The most common first diagnosis of Alport syndrome in Japan is during the universal age-3 urine screening. In 60% of these children, the disease had already progressed far enough to qualify for treatment. Therefore, universal early-age urinalysis may be an apt means for both better prognoses and reduced costs of medical care.
Alport syndrome is a genetic disease that affects about one in 5,000 people. Patients cannot produce a certain type of collagen which leads to kidney failure, and may also lead to hearing loss and changes in the eye. There is medication that delays the onset of kidney failure, after which patients need a kidney transplant or dialysis. However, while this works better the earlier the condition is identified, many people only become aware of the condition once kidney dysfunction has already set in.
"Japan conducts universal urinalysis screening at age 3, but no large-scale studies have been conducted to evaluate its effectiveness at identifying Alport syndrome in children," says Kobe University pediatrician ISHIMORI Shingo. He and his team thus turned to consenting Kobe University Hospital patients aged 18 and younger and diagnosed with Alport syndrome to find out how they were first diagnosed with the condition.
In the journal Kidney International Reports, they now present their results. They found that over 30% of patients, or 113 out of 356 patients, were referred to hospital for testing for Alport syndrome due to age-3 urine screening results, which was the most common reason for referral. In addition, 60% of these people already met the conditions for treatment. Ishimori says: "Our study revealed that a remarkably high proportion of 3-year-old children with Alport syndrome already required therapeutic intervention even though they were still asymptomatic. Consequently, the introduction of a urine testing system may allow for intervention before the onset of kidney dysfunction."
The Kobe University team is careful to note that while universal urinalysis was the most common trigger for detection and is thus promising, this does not tell how effective the approach is at identifying people with the condition among the whole population. The team estimates that the number of Japanese children who underwent screening during the period that would make them eligible for their study was roughly 23 million, and it is currently unknown what fraction of these was correctly diagnosed with the condition.
"Future investigations should assess the diagnostic yield of the current approach. But we now know that implementing a screening system that facilitates early detection and enables early intervention might offer considerable benefits," says Ishimori. These benefits extend not only to an improved quality of life for the affected patients, but also to healthcare economics by reducing the burden of end-stage kidney failure management, such as through dialysis or kidney transplants. The Kobe University researcher concludes, saying, "Since many countries do not have universal urinalysis screening at the age of 3, and not even all municipalities in Japan conduct the relevant tests for Alport syndrome, our findings should promote the wider adoption of measures leading to earlier detection and earlier treatment."
This research was funded by the Japan Society for the Promotion of Science (grant 23K07698), Health, Labour and Welfare Sciences Research Grants (grant 23FC1047) and the Japan Agency for Medical Research and Development (grants 24015773, 22810094, 23ek0109617s1702).
Kobe University is a national university with roots dating back to the Kobe Higher Commercial School founded in 1902. It is now one of Japan's leading comprehensive research universities with nearly 16,000 students and nearly 1,700 faculty in 11 faculties and schools and 15 graduate schools. Combining the social and natural sciences to cultivate leaders with an interdisciplinary perspective, Kobe University creates knowledge and fosters innovation to address society's challenges.
