. Autoantibody production and systemic immune activation were not inhibited, but the renal response to glomerular immune complex deposition was attenuated. This was associated with decreases in renal production of chemokines, renal endothelial cell activation, interstitial F4/80(high) macrophage accumulation, tubular damage, and oxidative stress. In contrast, perivascular lymphoid aggregates containing B cells, T cells, and dendritic cells accumulated unabated. Our data suggest that TNFα is a critical cytokine that amplifies the response of the nephron to immune complex deposition, but that it has less influence on the response of the systemic vasculature to inflammation.

A Unique Hybrid Renal Mononuclear Phagocyte Activation Phenotype in Murine Systemic Lupus Erythematosus Nephritis

Renal infiltration with mononuclear cells is associated with poor prognosis in systemic lupus erythematosus. A renal macrophage/dendritic cell signature is associated with the onset of nephritis in NZB/W mice, and immune-modulating therapies can reverse this signature and the associated renal damage despite ongoing immune complex deposition. In nephritic NZB/W mice, renal F4/80(hi)/CD11c(int) macrophages are located throughout the interstitium, whereas F4/80(lo)/CD11c(hi) dendritic cells accumulate in perivascular lymphoid aggregates. We show here that F4/80(hi)/CD11c(int) renal macrophages have a Gr1(lo)/Ly6C(lo)/VLA4(lo)/MHCII(hi)/CD43(lo)/CD62L(lo) phenotype different from that described for inflammatory macrophages. At nephritis onset, F4/80(hi)/CD11c(int) cells upregulate cell surface CD11b, acquire cathepsin and matrix metalloproteinase activity, and accumulate large numbers of autophagocytic vacuoles; these changes reverse after the induction of remission. Latex bead labeling of peripheral blood Gr1(lo) monocytes indicates that these are the source of F4/80(hi)/CD11c(int) macrophages. CD11c(hi)/MHCII(lo) dendritic cells are found in the kidneys only after proteinuria onset, turnover rapidly, and disappear rapidly after remission induction. Gene expression profiling of the F4/80(hi)/CD11c(int) population displays increased expression of proinflammatory, regulatory, and tissue repair/degradation-associated genes at nephritis onset that reverses with remission induction. Our findings suggest that mononuclear phagocytes with an aberrant activation profile contribute to tissue damage in lupus nephritis by mediating both local inflammation and excessive tissue remodeling.

Cracking Spaces in Hashimoto Thyroiditis Are Lymphatic and Prelymphatic Vessels

A century ago Hashimoto described the histologic hallmarks of struma lymphomatosa: (1) lymphoid follicles, (2) changes in the epithelial cells, (3) formation of connective tissue, and (4) diffuse round cell infiltration. He also showed some cracking spaces close to lymphoid follicles resembling vessels. The aim of this study was to investigate the possible lymphatic nature of these spaces and their prevalence in non-neoplastic thyroid tissue. Ten cases of Hashimoto thyroiditis (HT), 5 of Basedow-Graves disease (BG), and 5 of normal thyroid tissue (NT) were selected. Tissues were stained with hematoxylin and eosin, CD31 (Dako), and D2-40 (Dako) stains. Cracking spaces staining positive for CD31 and D2-40 stains were considered as lymphatic vessels. Site, distribution, intravascular valves and lymphocytes, perivascular lymphoid aggregates, and number and surface of lymphatic vessels were evaluated using a computer-assisted digital videocamera microscope (Nikon digital sigh, DS-2Mv). The number of lymphatic vessels increased from NT [3 (range, 2 to 13)] to BG [8 (range, 5 to 9)] to HT [12.5 (range, 10 to 16)]. A significant statistical difference was observed within the group (P=0.003): HT differed from NT (P=0.016) and BG (P=0.002). The area of lymphatic vessels increased from NT [0.01 mm (range, 0.01 to 0.12 mm2)] to BG [0.03 mm2 (range, 0.01 to 0.19 mm2)] to HT [0.03 mm (range, 0.01 to 0.6 mm2)]. A significant statistical difference was observed among the groups (P=0.001): NT differed from HT (P<0.001) and from BG (P<0.001). Lymphatic vessels showed valves, perivascular lymphoid aggregates, and intravascular lymphocytes. The cracking spaces shown by Hashimoto are mainly lymphatic vessels and represent a characteristic feature of autoimmune thyroid diseases.

