This glomerular disease occurs mainly in Asia. It was first described by Takao Saito in 1989. The doctor described the case of a patient diagnosed with nephropathy due to lipid disorders.
Lipoprotein glomerulopathy is a very rare disease. Until 2006, only 65 cases of this disease were described. The disease is a consequence of abnormalities in certain genes that determine the presence of inappropriate apolipoprotein E in the body. In other words, abnormal lipoproteins accumulate in the glomeruli. This results in the appearance of nephrotic syndrome with progressive loss of glomerular filtration function.
Symptoms of glomerulopathy
People who develop nephrotic syndrome experience swelling of the face (mainly around the eyes) in the morning and swelling of the lower legs that increase when standing. Swelling is greatest in the evening. Initially, the swelling appears from time to time. Sometimes they form quickly, increasing and in a few days lead to a significant increase in body weight, even by several kilograms.
In severe cases, in addition to swelling of the whole body, fluid accumulates in the abdominal cavity (so-called ascites) and pleural cavities. Patients have no appetite and feel very weak. The nephrotic syndrome may also develop arterial hypertension and symptoms of renal failure – acute or chronic.
Complications may include infections and venous or arterial thrombosis (as urine also loses antibodies and proteins that regulate blood clotting). A common abnormality is also high serum cholesterol and triglyceride levels.
In lipoprotein glomerulopathy, the glomerular filtration function deteriorates over time. Red blood cells appear in the urine, but not so many of them that they can change the color of urine.
Damage to mesangial cells (part of the kidney body, a type of connective tissue located between vessels) and their secondary proliferation probably lead to an increase in the number of receptors that are responsible for lipoprotein uptake, and thus to the excessive accumulation of these abnormal compounds, then transferred to the lumen of the vessels capillaries, causing them to inflate.
Diagnosis of the disease
Sometimes it is not possible to make a correct diagnosis only on the basis of the patient’s observation and laboratory results. It is necessary to take a sample of the kidney and examine the sample by a histopathologist. Tissue is assessed under a light and electron microscope. The researcher will notice a characteristic granular mass that fills the vascular spaces and causes the enlargement of the renal glomeruli.
Treatment
So far, no methods have been developed to treat the causes of lipoprotein glomerulopathy. Treatment is about managing the symptoms of proteinuria and preventing kidney failure. When they are significantly weakened and cannot cleanse the blood properly, renal replacement therapy, i.e. dialysis, is introduced. Kidney transplantation is not an ideal solution in this case, because after it is performed, in many cases the disease recurs and the kidney damage and failure reappear.
Tekst: Anna Jarosz