Filarial Nephropathy - Symptoms, Causes, Diagnosis, and Treatment

What Is Filariasis?

Filariasis is a disease affecting the lymphatic system and the cutaneous tissues of the body. It is mostly found in tropical countries. It is caused by a parasite named Wuchereria bancrofti, which belongs to the family ‘filaria’. The parasite needs a vector to get transmitted to humans. Aedes and Anopheles mosquitoes act as a vector to transmit the disease. Filariasis is also called lymphatic filariasis, as it affects the lymphatic system of the body. Patients infected with filariasis may not show any external symptoms or signs of infection and thus remain asymptomatic. The worms of filariasis can remain alive inside the body for six to eight years producing larvae. However, there can be a lot of damage to the lymphatic system.

The early symptoms include swelling at different places of the body and inflammation. Severe inflammation can be seen in lymph nodes, lymphatic vessels, and the skin. In the advanced stages, swelling and inflammation in the genital and lower extremities can be seen. The size of the swollen parts is seen as larger than their normal size.

What Is Nephropathy?

Nephropathy is the destruction of renal function. Nephropathy can be caused by various systemic diseases. The diseases affecting kidney function are diabetes mellitus, high blood pressure, filariasis, malaria, hepatitis B or C infection, and human immunodeficiency virus infection. These chronic diseases, when left untreated, have an adverse effect on kidney function. In nephropathy, there is impairment in renal function due to the damage to the nephrons, which are the filtering units of the kidney. Nephropathy, when left untreated, can lead to kidney failure.

The various signs and symptoms of nephropathy are itchy skin around the arms or back of the body, shortness of breath-apnea, insomnia-trouble in sleeping, problems with urination, cramps in muscles, swelling in the face, feet, hands, and legs, nausea and vomiting.

What Are the Symptoms of Filarial Nephropathy?

• Kidney involvement in filariasis can be characterized by the presence of chyluria or milky urine.

• Hematuria (presence of blood in the urine, which is caused by the filarial worm obstruction inside the lymphatic system).

• Lymphoedema (inflammation of the lymphatic tissues).

• Glomerulonephritis (inflammation of the nephrons of the kidney).

• Pulmonary eosinophilia (increase in the pulmonary red blood cell count).

• Pruritus (itchy skin).

• Pain in the abdomen.

• Myalgia (pain in muscle).

• Swelling under the skin.

• Swelling in the genital reading to elephantiasis.

• Hepatomegaly (enlarged liver).

• Spleenomegaly (enlarged spleen).

How to Diagnose Filarial Nephropathy?

1. Blood Smear Examination - The best method to diagnose filariasis is an examination of the blood smear under the microscope for the presence of microfilariae. The micro-filariae circulates in the blood during the night time, so the best time to collect the blood sample is during the night. The blood is stained with hematoxylin and eosin.

2. Serologic Examination - It can be used for the detection of microfilariae in blood to confirm lymphatic filariasis. It can also provide results for high levels of IgG4 antibody, which increase only in patients with active filarial infection. Proteinuria and chyluria can be detected in blood tests.

3. Tests to Check Lymphoedema - Lab tests can show negative results to detect lymphoedema as it develops in the later stages.

4. Urine Analysis - This test can provide results for the presence of protein and red blood cells in the urine, creatinine clearance, albumin/creatinine ratio, urine specific gravity, total urine protein, and uric acid in the urine.

5. Blood Analysis - This test is used to diagnose the high level of creatinine, decrease in the number of RBCs-eosinopenia, abnormal albumin, and blood urea nitrogen levels, increased serum electrolyte potassium, and decreased sodium level can be found.

6. Computed Tomography (CT) Scan and Kidney Ultrasound: To check the size of a kidney or for the presence of any blockages in the kidney vessels and urinary tract a kidney ultrasound or CT scan can be used.

7. Kidney Biopsy - Fine needle aspiration cytology can be done to remove a piece of renal tissue by inserting a needle inside it. Biopsy indicates the portion of involved glomeruli and the presence of hypercellularity.

How to Treat Filarial Nephropathy?

Once the diagnosis has been made for filariasis, the physician will start the treatment based on the severity of the disease. The infection starts with an asymptomatic phase in which the patient does not show any external symptoms or signs of infection. Early symptoms include swelling and inflammation, which is painful. In advanced cases, there is a chance of permanent disability.

• To Treat Acute Cases - In the treatment modality of treating filarial nephropathy is to reduce or kill the microfilariae from the blood and lymphatic tissue. Medications to kill the filarial worms include a combination of one or more of the three drugs- Albendazole, Ivermectin, and Diethylcarbamazine.

• To Treat Chronic Cases - Chronic conditions affecting the lymphatic system can cause permanent disability if left untreated. Lymphatic drainage can be done in order to correct the lymphatic system. The drug of choice for treating filariasis is Diethylcarbamazine citrate (DEC) which is microfilaricidal and active against the adult worm.

What Are the Preventive Measures for Filarial Nephropathy?

• Vaccinations are currently unavailable for filariasis. So preventing mosquito bites can help. Covering your body by wearing long sleeve shirts and trousers can prevent mosquito bites.

• Strong perfume can draw the attention of mosquitoes, so avoid using them. Mosquito repellent creams can prevent mosquito bites.

• Mosquito mesh nets can be used at home for mosquito bite prevention.

• Initial stages of filariasis are asymptomatic, so any prevention from the disease worsening can be done by early diagnosis.

• Avoid food containing milk and milk products, sweets, contaminated water, fish, and jaggery while suffering from the infection.

Conclusion

As the early stages of filariasis cannot be diagnosed easily, one should always avoid getting infected by preventing mosquito bites. Avoiding contaminated food from markets can reduce the risk of being infected. Mosquito repellent creams should be used to check mosquito bites. Dietary changes during the infection should be made. Milk and milk products should also be avoided during the course of the infection. Elephantiasis in males can be treated and corrected by lymphatic drainage. Prevention of getting the genitals infected is essential.