Necrotic and inflammatory changes in metal-on-metal resurfacing hip arthroplasties

Background Necrosis and inflammation in peri-implant soft tissues have been described in failed second-generation metal-on-metal (MoM) resurfacing hip arthroplasties and in the pseudotumors associated with these implants. The precise frequency and significance of these tissue changes is unknown.Method We analyzed morphological and immunophenotypic changes in the periprosthetic soft tissues and femoral heads of 52 revised MoM arthroplasties (fracture in 21, pseudotumor in 13, component loosening in 9, and other causes in 9 cases).Results Substantial necrosis was observed in the periprosthetic connective tissue in 28 of the cases, including all pseudotumors, and 5 cases of component loosening. A heavy, diffuse inflammatory cell infiltrate composed mainly of HLA-DR+/CD14+/CD68+ macrophages and CD3+ T cells was seen in 45 of the cases. Perivascular lymphoid aggregates composed of CD3+ cells and CD20+ B cells were noted in 27 of the cases, but they were not seen in all cases of component loosening or pseudotumors. Plasma cells were noted in 30 cases. Macrophage granulomas were noted in 6 cases of component loosening. In the bone marrow of the femoral head, a macrophage and T cell response was seen in 31 of the cases; lymphoid aggregates were noted in 19 of the cases and discrete granulomas in 1 case.Interpretation Our findings indicate that there is a spectrum of necrotic and inflammatory changes in response to the deposition of cobalt-chrome (Co-Cr) wear particles in periprosthetic tissues. Areas of extensive coagulative necrosis and a macrophage and T lymphocyte response occur in implant failure and pseudotumors, in which there is also granuloma formation. The pathogenesis of these changes is uncertain but it may involve both a cytotoxic response and a delayed hypersensitivity (type IV) response to Co-Cr particles.

An immunohistochemical study of uveodermatologic syndrome in two Japanese Akita dogs

Ocular and cutaneous tissues from two Japanese Akita dogs with uveodermatologic syndrome (UVD) were subjected to immunohistochemical analysis. Light microscopic examination of the globes confirmed the presence of panuveitis of different severity in each case. The infiltrate was primarily granulomatous with prominent perivascular lymphoid aggregates. Melanophages were present throughout the affected areas, and there were scattered plasma cells. Immunohistochemistry using CD79a, CD3, MAC387 and MHC class II markers indicated that there were relatively few T lymphocytes and that most lymphocytes were of the B-cell lineage. The two skin biopsies examined also appeared to represent different stages of cutaneous pathology. The biopsy from one case was consistent with the reported features of skin lesions of canine UVD syndrome, including granulomatous dermatitis with extensive T-cell infiltration extending into the epidermis. In contrast, the skin lesion from the second case showed less inflammation, more pigmentary incontinence and evidence of dermal fibrosis. There was no immunoglobulin or complement deposition at any level within the cutaneous or ocular lesions. The findings of these two cases suggest that the skin lesions of these two dogs with UVD syndrome were mediated by T cells and macrophages (Th1 immunity), whereas the ocular lesions were more consistent with a B cell and macrophage response (Th2 immunity). This is, however, a preliminary investigation and these features may not be the same for all cases of UVD syndrome.

Cutaneous histiocytic lymphangitis: An unusual manifestation of rheumatoid arthritis

Two cases are presented of unusual cutaneous lesions associated with rheumatoid arthritis in underlying joints. The lesions were evanescent, erythematous and violaceous partly macular and partly indurated plaques, with a livedo-like pattern of erythema at the edge in one case. Histological changes were identical in the two cases. The major features were dilated, dermal lymphatics containing aggregates of inflammatory cells, mainly histiocytes, with adjacent perivascular lymphoid aggregates. An appropriate name for this reaction would appear to be cutaneous histiocytic lymphangitis.

IL-1 receptor antagonist protein production and gene expression in rheumatoid arthritis and osteoarthritis synovium.

