Objective To establish a flow cytometric measurement of detecting minimal residual disease(MRD) according to the leukemia-associated immunophenotypes in children with acute lymphoblastic leukemia(ALL) and to explore the significance of MRD detection in ALL children for a individualized treatment. Methods A variety of four-color fluorescent antibody combinations were used to investigate the children's normal bone marrow. The normal bone marrow pattern at two-parameter plots was established to identify the residual tumor cells, seventy-five bone marrow samples from newly diagnosed ALL children were analyzed with four-color cytometry to determined the optimal combinations which can clearly distinguish the tumor cells from normal cells. The bone marrow samples were monitored with the combination panel in 60 patients at the end of induction therapy and follow-up treatment. Cytomorphology test, PCR amplification of 29 fusion genes as well as IgG and TCR gene rearrangements were performed simultaneously. Results Sixty-nine cases (92.0%) could be identified for effective antibody combinations to monitor MRD by four-color cytometry. Fusion genes or IgG and T cell receptor (TCR) gene rearrangements can be detected in 21 cases (28.0%) to monitor MRD by PCR. No MRD can be detected in 25 bone marrow samples at the end of induction therapy and follow-up treatment. Four-color cytometry could detect as low as 0.021%-4.130% residual leukemia cells. Conclusion MRD can be monitored by flow cytometry which is faster than PCR, and the sensitivity is superior to morphology method.

Objective:To investigate clinical and histopathological features of adult erythema nodosum (EN) .Methods:Clinical data were collected from 54 adult inpatients with histopathologically confirmed EN in Department of Dermatology and Venereology, the First Affiliated Hospital of Wannan Medical College from November 2019 to July 2022, and analyzed retrospectively.Results:Among the 54 EN patients, there were 6 males and 48 females, their ages were 42.50 ± 11.68 years (range, 18 - 73 years), and their disease course ranged from 1 day to 10 years; 30 patients (55.56%) were diagnosed with idiopathic EN, and 24 (44.44%) with secondary EN. The most common etiological factor in secondary EN was infection (17 cases), including respiratory tract infection (9 cases), tuberculosis infection (6 cases), upper respiratory tract infection comorbid with active hepatitis B virus infection (2 cases) ; the following common etiological factor was connective tissue disease (7 cases), including Behcet′s syndrome (4 cases), Sj?gren′s syndrome (1 case), and undifferentiated connective tissue diseases (2 cases). The patients′ ages were significantly younger in the secondary EN group (38.33 ± 12.15 years) than in the idiopathic EN group (46.17 ± 10.20 years, t = 2.58, P = 0.013). All patients had skin lesions on their lower limbs, lesions were limited to both lower limbs in 24 patients with idiopathic EN and 12 with secondary EN, and the proportion of patients with lesions limited to both lower limbs was significantly lower in the secondary EN group than in the idiopathic EN group ( χ2 = 5.44, P = 0.020). Compared with the idiopathic EN group, the secondary EN group showed significantly increased white blood cell counts ([7.56 ± 2.46] × 10 9/L vs. [6.04 ± 1.60] × 10 9/L, t = 2.62, P < 0.05) and C-reaction protein levels (34.34 ± 46.48 mg/L vs. 11.45 ± 18.13 mg/L, t = 2.28, P < 0.05). In the idiopathic EN group, 23 patients mainly showed histopathological features of septal panniculitis, while 17 patients in the secondary EN group mainly showed histopathological features of mixed panniculitis or lobular panniculitis, and the proportion of patients with histopathological features of mixed panniculitis or lobular panniculitis was significantly higher in the secondary EN group than in the idiopathic EN group ( χ2 = 12.18, P < 0.001) . Conclusion:EN was more common in female adults; idiopathic EN was the most common type, and secondary EN may be a cutaneous sign of systemic diseases; for EN patients at a relatively young age, with lesions involving both lower limbs or more sites, higher white blood cell counts and C-reaction protein levels, and histopathological manifestations of lobular panniculitis, systemic examinations were required to rule out underlying causes.