Immunohistochemical Analysis of Endothelial Cells in Vascular Transformation of Lymph Node Sinuses: Vascular or Lymphatic Differentiation?

Prevalence and risk factors of lymphatic dysfunction in cirrhosis patients with refractory ascites: An often unconsidered mechanism

BACKGROUND

The lymphatic system is crucial in maintaining the body fluid homeostasis. A dysfunctional lymphatic system may contribute to the refractoriness of ascites and edema in cirrhosis patients. Therefore, assessment of lymphatic dysfunction in cirrhosis patients with refractory ascites (RA) can be crucial as it would call for using different strategies for fluid mobilization.

AIM

To assessing the magnitude, spectrum, and clinical associations of lymphatic dysfunction in liver cirrhosis patients with RA.

METHODS

This observational study included 155 consecutive cirrhosis patients with RA. The presence of clinical signs of lymphedema, such as peau d'orange appearance and positive Stemmer sign, intestinal lymphangiectasia (IL) on duodenal biopsy seen as dilated vessels in the lamina propria with strong D2-40 immunohistochemistry, and chylous ascites were used to diagnose the overt lymphatic dysfunctions.

RESULTS

A total of 69 (44.5%) patients out of 155 had evidence of lymphatic dysfunction. Peripheral lymphedema, found in 52 (33.5%) patients, was the most common manifestation, followed by IL in 42 (27.0%) patients, and chylous ascites in 2 (1.9%) patients. Compared to patients without lymphedema, those with lymphedema had higher mean age, median model for end-stage liver disease scores, mean body mass index, mean ascitic fluid triglyceride levels, and proportion of patients with hypoproteinemia (serum total protein < 5 g/dL) and lymphocytopenia (< 15% of total leukocyte count). Patients with IL also had a higher prevalence of lymphocytopenia and hypoproteinemia (28.6% vs. 9.1%, P = 0.004). Seven (13%) patients with lymphedema had lower limb cellulitis compared to none in those without it. On multivariate regression analysis, factors independently associated with lymphatic dysfunction included obesity [odds ratio (OR): 4.2, 95% confidence intervals (95%CI): 1.1-15.2, P = 0.027], lymphocytopenia [OR: 6.2, 95%CI: 2.9-13.2, P < 0.001], and hypoproteinemia [OR: 3.7, 95%CI: 1.5-8.82, P = 0.003].

CONCLUSION

Lymphatic dysfunction is common in cirrhosis patients with RA. Significant indicators of its presence include hypoproteinemia and lymphocytopenia, which are likely due to the loss of lymphatic fluid from the circulation. Future efforts to mobilize fluid in these patients should focus on methods to improve lymphatic drainage.

Cutaneous vascular structure and perfusion in patients with chronic plaque psoriasis

BACKGROUND

Vascular dysfunction is a significant contributor to the pathophysiology of psoriasis. Some individuals have variation within the gene for vascular endothelial growth factor-A (VEGF-A), which confers an increased risk of developing psoriasis and having a severe disease phenotype, and may determine responsiveness to treatment.

AIM

To determine whether patients with psoriasis have alterations in cutaneous microvascular anatomy and physiology due to expression of VEGF and whether laser Doppler imaging has utility in the assessment of this.

METHODS

Twelve adult volunteers with Type 1 chronic plaque psoriasis underwent laser Doppler imaging of plaque and uninvolved skin. Skin biopsies were taken from the areas imaged for immunohistochemistry, including blood and lymphatic vessel markers, and VEGF-A isotype analysis (VEGF-A121, VEGF-A165 and VEGF-D). Venous blood was collected for DNA extraction, VEGF-A genotyping and peripheral blood mononuclear cell culture.

RESULTS

Mean blood vessel area (P < 0·01), number of blood vessels (P < 0·001), number of lymphatic vessels (P < 0·001) and blood flow (P < 0·001) was significantly increased in psoriasis plaques, as was expression of VEGF-A121 (P < 0·01), VEGF-A165 (P < 0·04) and VEGF-D (P < 0·01). Blood flow within psoriasis plaques was independent of their increased vascularity (P < 0·01) and may be associated with baseline productivity of VEGF. The number of blood vessels within uninvolved skin in patients with psoriasis was associated with the VEGF-A (rs833061) genotype (P = 0·01), in a relationship suggesting an allele dosing effect.

CONCLUSION

Noninvasive imaging of blood flow may help determine the cutaneous vascular signature for individual patients. This may be a useful prognostic indicator of psoriasis susceptibility and severity, and thus support selection of treatments.

