[Clinical characteristics and related factors analysis of adrenal crisis occurred in children with primary nephrotic syndrome]

Objective: To investigate the clinical characteristics and related factors of corticosteroid induced adrenal crisis (AC) in children with primary nephrotic syndrome (NS). Methods: Case control study. The case group included 7 children aged 1 to 18 years with NS combined with AC hospitalized in Peking University First Hospital from January 2016 to May 2021 (AC group). According to the ratio of case group: control group 1: 4, 28 children aged 1 to 18 years who were diagnosed with NS without AC during the same period were matched as controls (non-AC group). Clinical data were collected. The clinical characteristics of AC were described. The clinical parameters were compared between the 2 groups by t test, Mann-Whitney U test or Fisher's test. Receiver operating characteristic (ROC) curve was used to analyze the cutoff values of clinical parameters for prediction of AC. Results: The AC group included 4 boys and 3 girls aged 6.9 (4.6, 10.8) years. The non-AC group included 20 boys and 8 girls aged 5.2 (3.3, 8.4) years. All AC events occurred during the relapse of NS with infection. Seven children had gastrointestinal symptoms such as nausea, vomiting and abdominal pain. Six children had poor mental state or impaired consciousness. No significant differences in NS course, corticosteroid treatment course, corticosteroid type, steroid dosage, steroid medication interval, the proportion of gastroenteritis and fever existed between the two groups (all P>0.05). Compared with the non-AC group, the duration from the onset of the relapse of NS until hospitalization in the AC group was significantly shorter (0.2 (0.1, 0.6) vs. 1.0 (0.4, 5.0) month,U=25.50, P=0.005). The 24 h urinary total protein (UTP) level was significantly higher in the AC group (193 (135, 429) vs. 81 (17, 200) mg/kg, U=27.00,P=0.036) than the non-AC group. The serum albumin level in the AC group was significantly lower((13.1±2.1) vs. (24.5±8.7) g/L,t=-6.22,P<0.001) than the non-AC group. There were significantly higher total white blood cell counts ((26±9)×109 vs. (11±5)×109/L,t=4.26,P=0.004), percentage of neutrophils (0.71±0.08 vs. 0.60±0.19,t=2.56,P=0.017) and the proportion of children with C reactive protein level≥8 mg/L (3/7 vs. 0,P=0.005) in the AC group than in the non-AC group. ROC curve analysis showed that the cutoff value of 24 h UTP was 122 mg/(kg·d) with a sensitivity of 100.0% and specificity of 70.4%. The cutoff value of serum albumin was 17.0 g/L with a sensitivity of 100.0% and specificity of 82.1%. Conclusions: Gastrointestinal symptoms and poor mental state were prominent manifestations of AC in children with NS. High 24 h UTP level, low serum albumin level, high peripheral white blood cell counts, high neutrophils percentage, and high C-reactive protein level during the early stage of NS relapse may be related to the occurrence of AC in children with NS.

[Suitability of estimated urine protein using different estimated 24 h urine creatinine equations in children with glomerular diseases]

