New findings may help speed up treatment for UTIs in children

A study led by UT Southwestern and Child Health researchers outlines parameters for the number of white blood cells that must be present in children’s urine at different concentrations to treat urinary tract disease (UTI). ) to recommend. The findings, recently published in Pediatrics, it may help speed up the treatment of this common condition and prevent potential lifelong complications.

UTIs cause up to 7 percent of fever in children up to 24 months of age and are a common reason for visiting hospital emergency rooms. However, said study director Shahid Nadeem, MD, a pediatric assistant professor at UTSW as well as an emergency department physician and pediatric nephrologist at Dallas Children ‘s Medical Center, these bacterial infections in infants and toddlers can be difficult to diagnose. that their symptoms are similar to other conditions that cause fever.

If a diagnosis is delayed, he explains, UTI can become a serious disease that can cause lasting side effects. For example, UTI-associated renal scarring has been linked to hypertension and renal disease later in life.

To diagnose a UTI, doctors need to culture a urine sample and wait for it to show bacteria in a petri dish that contains nutrients. However, says Nadeem, this process can take up to two days, delaying treatment. As a result, he and other doctors usually rely on testing for urine for a white protein bound to a blood cell called leukocyte esterase (LE), then testing for blood cells white – a sign of immune activity – by looking for them in urine under a microscope.

In children, he says, the number of white blood cells can be quite variable, with some of this difference due to varying urine density. Therefore, it is not known what the white blood cell count threshold should be used to start treating a suspected UTI based on urine density.

To confirm these parameters, Nadeem and his colleagues examined medical records of children younger than 24 months who were taken to the emergency department at the Children’s Medical Center between January 2012 and December 2017 with suspected UTI and both urinalysis. their – in which their urine density and presence of LE and white blood cells were assessed – and urine culture. The study turned up 24,171 patients, 2,003 of whom were diagnosed with UTI based on urine culture.

Using the unique graph of their urine – urine relative to water density, a measure that serves as a collection point for density – and the number of white blood cells present in a high-powered microscope, the researchers up with cut-off points for three urine collection groups: For low urine density, children only needed three white blood cells to suspect a UTI; for medium density, that number was six; and for high densities, it was eight.

For each of these collection groups, leukocyte esterase remained stable, says Nadeem – suggesting that it is a good stimulant for urine analysis for the presence of white blood cells.

Knowing the number of white blood cells that are likely to be present in urine samples at different concentrations in children with UTIs may help physicians treat these diseases before they get urine culture results, he said, relieving patients and their parents and preventing complications.

“The sooner we can start treatment, the better for these young patients,” says Nadeem. “Our results add more information to doctors’ toolboxes to help them close to do this. “