Comparison of breast milk sodium‐potassium ratio, pro‐inflammatory cytokines, and somatic cell count as potential biomarkers of subclinical mastitis (623.21)

• DOI: 10.1096/fasebj.28.1_supplement.623.21
• Publication Date: 2021-06-15T17:39:44Z
• Authors: Hilary Wren; Chen Li; Noel Solomons; Anne Marie Chomat; Marilyn Scott; Kristine Koski
• Keywords: 2. Zero hunger; 0303 health sciences; 03 medical and health sciences; 3. Good health

Background: SCM is an asymptomatic inflammatory condition of the lactating breast associated with infant growth faltering. A breast milk Na/K ratio >0.6 is the current indicator for SCM whereas in cows SCC is considered the ‘gold standard’. Our objective was to determine if potential biomarkers of human SCM (SCC, pro‐inflammatory cytokines) were associated with Na/K ratio at two stages of lactation.Methods: Breast milk samples were collected from 53 lactating Mam‐Mayan women with infants < 45d (early lactation) and 52 with infants 4‐6mo (late lactation). Inductively Coupled Plasma Mass Spectrometry measured Na and K. Flow Cytometry was used to measure SCC. Luminex measured 3 pro‐inflammatory cytokines (IL‐6, IL‐8, TNF‐α).Results: One‐fifth had a breast milk Na/K ratio >0.6; an elevated Na/K ratio was more common in early lactation (26%) compared to later lactation (15%). By contrast, both IL‐8 (10.3 vs 38.3 pg/mL) and SCC (313K vs 457K cells/mL) were lower in early verses later lactation. The Na/K ratio was positively correlated with all 3 pro‐inflammatory cytokines in early lactation whereas only IL‐8 was associated in later lactation. SCC was not correlated with either Na/K ratio or pro‐inflammatory cytokines in either stage of lactation.Conclusion: Potential biomarkers of SCM vary by stage of lactation. Based on the Na/K ratio, SCM is more prevalent during early lactation. Results suggest that pro‐inflammatory cytokines may emerge as possible biomarkers and that SCC may not be a useful biomarker of SCM in lactating mothers.Grant Funding Source: McGill University International Mobility Award, NSERC