IL-1 can participate in the perpetuation of arthritis through direct stimulation of synoviocytes and augmentation of matrix degradation. Hence, local production of the IL-1R antagonist protein (IRAP) might be an important negative feedback signal that regulates synovitis. We assessed synovial IRAP production in synovia from 30 individuals, by using a specific mAb and the immunoperoxidase staining method. IRAP was detected in 11 of 12 rheumatoid arthritis (RA) synovial tissues (ST) and was located primarily in the sublining, particularly in perivascular regions enriched for macrophages. Some staining was observed in the intimal lining of the synovium, although this was significantly less than in the sublining (p less than 0.05). Nine of 12 osteoarthritis (OA) tissues were positive for IRAP. In contrast to RA, the staining was observed primarily in the synovial lining in OA, with only minimal sublining IRAP being detected. Synovia from four patients without arthritis were negative (three autopsy specimens and one post-traumatic sample). Of the other two patients with miscellaneous diagnoses, one sample was negative (tenosynovitis) and one was positive (seronegative inflammatory arthritis) (sublining). Studies of serial sections and double-immunostaining experiments indicated that macrophages are the major cells containing immunoreactive IRAP. IRAP gene expression in vivo was determined by performing in situ hybridization on ST from 17 arthritis patients. RNA sense IRAP probes did not hybridize to any tissues. Anti-sense IRAP probes bound to two of nine RA tissues, two of six OA tissues, one of one seronegative inflammatory arthropathy tissue, and none of one flexor tenosynovitis tissue. As with immunoreactive protein, IRAP mRNA was primarily localized to cells in the synovial lining in OA but was more prominent in perivascular lymphoid aggregates in RA and seronegative inflammatory arthropathy. Northern blot analysis was performed on RNA isolated from nine ST. The appropriately sized IRAP band was identified in six of nine samples (five of six RA and one of three OA). Supernatants from cultured RA and OA ST cells contained immunoreactive and biologically active IRAP. Hence, IRAP gene expression and protein production occur in RA and OA synovium, albeit in different distributions.

Increased vascular permeability and leucocyte emigration in Escherichia coli endotoxin injury in the chicken skin

The permeability response was examined in chickens following intradermal injection of Escherichia coli endotoxin. The ‘dye’ and ‘colloidal carbon’ techniques were employed. The endotoxin evoked a monophasic response of immediate-prolonged type. The increase in vascular permeability was confined to venules and small veins only, indicating its mediation by endogenous permeability factors. The carbon labelling exhibited arboreal, disjointed and rectangular to hexagonal patterns. Histologically, a striking feature of the reaction was an accumulation of basophils in unusually large numbers. No other type of stimulus appears to induce basophilic response of a similar magnitude in the chicken. The results suggest that endotoxin, being a bacterial product, may exert a chemotactic effect on basophils. Hyperaemia, oedema, necrosis and formation of perivascular lymphoid aggregates were also recognised.

Attempted induction of local Shwartzman reaction in the chicken

Chickens and rabbits were injected intradermally with an endotoxin, namely Escherichia coli lipopolysaccharide (LPS). Twenty-four hours later, LPS was again administered intravenously to induce a local Shwartzman reaction. A typical cutaneous inflammatory reaction developed in rabbits, but not in chickens. Even very high doses of LPS, that made the birds visibly sick, failed to elicit the reaction. The results suggest that chickens are refractory to the Shwartzman reaction. A noteworthy feature of the chickens' response to intradermal endotoxin was the formation of prominent perivascular lymphoid aggregates.

Electron microscopic study of rheumatoid synovial vasculature. Intimate relationship between tall endothelium and lymphoid aggregation.

The relationship between (a) "tallness" and (b) cross-sectional area of the endothelial cells (EC) of postcapillary venules (PCV) and capillaries and the cellular composition of adjacent perivascular mononuclear cell infiltrates in rheumatoid (RA) synovial membrane has been examined by electron microscopy. "Tallness" of the EC was measured as the ratio of the height of the EC to its base (H/B). H/B showed a strong positive correlation with the number and percent of perivascular lymphocytes, i.e., the denser the lymphoid aggregation, the taller the EC. In contrast, H/B showed negative correlations with percent perivascular plasma cells, macrophages, and fibroblast(cyte)s. No such correlations were observed with pericapillary infiltrates. A computer-based morphometric technique yielded similar relationships between the cross-sectional area of the EC and the composition of the perivascular infiltrates. These results indicate that the EC of PCV in lymphocyte-rich areas of synovium tend to be tall and to occupy an increased fraction of the cross-sectional area of the vessel. In contrast, in areas rich in macrophages and plasma cells, EC tend to be flat and to occupy a smaller fraction of the cross-sectional area. PCV in uninfiltrated interstitial areas and in normal synovium had flat EC, and capillaries had flat EC regardless of the character of the surrounding infiltrate. Finally, PCV in lymphocyte-rich areas closely resembled those of tonsil in appearance. Our findings indicate that the PCV of the RA synovial membrane from which lymphocytes emigrate to form perivascular lymphoid aggregates resemble those of lymphoid tissue. They suggest that chronic inflammatory tissue and normal lymphoid tissue share mechanisms of lymphocyte emigration.