Dental therapy in children with PID

Primary Immunodeficiencies (PID) arise from rare genetic defects affecting humoral and cellular immunity, which can lead to reduced dental plaque control. This study aimed to characterize the subgingival dental plaque microbiome in neutropenic PID children compared to healthy controls and assess their response to non-surgical periodontal therapy. Subgingival plaque was collected from 3 first molars and 1 first incisor at baseline and 6 months post-therapy from children with PID (n=24) and systematically healthy control participants (n=25). The subgingival microbiome was profiled using an Illumina metabarcoding approach on the bacterial 16S rRNA gene V1-V2 region. Significant shifts in community structure were observed post-therapy, measured by alpha and beta diversities. Increase in Rothia spp., Neisseria spp., and Actinomyces spp. was noted in PID children post-therapy, consistent with clinical improvements. Baseline blood absolute neutrophil counts in PID children were positively associated with Streptococcus cristatus and Gemella spp., and negatively with Saccharibacteria, Capnocytophaga, and Porphyromonas spp., highlighting key host-microbial relationships. Non-surgical periodontal therapy ameliorated dysbiosis in neutropenic PID children, revealing novel host-microbial interactions important for oral microbiome in health.原发性免疫缺陷病（Primary Immunodeficiencies, PID）是一类罕见的遗传性免疫缺陷疾病，可累及体液免疫与细胞免疫，进而导致牙菌斑控制能力受损。本研究旨在明确中性粒细胞减少型PID患儿的龈下牙菌斑微生物组特征，并以健康个体作为对照，同时评估其对非手术牙周治疗的响应效果。研究分别于基线及治疗后6个月，从24名PID患儿与25名系统健康对照者的3颗第一磨牙及1颗第一切牙处采集龈下菌斑样本。采用Illumina宏条形码测序技术，针对细菌16S rRNA基因V1-V2可变区对龈下微生物组进行特征分析。通过α多样性与β多样性分析发现，治疗后菌群群落结构发生显著改变。治疗后PID患儿的罗氏菌属（Rothia spp.）、奈瑟菌属（Neisseria spp.）及放线菌属（Actinomyces spp.）相对丰度显著升高，该变化与临床症状改善情况一致。基线状态下，PID患儿的外周血中性粒细胞绝对计数与嵴链球菌（Streptococcus cristatus）、孪生球菌属（Gemella spp.）丰度呈正相关，与糖细菌门（Saccharibacteria）、噬二氧化碳纤维菌属（Capnocytophaga）及卟啉单胞菌属（Porphyromonas spp.）丰度呈负相关，揭示了关键的宿主-微生物互作关系。非手术牙周治疗可改善中性粒细胞减少型PID患儿的口腔菌群失调状态，本研究揭示了对口腔健康微生物组至关重要的新型宿主-微生物互作机制。