Expression of Angiogenic and Vasculogenic Factors in Human Lymphedematous Tissue

Association between the single-nucleotide polymorphism (rs1030868) variant in matrix metallopeptidase 2 gene and the development of lymphedema

Background

Understanding the genetic and molecular pathophysiology of lymphedema contributes to the identification of the complex interaction of genes associated with lymphedema and provides a key therapeutic opportunity to restore lymphatic function. This study aims to answer whether the single-nucleotide polymorphism (SNP) rs1030868 in the MMP-2 gene could be an associated variant in lymphedema development.

Methods

This study was carried out on 93 lymphedema cases (patients’ group) and 187 healthy individuals (control group). Genotyping of MMP-2 (rs1030868) was done following the protocol of Custom TaqMan® SNP Genotyping Assays. TaqMan™ Fast Advanced Master Mix (Cat# 4448892) was used.

Results

The risk alleles for MMP-2 SNP rs1030868 were A and G of lymphedema development. The GG genotype was associated with triple the risk of lymphedema (OR 3.2, 95% CI 1.2–6.5, p = 0.019), while the AA genotype was associated with 5.9 times the likelihood of lymphedema (OR 5.9, 95% CI 2.3–11.9, p < 0.001).

Conclusions

We concluded that the single-nucleotide polymorphisms of rs1030868 in the matrix metallopeptidase 2 gene (allele A and allele G) could be associated variants with the development of lymphedema.

Clinical Significance of Serum Collagen Type IV and Procollagen Type III N-Peptide Levels in Diagnosis and Differential Diagnosis of Lymphedema

Background: Lymphatic endothelial cells production or modification were closely related to the extracellular matrix (ECM) molecules. The serum hyaluronic acid (HA), laminin (LN), procollagen type III N-peptide (PIIINP), and collagen type IV (CGIV) levels were researched to explore the clinical significance of serum ECM proteins in the diagnosis and differentiation of lymphedema. Methods: Fifty-five patients were enrolled. They were divided into primary lymphedema (PLE), secondary lymphedema (SLE), and venous edema (VE) groups. Twenty-two healthy controls were also recruited as normal control (NC). Serum HA, LN, PIIINP, and CGIV levels of all subjects were assessed using chemiluminescence immunoassay. Statistical analysis and receiver operating characteristic (ROC) curves were used to data analysis. Results: The serum levels of CGIV were significantly decreased in both PLE and SLE groups compared with those in the NC group. Reduced serum CGIV levels were associated with the severity of lymphedema. The serum levels of CGIV and PIIINP were identified decreased in both PLE and SLE groups compared with those in the VE group. However, the levels of serum HA and LN were not observed significantly changed in both PLE and SLE groups than those in NC or VE group. Furthermore, ROC curve indicated that serum CGIV and PIIINP were capable of providing good diagnostic and differential diagnostic efficacy at the most appropriate cutoff point value. Conclusion: The serum levels of CGIV may have clinical significance in the diagnosis of lymphedema. CGIV and PIIINP may play a role in the differentiation of lymphedema from VE.

Current Understanding of Pathological Mechanisms of Lymphedema

Significance: Lymphedema is a common disease that affects hundreds of millions of people worldwide with significant financial and social burdens. Despite increasing prevalence and associated morbidities, the mainstay treatment of lymphedema is largely palliative without an effective cure due to incomplete understanding of the disease. Recent Advances: Recent studies have described key histological and pathological processes that contribute to the progression of lymphedema, including lymphatic stasis, inflammation, adipose tissue deposition, and fibrosis. This review aims to highlight cellular and molecular mechanisms involved in each of these pathological processes. Critical Issues: Despite recent advances in the understanding of the pathophysiology of lymphedema, cellular and molecular mechanisms underlying the disease remains elusive due to its complex nature. Future Directions: Additional research is needed to gain a better insight into the cellular and molecular mechanisms underlying the pathophysiology of lymphedema, which will guide the development of therapeutic strategies that target specific pathology of the disease.

Biomarkers Associated with Lymphedema and Fibrosis in Patients with Cancer of the Head and Neck

BACKGROUND

This study examined interrelationships of selected interleukins (ILs), tumor growth factors, matrix metalloproteinases (MMPs), and C-reactive protein, interferon-gamma (IFN-γ), and tumor necrosis factor α (TNF-α) with lymphedema/fibrosis in patients with head and neck cancer (HNC).

METHODS AND RESULTS

Patients newly diagnosed with ≥Stage II HNC (N = 100) were assessed for external/internal lymphedema and/or fibrosis before treatment, end-of-treatment, and at regularly established intervals through 72 weeks posttreatment and blood was drawn. Data from 83 patients were analyzed. Group-based trajectory modeling generated patient groups with similar longitudinal biomarker and lymphedema-fibrosis trajectories. Area-under-the-curve (AUC) values were also generated for each biomarker and severity of lymphedema-fibrosis. Associations among and between biomarkers and lymphedema-fibrosis trajectories and AUCs were tested (log-likelihood chi-square, correlations). The strongest evidence for the association of biomarkers with the overall and trajectory patterns and severity of lymphedema-fibrosis was observed for IL-6, IL-1β, TNF-α, TGF-β1, and MMP-9 (all p < 0.05). Convergence of joint trajectory patterns and AUC were observed with IL-6 with all lymphedema-fibrosis trajectories and internal lymphedema AUC. IL-1β trajectories converged with external lymphedema trajectories and all lymphedema-fibrosis AUCs. TNF-α and TGF-β1 converged most strongly with fibrosis in terms of trajectory patterns. However TNF-α demonstrated stronger association with lymphedema-fibrosis AUC (fibrosis: rs = 0.49). MMP-9 demonstrated convergence with lymphedema-fibrosis AUCs (lymphedema: 0.43-0.42; fibrosis: 0.35).

