Progress towards eliminating lymphatic filariasis in Zanzibar: a model programme

Programmes to eliminate lymphatic filariasis are underway in ten countries of sub-Saharan Africa, and in several programmes outside Africa five rounds of mass drug administration (MDA) are being completed. In Africa, Egypt and Zanzibar have completed five rounds of MDA. Zanzibar was the first country to complete five rounds of treatment using a combination of albendazole and ivermectin, reducing both the prevalence and intensity of Wuchereria bancrofti. Characteristics of the Zanzibar programme serve as a model for other countries: factors crucial to its success include high-level political commitment, the development of appropriate social mobilization strategies, the involvement of communities in drug distribution, and the introduction of morbidity management for individuals with lymphoedema.     

Impact on the quality of life of lymphoedema patients following introduction of a hygiene and skin care regimen in a Guyanese community endemic for lymphatic filariasis: A preliminary clinical intervention study

BACKGROUND: Hygiene and skin care are effective and important interventions in the management of lymphoedema secondary to lymphatic filariasis. We analyzed the impact on the quality of life that education and introduction of a designated nurse had on lymphoedema patients in a community that was endemic for lymphatic filariasis. METHODS: Patients' life quality was assessed using a Dermatology Life Quality Index (DLQI) questionnaire. At the same time they received education on appropriate hygiene, skin care techniques and simple exercises that encourage lymph drainage. A designated nurse was provided with educational materials and treatments. The DLQI life quality measure was repeated one year later. RESULTS: The DLQI improved for all patients and reported acute attacks were reduced. A paired t-test showed the improvement in DLQI to be highly significant (P = < 0.0001). CONCLUSIONS: A nurse-led service combined with patient education in communities endemic for lymphatic filariasis is an effective intervention in improving the quality of life of patients with lymphoedema.     

Some observations on the effect of Daflon (micronized purified flavonoid fraction of Rutaceae aurantiae) in bancroftian filarial lymphoedema

BACKGROUND: Morbidity management is a core component of the global programme for the elimination of lymphatic filariasis. In a double-blind clinical trial, the tolerability and efficacy of Daflon (500 mg) + DEC (25 mg) or DEC (25 mg) alone, twice daily for 90 days, was studied in 26 patients with bancroftian filarial lymphoedema. RESULTS: None of the patients in either drug group reported any adverse reaction throughout the treatment period (90 days). Haematological and biochemical parameters were within normal limits and there was no significant difference between the pre-treatment (day 0) and post-treatment (day 90) values. The group receiving Daflon showed significant reduction in oedema volume from day 90 (140.6 PlusMinus; 18.8 ml) to day 360 (71.8 PlusMinus; 20.7 ml) compared to the pre-treatment (day 0, 198.4 PlusMinus; 16.5 ml) value. This accounted for a 63.8% reduction in oedema volume by day 360 (considering the pre-treatment (day 0) as 100%). In the DEC group, the changes in oedema volume (between day 1 and day 360) were not significant when compared to the pre-treatment (day 0) value. The percentage reduction at day 360 was only 9%, which was not significant (P > 0.05). CONCLUSION: This study has shown that Daflon (500 mg, twice a day for 90 days) is both safe and efficacious in reducing oedema volume in bancroftian filarial lymphoedema. Further clinical trials are essential for strengthening the evidence base on the role of this drug in the morbidity management of lymphatic filariasis.     

Morbidity management in the Global Programme to Eliminate Lymphatic Filariasis: a review of the scientific literature

The Global Programme to Eliminate Lymphatic Filariasis (GPELF) has two major goals: to interrupt transmission of the parasite and to provide care for those who suffer the devastating clinical manifestations of the disease (morbidity control). This latter goal addresses three filariasis-related conditions: acute inflammatory episodes; lymphoedema; and hydrocele. Research during the last decade has confirmed the importance of bacteria as a cause of acute inflammatory episodes in filariasis-endemic areas, known as acute dermatolymphangioadenitis (ADLA). Current lymphoedema management strategies are based on the central role of ADLA as a trigger for lymphoedema progression. Simple intervention packages are in use that have resulted in dramatic reductions in ADLA rates, a lower prevalence of chronic inflammatory cells in the dermis and subdermis, and improvement in quality of life. During the past decade, the socioeconomic impact of ADLA and lymphoedema in filariasis-endemic areas has received increasing attention. Numerous operational research questions remain to be answered regarding how best to optimize, scale up, monitor, and evaluate lymphoedema management programmes. Of the clinical manifestations targeted by the GPELF, hydrocele has been the focus of the least attention. Basic information is lacking on the effectiveness and complications of hydrocele surgery and risk of post-operative hydrocele recurrence in filariasis-endemic areas. Data on the impact of mass administration of antifilarial drugs on filarial morbidity are inconsistent. Several studies report reductions in acute inflammatory episodes, lymphoedema, and/or hydrocele following mass drug administration, but other studies report no such association. Assessing the public health impact of mass treatment with antifilarial drugs is important for programme advocacy and morbidity control strategies. Thus, although our knowledge of filariasis-related morbidity and its treatment has expanded in recent years, much work remains to be done to address the needs of more than 40 million persons who suffer worldwide from these conditions.     