Objective: To assess the reliability of estimated urine protein to predict 24 h urine protein excretion in children with glomerular diseases. Methods: Four hundred and forty-three children with glomerular diseases, who were admitted to pediatric department of Peking University First Hospital from January 2001 to December 2021, were enrolled in the cross-sectional study. The 24 h estimated urine creatinine which calculated by 6 previously described equations, 24 h measured urine creatinine, measured urine protein-to-creatinine ratio(UPCR), 24 h urine protein (24 hUP) and urinary sediment analysis with microscopy were collected, estimated urine protein was computed as the product of measured UPCR and estimated or measured 24 h urine creatinine. Spearman correlation analysis, Bland-Altman analysis and linear regression analysis were used to compare the correlation, agreement and accuracy between estimated urine protein and 24 hUP, and the effect of urinary protein level and erythrocyte numbers on their relationship was analyzed. Results: Of 443 children with glomerular diseases (aged (11±4) years, 221 male, 222 female), there were 216 participants with nephrotic syndrome, 78 participants with IgA nephropathy, 47 participants with Alport syndrome, 42 participants with lupus nephritis, 58 participants with purpura nephropathy, and 2 participants with isolated proteinuria. Spearman correlation analysis showed a strong correlation between estimated urine protein and 24 hUP (r=0.90, P<0.05), and the correlation improved after multiplying the measured UPCR by 24 h measured urine creatinine (r=0.94, P<0.05). Improved correlation was also observed using the estimated urine creatinine which calculated by Hellerstein formula, Ghazali-Barratt formula, Ellam formula, Walser formula, Cockcroft-Gault formula, Ix formula (r=0.93, 0.94, 0.90, 0.90, 0.94, 0.93, all P<0.05).Bland-altman analysis showed that the difference between measured UPCR and 24 hUP was (-0.30±2.22) g, consistency limit was -4.65-4.04, and the consistency improved after 24 h measured urine creatinine correction (difference was (0.27±1.31) g, consistency limit -2.30-2.84). The consistency of estimated urine protein was further improved after correction by different formulas, and the Cockcroft-Gault formula showed the best consistency between estimated urine protein and 24 hUP (difference was (0.11±1.18)g, consistency limit was -2.20-2.42). Linear regression analysis showed that measured UPCR had poor accuracy in predicting 24 hUP (R²=0.55, α=0.48, β=0.60, P<0.05), and the accuracy improved after 24 h measured urine creatinine correction, the accuracy of estimated urine protein for predicting 24 hUP was further improved by using different formulas, and Cockcroft-Gault formula was the best (R²=0.81, α=0.18, β=0.96, P<0.05). With the increase of urinary protein level and the decrease of urinary erythrocyte numbers, the correlation, agreement and accuracy between estimated urine protein and measured UPCR and 24 hUP were improved(all P<0.05). Except Ellam and Ix formulas, estimated urine protein using the rest four formulas outperformed measured UPCR(all P<0.05). Conclusion: The 24 h urine creatinine excretion rate (obtained by the Cockcroft-Gault equation)-weighted urine protein-to-creatinine ratio more reliably predicts 24 hUP than measured UPCR alone in children with glomerular diseases.

[C1q or IgA deposition in glomeruli of children with primary membranous nephropathy]

Objective: To assess the correlation of glomerular C1q or IgA deposition with clinical and pathological features of primary membranous nephropathy (PMN) in children. Methods: The clinical and pathological manifestations including (phospholipase A2 receptor, PLA2R) and IgG subclasses staining in renal biopsies, serum anti-PLA2R antibody and therapeutic response of 33 children diagnosed with PMN in Peking University First Hospital from December 2012 to December 2020 were retrospectively summarized and analyzed. According to results of PLA2R test and findings renal pathological, the patients were divided into PLA2R-related group and non-PLA2R-related group, typical MN group and atypical MN group, C1q deposit group and non-C1q deposit group, as well as IgA deposit group and non-IgA deposit group respectively. T-test, Mann-Whitney U test and Fisher's exact probability test were used for comparison between the groups. Results: Among the 33 children with PMN, there were 20 males and 13 females, of that the age of onset was 11 (8, 13) years, and 32 patients had nephrotic level proteinuria. Renal biopsies were performed at 4.6 (2.1, 11.6) months after onset, and 28 patients (85%) received glucocorticoid or immunosuppressive therapy prior to renal biopsy. There were 20 cases (61%) with PLA2R-related MN and 13 cases (39%) with non-PLA2R-related MN. Compared with the non-PLA2R-related group, the PLA2R-related group had an older age of onset (12 (10, 13) vs. 7 (3, 12) years, Z=-2.52, P=0.011), a lower preceding infection rate (45% (9/20) vs. 11/13, P=0.032) and lower spontaneous remission rate (0 vs. 4/13, P=0.017). Renal PLA2R positivity was significantly associated with predominant or co-deposition of IgG4 (13/17 vs. 5/15, P=0.031) and low albumin levels at renal biopsy ((25±6) vs. (29±7) g/L, t=2.14, P=0.041). There were 12 patients with typical PMN and 21 patients with atypical PMN, and no significant difference in clinical and pathological manifestations was found between these 2 groups (all P>0.05). There were 10 cases (32.3%) with glomerular C1q deposition, and their disease course before renal biopsy was significantly shorter than those without C1q deposition (1.8 (0.8, 5.9) vs. 6.0 (2.5, 22.3) months, Z=-2.27, P=0.023). Twelve cases (36.4%) had glomerular IgA deposition, and their course of disease,clinical and pathological manifestations were not significantly different from those without IgA deposition (all P>0.05). Conclusion: Glomerular C1q or IgA deposition may not affect the clinical manifestations, glomerular PLA2R and IgG subclasses staining pattern, or the response to treatment of PMN in children.

