Researchers studied blood samples from 17 children with a kidney disease called nephrotic syndrome to find markers that could help doctors track when the disease gets worse or better. They measured several substances in the blood, including proteins and vitamins, at different stages of the illness. The study found that certain vitamins and proteins changed levels depending on whether the disease was active or in remission. These findings suggest that simple blood tests might one day help doctors better understand and monitor this kidney condition in children, though more research is needed to confirm these results.

The Quick Take

  • What they studied: Whether certain substances found in blood could help doctors tell when a child’s kidney disease is getting worse or better
  • Who participated: 17 children (15 boys and 2 girls) with idiopathic nephrotic syndrome, a condition where the kidneys leak protein into the urine
  • Key finding: Three vitamins (E, A, and D) and one protein (ECP) showed different levels in the blood depending on whether the disease was active or in remission, suggesting they might be useful markers for tracking disease activity
  • What it means for you: This research suggests that doctors might eventually use simple blood tests to better monitor kidney disease in children, but these findings are preliminary and need to be tested in larger groups of children before being used in regular medical care

The Research Details

This was a prospective study, meaning researchers followed the same children over time and collected blood samples at different points in their illness. The team collected blood from 17 children with nephrotic syndrome at three key times: when the disease first appeared or came back, when the disease went into remission (got better), and after they stopped taking steroid medications. They measured specific substances in the blood using standard laboratory methods and compared the results using statistical analysis to see if the levels changed at different stages of the disease.

The researchers were looking for ‘biomarkers’—substances in the blood that change when a disease is active or improving. They tested for three things: a protein called eosinophilic cationic protein (ECP), several vitamins (A, D, and E), and antibodies against a kidney protein called nephrin. These substances were chosen because previous research suggested they might be involved in how nephrotic syndrome develops.

The study took place at a single medical center in Slovenia, and the researchers carefully tracked each child’s blood samples over time to see how these substances changed as the disease progressed or improved.

Understanding what happens in the blood during different stages of kidney disease is important because it could help doctors better diagnose the condition, predict when it might get worse, and track whether treatments are working. Currently, doctors mainly rely on urine tests and kidney function measurements, so finding additional blood markers could give them more tools to care for children with this condition.

This study is relatively small (only 17 children), which means the findings are preliminary and need to be confirmed in larger groups. The study was well-designed in that it followed the same children over time and collected samples at specific disease stages, which is stronger than just comparing different groups of children. However, because it was conducted at only one medical center, the results may not apply to all children with this condition. The researchers used standard laboratory methods, which is reliable, but the small sample size means we should be cautious about drawing firm conclusions.

What the Results Show

The study found that a protein called ECP (eosinophilic cationic protein) was highest in the blood when the disease first appeared or came back, and lower when the disease improved. This suggests ECP might be a useful marker for knowing when the disease is active.

Vitamin E levels were lowest when the disease went into remission after steroid treatment, while vitamin A levels were highest at remission. Vitamin D was decreased at multiple stages: when the disease started, when it relapsed, and even when it went into remission. These changing vitamin levels suggest that the body’s vitamin balance may be affected by this kidney disease.

Interestingly, the researchers did not find antibodies against nephrin (a kidney protein) in any of the blood samples, even though some previous research suggested these antibodies might play a role in the disease. This finding was unexpected and suggests that this particular antibody may not be important in children with this type of kidney disease.

The pattern of vitamin changes was noteworthy because it showed that different vitamins behaved differently at different stages of the disease. The fact that vitamin D was low at multiple stages suggests it might be consistently affected by the disease, while vitamins A and E showed more specific changes related to remission. These patterns could eventually help doctors understand the disease better and potentially guide treatment decisions.

Previous research had suggested that anti-nephrin antibodies might play a role in nephrotic syndrome, but this study did not find them in any of the children studied. This finding contradicts some earlier research and suggests that the disease may work differently in children than in adults, or that these antibodies may not be universally important in all cases of nephrotic syndrome. The findings about vitamins and ECP are consistent with the idea that inflammation and immune system changes are involved in the disease, which aligns with current understanding of how nephrotic syndrome develops.

The biggest limitation is the small number of children (only 17), which means the results may not apply to all children with this condition. The study was conducted at only one medical center in Slovenia, so the findings may be specific to that population. The study did not include a control group of healthy children for comparison, which would have helped show how different these blood markers are in children with the disease. Additionally, the study did not look at whether these blood markers could predict which children would relapse or respond better to treatment, which would be important for practical use in the clinic.

The Bottom Line

Based on this preliminary research, there are no new treatment recommendations for patients at this time. The findings suggest that blood tests measuring ECP and vitamins A, D, and E may eventually be useful for tracking disease activity, but more research in larger groups of children is needed before these tests can be recommended for routine clinical use. If you have a child with nephrotic syndrome, continue following your doctor’s current monitoring plan with urine tests and kidney function measurements.

This research is most relevant to children with idiopathic nephrotic syndrome and their families, as well as pediatric kidney specialists. Parents of children with this condition should be aware that researchers are working to find better ways to monitor the disease. However, these findings are too preliminary to change current medical practice. This research is less relevant to adults with nephrotic syndrome, as the disease may behave differently in adults.

This is early-stage research, so it will likely take several years of additional studies before any new blood tests based on these findings could be available for regular clinical use. Researchers will need to confirm these findings in larger groups of children and determine whether these blood markers can actually predict disease activity or treatment response before they become part of standard medical care.

Want to Apply This Research?

  • If you have a child with nephrotic syndrome, track the dates and results of blood tests measuring vitamin D, vitamin E, and vitamin A levels alongside disease activity notes (active disease, in remission, or relapse). Record these alongside urine protein levels and steroid medication doses to see patterns over time.
  • Work with your child’s doctor to ensure adequate vitamin intake, particularly vitamin D and E, which this research suggests may be affected by the disease. Keep detailed records of when blood tests are done and what the results show, which can help your medical team identify patterns in your child’s disease activity.
  • Create a timeline in the app showing your child’s disease stages (onset, remission, relapse) alongside blood test dates and results. This visual record can help you and your doctor identify patterns and prepare for upcoming appointments. Set reminders for scheduled blood work and medication changes, and note any symptoms that appear before disease activity changes.

This research is preliminary and based on a small study of 17 children. These findings should not be used to change current medical treatment or monitoring of nephrotic syndrome. If your child has been diagnosed with nephrotic syndrome, continue following your doctor’s recommendations for treatment and monitoring. Do not start, stop, or change any medications or supplements based on this research without first consulting your child’s nephrologist or pediatrician. Blood tests for these biomarkers are not yet recommended for routine clinical use. Always discuss any concerns about your child’s kidney health with a qualified healthcare provider.