What Is the Association Between IgA Vasculitis and Serious Infection in Children?

Disease-specific factors may have a lasting effect on immune competence among children with immunoglobulin A vasculitis (IgAV), new research suggests.

“In patients with childhood IgAV, there is an increased long-term risk for a broader spectrum of infections, which is unrelated to serious infections prior to diagnosis or treatment,” the researchers wrote.

To make long-term observations of whether infections can trigger IgAV, the researchers evaluated the rates, types, and microorganisms for serious infection in children before and after their IgAV diagnosis. Infections were also evaluated in nonexposed controls. The study comprised 504 patients with IgAV (aged 5 years, 59.1% boys) and 1281 controls (aged 6 years, 66% boys). The 2 groups were matched for age, gender, and year of presentation.

The researchers estimated patients’ incidence rate (IR) for serious infection per 1000 person-months.

Time zero was the date of IgAV diagnosis or equivalent date among the controls, lookback (median 38 months) was the period prior to time zero, and follow-up (median 239 months) was the period after time zero.

During lookback, the prevalence of serious infection was similar among patients with IgAV (11.5%) and controls (9.5%). However, during this time, patients with IgAV had a higher rate of upper respiratory tract infections, with an IR ratio (IRR) of 1.79. These patients also had a shorter time between first serious infection and time zero (27 months) than the controls (43 months).

During follow-up, patients were at a constant increased risk for serious infections (IRR 1.46). IRRs of sepsis (12.6), pneumonia (6.19), upper respiratory tract infections (2.36), and skin infections (1.85) were higher during follow-up.

According to the researchers, there was little overlap between patients with serious infections in the lookback and follow-up periods.

—Colleen Murphy

Reference:

Nossent JC, Raymond W, Keen H, Preen DB, Inderjeeth CA. Infection rates before and after diagnosis of IgA vasculitis in childhood: a population-wide study using non-exposed matched controls. J Rheumatol. 2020;47(3):424-430. https://doi.org/10.3899/jrheum.190110.