For patients with rheumatoid arthritis (RA) who wish to conceive, the prevalence of anti-Sjögren's syndrome-related antigen A (anti-SSA) and anti-Sjögren's syndrome-related antigen B (anti-SSB) antibodies is low, according to a study published online July 8 in RMD Open.
Hieronymus T. W. Smeele, M.D., from the Erasmus Medical Center in Rotterdam, Netherlands, and colleagues examined the prevalence and titers of anti-SSA and anti-SSB autoantibodies in patients with RA with a wish to conceive from two large cohorts.
The researchers found that 26 of the 647 patients with RA had detectable anti-SSA and/or anti-SSB: Anti-SSA was detected in 25 patients and anti-SSB in seven patients (3.9 and 1.1 percent, respectively). For anti-SSA antibodies, 13 of the women had a titer of >240 units/mL. Compared with rheumatoid factor (RF)-negative patients, RF-positive patients had a higher prevalence of anti-SSA and/or anti-SSB (5.1 versus 1.6 percent). In the offspring, there were no cases of congenital heart block (CHB) and/or neonatal lupus syndrome. The prevalence of RA in mothers with SSA-related CHB was 1.5 percent in the French national register.
"If our findings could be replicated in other studies, it is justified to critically review the current guidelines. Especially since the practical consequences of finding these antibodies is currently questioned," the authors write. "In particular, for RF-negative patients, the current advise to test for both anti-SSA and anti-SSB can be reconsidered."
The kits for measurement of anti-SSA and anti-SSB were gifted from Thermo Fischer Scientific.