[Clinical characteristics of glucocorticoid-induced eye adverse reactions in children with primary nephrotic syndrome]

OBJECTIVE

To investigate the clinical features and side effects, with regard to glucocorticoid-induced ocular hypertension, glaucoma or cataract in children with primary nephrotic syndrome.

METHODS

Clinical data were collected and analyzed from 71 cases of primary nephrotic syndrome with glucocorticoid-induced ocular hypertension, glaucoma or cataract from Jun. 2014 to Jun. 2016. These children were hospitalized in Peking University First Hospital.

RESULTS

Totally 1 580 children with primary nephrotic syndrome were collected, glucocorticoid-induced complications in eyes were found in 71 cases, and the incidence was 4.5%. There were 66 cases with ocular hypertension, 2 cases with glucocorticoid glaucoma, 2 cases with glucocorticoid glaucoma combined with cataract, 1 case with high intraocular pressure combined with cataract. There were 41 boys and 30 girls with eye-related side effects caused by glucocorticoid. The average age of onset of glucocorticoid-induced eye adverse reactions in children with primary nephrotic syndrome in our research were 8 (2, 16) years. The average duration or interval time from glucocorticoid medication use to eye adverse effects was 157 (6, 420) days. No statistical significance was found in intraocular pressure between different genders, types of glucocorticoid, different route of glucocorticoid and whether methylprednisolone pulse treatment (P>0.05). There was no significant correlation between age, body mass index, blood pressure, cumulative dosage, duration time of glucocorticoid, mean daily dosage and glucocorticoid-induced ocular hypertension (P>0.05). The ocular hypertension was controlled after treatment.

CONCLUSION

Children with nephrotic syndrome after treatment of glucocorticoid are susceptible to ocular complications, and the occurrence of ocular hypertension is closely related to glucocorticoid susceptibility of the nephrotic children. Regular eye monitor is indispensable for the children suffering from primary nephrotic syndrome.

Direct quantification of mono- and di-D-α-tocopherol polyethylene glycol 1000 succinate by high performance liquid chromatography

A simple and direct reversed-phase high performance liquid chromatography (RP-HPLC) method with UV detection was developed and validated for the determination of mono- and di-D-α-tocopherol polyethylene glycol 1000 succinate (TPGS 1000) in TPGS mixture. Before the HPLC analysis, mono- and di-TPGS 1000 were separated by simulated moving bed (SMB) chromatography system and characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The mass spectrometric results confirmed that the molar mass distribution of TPGS prepared in our laboratory was very close to that of the product of Eastman Chemical Company with similar n¯ (average polymerization degree), M(n)¯ (number-average molecular weight) and M(w)¯ (weight-average molecular weight). The HPLC analysis was carried out on a C30 analytical column with mobile phases comprised of acetonitrile (A) and isopropanol (B) in gradient conditions. Validation of the analytical method was done on the following parameters: system suitability, linearity, limits of detection and quantification, accuracy and precision, method robustness and solution stability. The linearity of the calibration curves for mono- and di-TPGS 1000 from both sources was found to be good (r(2)>0.9996). The recovery values were from 94.6% to 103.3% for mono-TPGS, and 93.5% to 103.3% for di-TPGS. This method could be successfully used in the direct quantification of mono- and di-TPGS in TPGS 1000 mixture using TPGS standards with similar molecular mass distributions although derived from different sources.