The Elimination of Lymphatic Filariasis: A Strategy for Poverty Alleviation and Sustainable Development – Perspectives from the Philippines

BACKGROUND: Hygiene and skin care are effective and important interventions in the management of lymphoedema secondary to lymphatic filariasis. We analyzed the impact on the quality of life that education and introduction of a designated nurse had on lymphoedema patients in a community that was endemic for lymphatic filariasis. METHODS: Patients' life quality was assessed using a Dermatology Life Quality Index (DLQI) questionnaire. At the same time they received education on appropriate hygiene, skin care techniques and simple exercises that encourage lymph drainage. A designated nurse was provided with educational materials and treatments. The DLQI life quality measure was repeated one year later. RESULTS: The DLQI improved for all patients and reported acute attacks were reduced. A paired t-test showed the improvement in DLQI to be highly significant (P = < 0.0001). CONCLUSIONS: A nurse-led service combined with patient education in communities endemic for lymphatic filariasis is an effective intervention in improving the quality of life of patients with lymphoedema.     

Onchocerca parasites and Wolbachia endosymbionts: evaluation of a spectrum of antibiotic types for activity against Onchocerca gutturosa in vitro

Background

In the Dominican Republic, a Latin American country with filariasis-endemic areas, more than 63,000 people have lymphatic filariasis and more than 400,000 people are at risk of future infection. In this paper, we explore the health beliefs, health-seeking behaviors and self-care practices of women with lymphoedema in filariasis-endemic areas to better understand the needs of women when developing lymphoedema morbidity control programs.

Methods

Qualitative data were collected through semi-structured interviews of 28 women, 3 focus group discussions with 28 women, field notes and photographs.

Results

Women described exhaustive and expensive attempts at seeking a cure for their lymphoedema. Family members were influential in providing women with initial care seeking referrals to indigenous healers credited with influence over physical, mental, spiritual and supernatural properties of illness. When indigenous treatments proved to be ineffectual, the women sought care from trained healthcare providers. Most healthcare providers incorrectly diagnosed the edema, failed to adequately treat and meet the needs of women and were viewed as expensive. Most women resorted to self-prescribing injectable, oral, or topical antibiotics along with oral analgesics as a standard practice of self-care.

Conclusion

Healthcare providers must understand a woman's cultural perspectives of illness, her natural networks of support and referral, her behavioural practices of care-seeking and self-care and the financial burden of seeking care. In the culture of the Dominican Republic family members and traditional healthcare providers are influential advisors on initial health-seeking behaviors and self-care practices. For this reason family-oriented interventions, support groups for women and their families, community education and training on simple, low cost lymphoedema management techniques for indigenous healers are viable ways to influence the early detection, diagnosis and treatment of women with lymphoedema. The extensive use of injectable, oral and topical antibiotics by indigenous healers and women without medical supervision suggests a need for health education messages related to the risks of such practices.     

