Background/Purpose: Streptococcus pneumoniae (S. pneumoniae) may lead to severe life-threatening infections in both the general and immunocompromised population. Patients diagnosed with Systemic Lupus Erythematosus (SLE) are five times more likely to acquire invasive pneumococcal disease compared to healthy controls. There is a known association between nasopharyngeal (NP) pneumococcal colonization (NPcol) and increased risk of infection with S. pneumoniae. Therefore, the CDC recommends that patients with childhood onset SLE (cSLE) should receive both PCV13 and PPSV23 pneumococcal vaccines. Vaccine effect on pneumococcal NP colonization (VE-col) is suggested as a surrogate marker for protective vaccine effect against invasive pneumococcal infections, especially in young children. To date, no studies have examined the rate of NPcol in cSLE and how it correlates with vaccine immunity in this population. In our pilot study, we are assessing the rate and density of pneumococcal nasopharyngeal colonization following receipt of CDC-recommended pneumococcal vaccination in cSLE patients compared with age-matched healthy controls.

Methods: Case-control study of cSLE patients who have received CDC-recommended pneumococcal vaccines and healthy age-matched controls. Study was approved by local IRB. Participants were consented, study questionnaire provided, then NP swab samples collected and analyzed for quantitative pneumococcal PCR. The positive samples are saved for future study of specific serotypes. Rates of positive NP swabs are compared using chi-square or Fisher’s exact tests. A multivariable logistic regression model will be constructed to determine whether cSLE status is associated with higher likelihood of positive NP swabs while adjusting for possible confounders.

Results: We enrolled 40 cSLE patients and 41 healthy controls (HC). 40 cSLE were of median age 19 years (9y-24y), 31 (78%) females, 22 (55 %) white, 16 (38 %) African American (AA). 41 HC were of median age 19 years (9y-26y), 31 (76%) females, 31 (76 %) white, 2(5 %) African American (AA). NPcol were positive in 2/40 (5%) cSLE and in 0/41 (0%) HC. NPcol identified positive in 1 F (9y) and 1 M (23 y), both diagnosed with lupus nephritis, received immunosuppressive therapy (cyclophosphamide or mycophenolate mofetil and methylprednisolone) during and/or prior to their PCV13 or PPSV23 vaccinations.

Conclusion: Findings of only two positive NP swab sample was not expected as we have anticipated that patients with cSLE will have higher positive rates of NPcol compared to healthy controls. The two cSLE patients with identified positive NPcol were both diagnosed with lupus nephritis and were receiving high dose steroids and cylophosphamide or mycophenolate mofetil surrounding time of vaccination; however, without the PCR serotypes it is difficult to know if this represents vaccine conversion failure. As a next step, we plan to examine pneumococcal serotypes in positive samples to determine if the colonization is related to vaccine-related subtypes. Results of this study will help us better understand indirect markers for immune response to pneumococcal vaccination and to explore factors that may impact the response to pneumococcal vaccine in childhood lupus.

« Back to 2020 Pediatric Rheumatology Symposium

ACR Meeting Abstracts - https://acrabstracts.org/abstract/nasopharyngeal-pneumococcus-colonization-in-patients-with-childhood-onset-systemic-lupus-erythematosus-csle-compared-to-healthy-controls/