Study Estimates Prevalence of BK Virus in Pediatric SLE Patients

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by Kara Elam |

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BK virus in lupus patients

Pediatric patients with systemic lupus erythematosus (SLE) may have a higher prevalence of detectable dormant BK virus (BKV) than the general population.

These are the findings from the study, “BK viruria and viremia in children with systemic lupus erythematosus,” recently published in the journal Pediatric Rheumatology.

BKV infections most often happen during early childhood, usually without any detectable symptoms. After infection, the virus goes into a dormant state, known as latent infection, in the genitourinary tract and can be reactivated if the patient is receiving immunosuppressive drugs or has a compromised immune system, like that associated with a diagnosis of SLE.

It is this dormant state with the threat of reactivation that researchers from the University of Florida Health wanted to explore in an effort to understand if SLE pediatric patients, with their already compromised immune system, could be at a higher risk of BKV reactivation, and the complications it may cause, namely severe renal dysfunction brought on by ureteric stenosis and hemorrhagic cystitis.

This is the first study to look at the prevalence of BK viruria or viremia in children with SLE. To accomplish the research aims, the investigators enrolled 32 pediatric SLE patients and took urine and blood samples from each patient at three-month time intervals up to one year after enrollment. The data analyzed included BKV detected in samples, clinical characteristics and medication history.

The results showed that during the enrollment period, 3.1% (one out of 32) of the study patients had BKV in their urine, known clinically as viruria; and 6.2% (two out of 32) of the study patients had BKV in their blood, known clinically as viremia. Throughout the study timeline these numbers changed so that by the end, three patients had viruria, five had viremia, and four had both viruria and viremia.  

Of the 12 patients with BKV reactivation, only one was positive for the minimal detectable amounts of blood in the urine, known as  microscopic hematuria. All others showed no observable symptoms.

The investigators observed no significant clinical difference between the study patients who did and did not have BKV reactivation regarding medication history and clinical characteristics.

“The current era of immunosuppression has begun to utilize more biologics, and children who have SLE are exposed to such agents at a younger age,” the researchers wrote. “Our study suggests that pediatric patients with SLE have BK viremia and/or viruria at a higher rate than the general healthy population, although the significance of the reactivation and viral level is unclear. The influence of immune-modulatory drugs on BKV reactivation is still uncertain.”

The researchers noted that due to the sample size of their study population, a larger study with a potential for a greater generalizability of the results is needed to thoroughly investigate the “interplay amongst BK virus, immunosuppression and dysregulated immune system”  in the SLE pediatric population.

Such a study may lead to better guidelines on the proper diagnosis and treatment of BKV in these patients.