Lymphoedema management knowledge and practices among patients attending filariasis morbidity control clinics in Gampaha District, Sri Lanka

BACKGROUND: Little information is available on methods of treatment practiced by patients affected by filarial lymphoedema in Sri Lanka. The frequency and duration of acute dematolymphangioadenitis (ADLA) attacks in these patients remain unclear. This study reports the knowledge, practices and perceptions regarding lymphoedema management and the burden of ADLA attacks among patients with lymphoedema. METHODS: A semi-structured questionnaire was used to assess morbidity alleviation knowledge, practices and perceptions. The burden of ADLA attacks was assessed using one-year recall data. RESULTS: 66 patients (22 males, 44 females) with mean age 51.18 years (SD +/- 13.9) were studied. Approximately two thirds of the patients were aware of the importance of skin and nail hygiene, limb elevation and use of footwear. Washing was practiced on a daily and twice daily basis by 40.9% and 48.5% respectively. However, limb elevation, exercise and use of footwear were practiced only by 21-42.4% (while seated and lying down), 6% and 34.8% respectively. The majority of patients considered regular intake of diethylcarbamazine citrate (DEC) important. Approximately two thirds (65.2%) had received health education from filariasis clinics. Among patients who sought private care (n = 48) the average cost of treatment for an ADLA attack was Rs. 737.91. Only 18.2% had feelings of isolation and reported community reactions ranging from sympathy to fear and ridicule. CONCLUSIONS: Filariasis morbidity control clinics play an essential role in the dissemination of morbidity control knowledge. Referral of lymphoedema patients to morbidity control clinics is recommended.     

Development of an integrated,holistic care package for people with lymphoedema for use at the level of the Primary Health Care Unit in Ethiopia

BackgroundNeglected Tropical Diseases (NTDs) are a group of several communicable and non-communicable diseases prevalent in tropical and subtropical areas. The co-endemicity of these diseases, the similarity of their clinical signs, and the need to maximize limited financial and human resources suggest the importance of adoptingan integratedapproach to their prevention and treatment.AimsThis study describes the development of a comprehensive package of physical, mental health and psychosocial care for people with lower-limb lymphoedema caused bypodoconiosis, lymphatic filariasis (LF)or leprosy as part of the EnDPoINT program in Ethiopia.MethodThe care package was developed using a mixed-methods approach, consisting of a literature review, situational analysis, Theory of Change (ToC) workshops, qualitative research, and additional workshops to fine-tune the draft care package. The care package was developed between March 2018 and January 2020 in Addis Ababa and the implementation research site, Awi zone in the North-West of Ethiopia.ResultsThe holistic care package includes components implemented at three levels of the health care system:health organization, facility, and community. Sections of the care package are directed at strengthening capacity building, program management, community engagement, awareness-raising, stigma-reduction, morbidity management, disability prevention, follow-up visits, referral linkage, community-based rehabilitation, and monitoring and evaluation.ConclusionsThe study developed a holistic integrated care package for lower limb disorder and co-morbid mental health problems caused by podoconiosis, LF or leprosy. The approach has the potential to significantly reduce lower limb disorder-associated morbidity, disability, and psychosocial problems. It also standardizes a scalable approach appropriate for the Ethiopian setting and, most likely, other countries where these NTDs are present.     

Linkage and sequence analysis indicate that CCBE1 is mutated in recessively inherited generalised lymphatic dysplasia

Generalised lymphatic dysplasia (GLD) is characterised by extensive peripheral lymphoedema with visceral involvement. In some cases, it presents in utero with hydrops fetalis. Autosomal dominant and recessive inheritance has been reported. A large, non-consanguineous family with three affected siblings with generalised lymphatic dysplasia is presented. One child died aged 5 months, one spontaneously miscarried at 17 weeks gestation, and the third has survived with extensive lymphoedema. All three presented with hydrops fetalis. There are seven other siblings who are clinically unaffected. Linkage analysis produced two loci on chromosome 18, covering 22 Mb and containing 150 genes, one of which is CCBE1. A homozygous cysteine to serine change in CCBE1 has been identified in the proband, in a residue that is conserved across species. High density SNP analysis revealed homozygosity (a region of 900 kb) around the locus for CCBE1 in all three affected cases. This indicates a likely ancestral mutation that is common to both parents; an example of a homozygous mutation representing Identity by Descent (IBD) in this pedigree. Recent studies in zebrafish have shown this gene to be required for lymphangiogenesis and venous sprouting and are therefore supportive of our findings. In view of the conserved nature of the cysteine, the nature of the amino acid change, the occurrence of a homozygous region around the locus, the segregation within the family, and the evidence from zebrafish, we propose that this mutation is causative for the generalised lymphatic dysplasia in this family, and may be of relevance in cases of non-immune hydrops fetalis.     

