A case report recently demonstrated that a correct diagnosis of Alport disease is crucial, but it may be difficult to distinguish from thin basement membrane disease — a similar kidney condition that doesn’t progress to kidney failure — and even biopsies can give inconclusive results.
The study, “An Overlapping Case of Alport Syndrome and Thin Basement Membrane Disease,” published in the Journal of Clinical Medicine Research, underscored the importance of a correct diagnosis, not only to monitor a patient for disease progression, but also to allow screening and early interventions among family members of a patient.
Researchers at Avalon University School of Medicine in Curacao and Raleigh General Hospital in Beckley, West Virginia, described a 48-year-old man who sought care for flank pain on his right side. The man also reported blood in his urine for more than 10 years. He had a 10-year-old daughter who also showed signs of blood in her urine.
The man also had experienced progressive loss of his hearing and had decreased vision. Lab test did not reveal anything abnormal in his blood or urine. An ultrasound showed that his kidneys looked normal, and physicians performed a biopsy.
The tissue examination showed changes resembling thin basement membrane disease, with thinner and thicker parts of the basement membrane of glomeruli — the membrane over which urine is filtered from the blood. The tissue also had normal structures of collagen IV alpha-5 chains, which is rare in Alport disease.
Thin basement membrane disease is also inherited, and is far more common than Alport disease, with reports stating that up to 5 percent of the population may be affected. The condition resembles Alport, although the kidney problems are not progressive.
Compared to patients with Alport disease, those with thin basement membrane disease do not develop hearing or sight problems. Based on these observations, doctors diagnosed the patient with Alport, despite a biopsy that did not show typical Alport changes, and that despite his age, he had not developed more severe kidney problems.
Since Alport is a progressive disease that ultimately leads to kidney failure, it is crucial to discriminate between the conditions, since other family members may be affected.