Hematology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122, Milan, Italy.
Department of Oncology and Oncohematology, University of Milan, Milan, Italy.
Sci Rep. 2024 Sep 19;14(1):21891. doi: 10.1038/s41598-024-71719-2.
Chronic idiopathic neutropenia (CIN) is a rare benign condition caused by an immune attack against neutrophils, either primary or in the context of other autoimmune conditions, lymphoproliferative syndromes, and inborn errors of immunity. In this single-center prospective study, 131 adult CIN patients were enrolled (median age 55 years, range: 20-93). At baseline, 56% had anti-neutrophil autoantibodies and 31% had autoimmune comorbidities. Over a median 3-year follow-up, the rate of grade ≥ 2 infections was 42%, with 10% grade ≥ 3, irrespective of neutrophil counts, demographics, and anti-neutrophil antibodies positivity, and G-CSF was used in 6 patients only. No malignant evolution nor deaths were observed. Bone marrow evaluation showed a large granular lymphocyte (LGL) infiltrate in 52%, mostly polyclonal, and hypocellularity in 31% of cases. Immune-histochemistry highlighted deposits of IgG, IgM, and complement fractions C3 and C4d in most cases. Interestingly, 19% of tested patients displayed somatic mutations of myeloid genes with an association with age. In conclusion, adult CIN appears to be a benign condition without life-threatening infections, yet deserving an extensive hematologic evaluation including bone marrow assessment to inform the differential diagnosis.
慢性特发性中性粒细胞减少症（CIN）是一种罕见的良性疾病，由针对中性粒细胞的自身免疫攻击引起，可为原发性，也可继发于其他自身免疫性疾病、淋巴增生性综合征和先天性免疫缺陷。在这项单中心前瞻性研究中，共纳入了 131 例成人 CIN 患者（中位年龄 55 岁，范围：20-93 岁）。基线时，56%的患者存在抗中性粒细胞自身抗体，31%的患者存在自身免疫性合并症。中位随访 3 年后，≥2 级感染的发生率为 42%，10%为≥3 级感染，与中性粒细胞计数、人口统计学特征、抗中性粒细胞抗体阳性无关，仅 6 例患者使用了 G-CSF。未观察到恶性进展或死亡。骨髓评估显示 52%的患者存在大颗粒淋巴细胞（LGL）浸润，多为多克隆性，31%的患者存在骨髓细胞减少。免疫组化显示大多数病例中存在 IgG、IgM 和补体 C3 和 C4d 片段的沉积。有趣的是，19%的患者检测到髓系基因的体细胞突变，且与年龄相关。总之，成人 CIN 似乎是一种良性疾病，无危及生命的感染，但需要进行广泛的血液学评估，包括骨髓评估，以明确鉴别诊断。