Impact of two follow-up schemes on morbidity management and disability prevention (MMDP) programme for filarial lymphedema in Matara,Sri Lanka

Alleviating morbidity due to lymphatic filariasis (LF)—especially in elderly patients who are rather ignorant—is presently the biggest challenge for the national filariasis campaign. We introduced two follow-up schemes and compared each other to address three key programmatic issues (1) locating patients, (2) educating patients, family members on practice of lymphoedema self-care (3) well sustained daily self-care. Hundred and seven lymphoedema patients were introduced to the new Community Home Based Care (CHBC) programme as a part of MMDP programme at their homes. Twenty seven of 107 patients were selected by purposive sampling and followed-up under two schemes, 14 in Daily follow-up (DFU) scheme and 13 in Monthly follow-up (MFU) scheme. Impact was assessed using a KAP score, number of entry lesions (EL) and number of ADL episodes, limb volume, its appearance, changes in the quality of life and gained benefits. Visiting patients in their homes to introduce lymphoedema care programme was a success. KAP scores of the more important activities on lymphoedema care were significantly higher in DFU scheme. Number of patients (51.9%; 14/27) who had EL/s at baseline reduced significantly to 18.5% (5/27) at one year follow-up. The mean numbers of ADL episodes/year reduced significantly in both schemes. Six photographs of 27 showed obvious improvement in lymphoedema and its grade. Mean volume of lymphoedema reduced significantly in both schemes at one year no significant difference between schemes. Benefit score at one year revealed that the patients in DFU scheme received significantly higher amount of benefits compared to MFU scheme. In conclusion daily instruction has significantly motivated the patient and his/her family bringing a new hope.     

Growth of the jugular lymph sacs and establishment of the topography of the cervical portion of the thoracic duct during early human ontogenesis

In 196 human embryos, prefetuses, fetuses and newborns, by means of a complex of morphological methods, development of the jugular lymphatic sacs and the process of settling of the thoracic duct cervical part topography have been studied. The jugular lymphatic sac anlages take place on the 6th week of the development. From the lymphatic cleft, situating in the mesenchyme near the anterior cardinal veins, multichambered cavities laid with endotheliocytes are forming,--the jugular lymphatic sacs. Connection of the initially close lymphatic sacs with the venous system takes place secondarily by the end of the embryonic period of development. In the area of the sac ostia a valve is formed, that makes morphological premises for unidirected lymph flow into the venous system. The lymph nodes developing at the place of the reducing jugular lymphatic sacs, ensure formation: from the left jugular lymphatic sac--the cervical part of the thoracic duct, from the right jugular lymphatic sac--the right lymphatic duct and the jugular and the subclavicular lymphatic trunks. Variability in the form and topography of these structures are determined both by the form and construction of the jugular lymphatic sacs and by developmental peculiarities of the lymph nodes at their place. The process of settling of the thoracic duct cervical part topography depends on age changes of its size and form, as well as on development of structures situating nearby, and by the time of birth it is not completed.     

Lymphovenous shunts in man

Lymphovenous shunts have been detected in patients by lymphography with Ultrafluid Lipiodol. No shunts were found in patients with normal lymphatic systems. They were found in patients with lymphoedema, with lymph nodes involved by malignant disease, and in patients who had had surgical interruption of lymphatic pathways, either vessels or nodes. The total incidence of lymphovenous shunts in 700 lymphographic studies was 2·3%. The incidence in the various pathological groups was highest in those with obvious lymph node involvement.In certain situations, particularly primary lymphoedema, the role of a lymphovenous shunt appears favourable to prognosis. In other situations a deleterious effect may be produced.     

肝淋巴水肿的超微结构及实验治疗研究

４２只新西兰兔,随机分为正常对照组、手术组与治疗组,后两组行胸导管结扎术,治疗组术后腹腔注射苯毗哺酮,并做血清生化指标检查及光、电镜观察。手术组动物光镜下淋巴管、微静脉肿胀扩张,内皮细胞可见溶解破坏,Ｄｉｓｓｅ间隙扩张,出现淋巴管—静脉—胆管瘘;肝细胞肿胀,核缩小减少。电镜下,淋巴管、静脉及微胆管内皮细胞明显缺损,线粒体空泡化,间质组织纤维化。血清化验显示ＧＯＴ、ＧＧＴ升高,而总蛋白降低,尤以白蛋白降低明显。而治疗组动物光镜及电镜下结构病理变化轻微,但淋巴管内皮细胞开放连接明显增加;血清生化指标与正常对照组无明显区别,但血中ＷＢＣ和嗜酸性粒细胞数量增加。电镜下,枯否氏细胞增加,并有活跃的伪足,表明苯吡喃酮可刺激体内巨噬细胞的生长,增加机体免疫能力。     