CONCLUSION

Systemic levels of selected mediators of proinflammatory processes track with acute and chronic clinical phenotypes of lymphedema/fibrosis in HNC patients suggesting their potential role in the pathogenesis of these conditions.

Single nucleotide polymorphisms in the angiogenic and lymphangiogenic pathways are associated with lymphedema caused by Wuchereria bancrofti

Background

Lymphedema (LE) is a chronic clinical manifestation of filarial nematode infections characterized by lymphatic dysfunction and subsequent accumulation of protein-rich fluid in the interstitial space—lymphatic filariasis. A number of studies have identified single nucleotide polymorphisms (SNPs) associated with primary and secondary LE. To assess SNPs associated with LE caused by lymphatic filariasis, a cross-sectional study of unrelated Ghanaian volunteers was designed to genotype SNPs in 285 LE patients as cases and 682 infected patients without pathology as controls. One hundred thirty-one SNPs in 64 genes were genotyped. The genes were selected based on their roles in inflammatory processes, angiogenesis/lymphangiogenesis, and cell differentiation during tumorigenesis.

Results

Genetic associations with nominal significance were identified for five SNPs in three genes: vascular endothelial growth factor receptor-3 (VEGFR-3) rs75614493, two SNPs in matrix metalloprotease-2 (MMP-2) rs1030868 and rs2241145, and two SNPs in carcinoembryonic antigen-related cell adhesion molecule-1 (CEACAM-1) rs8110904 and rs8111171. Pathway analysis revealed an interplay of genes in the angiogenic/lymphangiogenic pathways. Plasma levels of both MMP-2 and CEACAM-1 were significantly higher in LE cases compared to controls. Functional characterization of the associated SNPs identified genotype GG of CEACAM-1 as the variant influencing the expression of plasma concentration, a novel finding observed in this study.

Conclusion

The SNP associations found in the MMP-2, CEACAM-1, and VEGFR-3 genes indicate that angiogenic/lymphangiogenic pathways are important in LE clinical development.

Electronic supplementary material

The online version of this article (10.1186/s40246-017-0121-7) contains supplementary material, which is available to authorized users.

VEGF-C improves regeneration and lymphatic reconnection of transplanted autologous lymph node fragments: An animal model for secondary lymphedema treatment

Secondary lymphedema occurs after for example breast cancer surgery and radiation in 20–50% of the patients. Due to the poor outcomes of surgical treatments in the past, the therapy often remains symptomatic. However, avascular transplantation of autologous lymph node fragments (LN-Tx) combined with postoperative injections of vascular endothelial growth factor-C (VEGF-C) emerges as a potential surgical therapy. In this study, adult rats underwent LN-Tx to investigate the following parameters of VEGF-C application: time point, location and dosage. Furthermore, the influences of VEGF-C on lymphatic reconnection and transplant regeneration were analyzed. The reconnection was investigated using intradermally injected blue dye and the regeneration was evaluated histologically using hematoxylin-eosin (H&E) staining and immunohistochemistry. The higher dosage enhanced the reconnection rates significantly and showed a statistical tendency of improving regeneration. An application on early postoperative days and the injection into the medial thigh improved the reconnection significantly. However, these variables did not affect the regeneration statistically. This study confirms that LN-Tx combined with lymphatic growth factor VEGF-C is a possible approach in the therapy of secondary lymphedema and shows the important role of VEGF-C application parameters.

Male genital lymphedema: clinical features and management in 25 pediatric patients

PURPOSE

Genital lymphedema in the pediatric population is poorly understood. The purpose of this study was to determine the epidemiology, morbidity, and treatment outcomes for males with genital lymphedema.

MATERIALS AND METHODS

Male patients with genital lymphedema evaluated at our vascular anomalies center between 1995 and 2011 were reviewed. Etiology, age-of-onset, location, morbidity, and treatment were analyzed.

RESULTS

Of the 3889 patients with vascular anomalies, 25 (0.6%) had genital lymphedema: 92% (23/25) with primary and 24.0% (6/25) with familial/syndromic lymphedema. For primary disease, the mean age-of-onset was 4.5 ± 6.3 years with 60.9% (14/23) presenting in infancy, 13.0% (3/23) in childhood, and 26.1% (6/23) in adolescence. Combined penoscrotal lymphedema was identified in 72.0% (18/25) of patients; 19 children (76.0%) had concomitant lower extremity involvement. The most common complication was cellulitis (24.0%). Surgical contouring was performed in 44.0% (11/25) of patients. Patients with operative intervention and follow-up (n=6) had sustained improvement after a median of 4.2 years (range: 0.3-11.0).

CONCLUSIONS

Lymphedema of the male genitalia is typically idiopathic. Most patients develop swelling in infancy but can present in adolescence and occasionally childhood. The penis and scrotum are usually both involved and concurrent lower-extremity swelling is common. Surgical debulking can improve symptoms and appearance.