Nodular Vascular Transformation of the Lymph Node Sinuses Mimicking Sarcomatoid Change in Renal Cell Carcinoma: A Potential Diagnostic Pitfall

Vascular transformation of the lymph node sinuses (VTS) is an uncommon phenomenon that is believed to occur secondary to obstruction of efferent lymphatics, frequently occuring in retroperitoneal lymph nodes draining cancer. The nodular subtype of VTS, in particular, can mimic metastatic cancer, such as metastatic renal cell carcinoma with sarcomatoid differentiation, potentially resulting in inaccurate tumor grading and/or staging. We present a case of nodular VTS mimicking metastatic renal cell carcinoma with sarcomatoid differentiation in a patient with high-grade clear cell renal cell carcinoma, and explore the relevant differential diagnosis. Awareness of VTS is essential to avoid misdiagnosis of this benign and curative condition.

Effects of mobilized peripheral blood stem cells on treatment of primary lower extremity lymphedema

OBJECTIVE

Lymphedema is a chronic debilitating disease characterized by the accumulation of fluid in the extremities as a result of lymphatic system impairment. Current treatments fail to restore the functionality and structural integrity of the lymphatic vessels lost in this condition. In this study, autologous mobilized peripheral blood stem cell transplantation was used and its potential efficacy and safety were evaluated in treating this condition.

METHODS

Ten patients with primary lymphedema in the lower extremity received granulocyte-colony stimulating factor subcutaneously for 4 days, to stimulate stem cell mobilization, after which 200 to 250 mL of blood was drawn from each patient and used to collect stem cells. Mobilized stem cells were counted by flow cytometry with International Society of Hematotherapy and Graft Engineering method. In two sessions, 3 weeks apart, these stem cells were injected subcutaneously in the affected limb at approximately 80 points, along the lymphatic vessels. Each patient was followed for 6 months, during which changes in the limb volume and circumference were measured. Lymphangiogenesis was evaluated by biopsy, the lymphoscintigraphic transport index was calculated using Lymphoscintigraphy, and quality of life was surveyed.

RESULTS

In this study, patients received on average 9.5 ± 6.8 × 10⁸ mononuclear cells (which divided into 2 × 10⁶ CD34⁺ cells for each session) in two sessions. The volume of the lower limbs decreased in 60% of patients. One patient showed a slight increase in the volume of lower limbs and three showed no change. The average limb volume was 4469.41 ± 1760.71 cm³, which on average differed from the average initial limb volume by 232.88 ± 392.53 cm³. Quality of life was reported as slightly increased in 60% of patients. The lymphoscintigraphic transport index suggested improvement in 60% of the patients. Likewise, tissue samples showed a 60% increase in lymphatic vessels.

CONCLUSIONS

Subcutaneous injection of autologous hematopoietic stem cells harvested from peripheral blood into patients with primary lower limb lymphedema is feasible, potentially effective, and without serious adverse effects. However, a larger scale study with more patients is needed to validate our results. Last, to increase the effectiveness of this treatment, the optimal dose of cells injected and the requirement for additional growth factors need further study.

Intussusceptive lymphangiogenesis in vascular transformation of lymph node sinuses

Numerous lymphatic anastomosing channels in the lymph nodes are the most demonstrative finding of the rare lesion termed "vascular transformation of lymph node sinuses" (VTS). The mechanism of lymphatic vessel formation in VTS has not been studied. Vessel intussusception contributes to vascular expansion, and intraluminal pillars/posts, interstitial tissue structures or larger pillars (ITSs) and folds are the hallmarks of this process in blood vessels. The aim of this work is to assess whether these hallmarks of intussusception occur in VTS lymphatic vessels, indicating intussusceptive lymphangiogenesis. For this purpose, specimens of five cases of VTS were used for serial histological sections, immunohistochemistry and immunofluorescence in confocal microscopy, which enabled us to demonstrate the 3D image that defines the pillars. The studies showed a) meshworks of lymphatic vessels, which form complex loops, resembling sinuses of lymph nodes, b) presence of intralymphatic pillars, ITSs and folds, with a cover of lymphatic endothelial cells expressing podoplanin and a varying-sized connective core (e.g. collagen), and c) increase of vessel meshwork and linear arrangement, splitting and fusion of ITSs, pillars and folds, with remodelling and segmentation. In conclusion, the development of lymphatic vessel loops, ITSs, pillars and folds with segmentation in VTS supports intussusceptive lymphangiogenesis. This mechanism of intussusception is of interest because it participates in VTS histogenesis, contributes to general knowledge of intussusceptive lymphangiogenesis, which has received less attention than intussusception in blood vessels, and provides a basis for further studies in other lymphatic conditions.