Lifestyle modifications to prevent and control hypertension. 1. Methods and an overview of the Canadian recommendations. Canadian Hypertension Society,Canadian Coalition for High Blood Pressure Prevention and Control,Laboratory Centre for Disease Control at Health Canada,Heart and Stroke Foundation of Canada

OBJECTIVE: To provide updated, evidence-based recommendations for health care professionals on lifestyle changes to prevent and control hypertension in otherwise healthy adults (except pregnant women). OPTIONS: For people at risk for hypertension, there are a number of lifestyle options that may avert the condition--maintaining a healthy body weight, moderating consumption of alcohol, exercising, reducing sodium intake, altering intake of calcium, magnesium and potassium, and reducing stress. Following these options will maintain or reduce the risk of hypertension. For people who already have hypertension, the options for controlling the condition are lifestyle modification, antihypertensive medications or a combination of these options; with no treatment, these people remain at risk for the complications of hypertension. OUTCOMES: The health outcomes considered were changes in blood pressure and in morbidity and mortality rates. Because of insufficient evidence, no economic outcomes were considered. EVIDENCE: A MEDLINE search was conducted for the period January 1996 to September 1996 for each of the interventions studied. Reference lists were scanned, experts were polled, and the personal files of the authors were used to identify other studies. All relevant articles were reviewed, classified according to study design and graded according to level of evidence. VALUES: A high value was placed on the avoidance of cardiovascular morbidity and premature death caused by untreated hypertension. BENEFITS, HARMS AND COSTS: Lifestyle modification by means of weight loss (or maintenance of healthy body weight), regular exercise and low alcohol consumption will reduce the blood pressure of appropriately selected normotensive and hypertensive people. Sodium restriction and stress management will reduce the blood pressure of appropriately selected hypertensive patients. The side effects of these therapies are few, and the indirect benefits are well known. There are certainly costs associated with lifestyle modification, but they were not measured in the studies reviewed. Supplementing the diet with potassium, calcium and magnesium has not been associated with a clinically important reduction in blood pressure in people consuming a healthy diet. RECOMMENDATIONS: (1) It is recommended that health care professionals determine the body mass index (weight in kilograms/[height in metres]2) and alcohol consumption of all adult patients and assess sodium consumption and stress levels in all hypertensive patients. (2) To reduce blood pressure in the population at large, it is recommended that Canadians attain and maintain a healthy body mass index. For those who choose to drink alcohol intake should be limited to 2 or fewer standard drinks per day (maximum of 14/week for men and 9/week for women). Adults should exercise regularly. (3) To reduce blood pressure in hypertensive patients, individualized therapy is recommended. This therapy should emphasize weight loss for overweight patients, abstinence from or moderation in alcohol intake, regular exercise, restriction of sodium intake and, in appropriate circumstances, individualized cognitive behaviour modification to reduce the negative effects of stress. VALIDATION: The recommendations were reviewed by all of the sponsoring organizations and by participants in a satellite symposium of the fourth international Conference on Preventive Cardiology. They are similar to those of the World Hypertension League and the Joint National committee, with the exception of the recommendations on stress management, which are based on new information. They have not been clinically tested. SPONSORS: The Canadian Hypertension Society, the Canadian Coalition for High Blood Pressure Prevention and Control, the Laboratory Centre for Disease Control at health Canada, and the Heart and Stroke Foundation of Canada.     

Molecular regulation of lymphangiogenesis and targets for tissue oedema.

New insight has recently been obtained into the molecular mechanisms regulating the function of lymphatic endothelial cells. Vascular endothelial growth factors-C and -D have been shown to stimulate lymphangiogenesis, and their receptor VEGFR-3 has been linked to human hereditary lymphoedema, although there is evidence that other genes are also involved. These data suggest that it may become possible to stimulate lymphatic growth and function and to treat tissue oedema involved in many diseases.     

Lymphatic filariasis in children: clinical features, infection burdens and future prospects for elimination

Lymphatic filariasis (LF), a common parasitic infection in tropical countries, causes lymphoedema of limbs, hydrocele and acute attacks of dermato-lymphangio-adenitis. Recent advances in diagnosis have helped to recognize that LF infection is often acquired in childhood. Newly available diagnostic techniques like sensitive antigen and antibody assays, Doppler ultrasonography and lymphoscintigraphy have helped to understand the subclinical pathology caused by this infection, which was hitherto generally believed to be irreversible. Recent studies indicate that drugs used in the mass drug administration (MDA) programme under GPELF are capable of reversing the sub-clinical lymphatic damage in children and provide benefits other than interruption of transmission. Albendazole and ivermectin used in MDA are effective against soil-transmitted helminthic infections common in children in LF endemic areas. Thus MDA had other 'beyond LF' benefits in treated children including increased appetite, weight gain, greater learning ability and concentration, better school attendance and prevention of anaemia. MDA should no longer be viewed as a measure for interrupting transmission alone. Recent findings of reversibility of early lymphatic pathology in treated children indicate that both MDA and 'foot-hygiene' measures are effective strategies in preventing and managing morbidity. Programme managers should effectively utilize this information to strengthen their advocacy efforts to achieve high and sustainable coverage in MDA.     

Stakeholder perspectives on an integrated package of care for lower limb disorders caused by podoconiosis,lymphatic filariasis or leprosy: A qualitative study

BackgroundLower limb disorders including lymphoedema create a huge burden for affected persons in their physical and mental health, as well as socioeconomic and psychosocial consequences for them, their families and communities. As routine health services for the integrated management and prevention of lower limb disorders are still lacking, the ‘Excellence in Disability Prevention Integrated across Neglected Tropical Diseases’ (EnDPoINT) study was implemented to assess the development and delivery of an integrated package of holistic care–including physical health, mental health and psychosocial care–within routine health services for persons with lower limb disorders caused by podoconiosis, lymphatic filariasis and leprosy.Methodology/Principal findingsThis study was part of the first of three phases within EnDPoINT, involving the development of the integrated care package. Focus group discussions and key informant interviews were undertaken with 34 participants between January–February 2019 in Awi zone, Ethiopia, in order to assess the draft care package’s feasibility, acceptability and appropriateness.Persons affected by lower limb disorders such as lymphoedema experience stigma, exclusion from families, communities and work as well as physical and financial hardship. Beliefs in disease causation inhibit affected persons from accessing care. Ignorance was a barrier for health care providers as well as affected persons. Training and education of affected persons, communities and caregivers is important in improving care access. It also requires time, space, materials and financial resources. Both top-down and grass roots input into service development are key, as well as collaboration across stakeholders including charities, community leaders and “expert patients”.Conclusions/SignificanceThis study highlighted the need for the EnDPoINT integrated care package and provided suggestions for solutions according to its three aspects of integrated care (integration into routine care; integration of mental health and psychosocial care; and integration of care across the three diseases), thereby giving support for its feasibility, acceptability and appropriateness.     

Structural and ultrastructural changes of lymph nodes in primary lymphoedema

Optical and electronmicroscopic investigations of the inguino-iliac lymph nodes and lymphatic vessels of the lower limb suggested a pathogenic role of lymph node structural alterations in primary lymphoedema. Most of the investigated lymph nodes showed an extensive fibrosis frequently associated with lipomatosis ectasy of medullary sinuses, a.o., estimated as primary lesions appearing on a genetically propensic ground or by developmental anomalies. Alteration of the lymphatic vessel intima, proliferation, muscle hypertrophy, subintimal fibrohyalinosis, a.o., occurred in consequence of the impeded lymphatic drainage by the primary lymph node fibrosis.     

Gene expression profile of lymphatic endothelial cells

The lymphatic system was first described at around the same time as the blood circulation centuries ago, but the biological function elucidation of LECs (lymphatic endothelial cells) is far less than that of BVECs (blood vascular endothelial cells). Since the discovery of molecular markers for LECs and exploration of lymphatic role in tumour metastasis, more attention has been given to basic lymphatic research. Approx. 150 known genes were found to be expressed at the mRNA and protein levels by LECs. These molecules play an important role in lymphangiogenesis, signalling, tumour metastasis, immune function and fluid transport. This review provides a brief outline of gene expression profile of LECs and the molecular biological function, which will give the reader a better understanding about the mechanics of lymphatic function and some pathologies related to the lymphatic system such as lymphoedema, and facilitate advanced scientific research into lymphatic biology.