ABSTRACT
Objective:To observe the clinical features in Gitelman syndrome (GS) patients with different urinary calcium excretion, and investigate the value of urinary calcium excretion in the clinical classification for GS.Methods:GS cases from the National Rare Diseases Registry System of China (NRSC) (2016-2018) with SLC12A3 gene screened in Peking Union Medical College Hospital were collected. The features of urinary calcium excretion were analyzed, and the phenotypes of patients with hypocalciuria were compared to those without. Hydrochlorothiazide (HCT) test was performed according to the standard process, and the maximal increment of chloride excretion fraction (ΔFECl) was calculated. Results:A total of 83 GS patients were included, among whom 53 (63.86%) patients had hypocalciuria. The ratio of urinary calcium/creatine was significantly lower in patients with hypocalciuria compared to those without [(0.085±0.058) mmol/mmol vs (0.471±0.284) mmol/mmol, t=7.349, P<0.001]. Age, gender, estimated glomerular filtration rate, blood pressure, serum and urinary electrolytes, and alkalosis were all comparable between groups. Fatigue ( χ2=4.595, P=0.032) and polyuria ( χ2=5.778, P=0.016) were less frequently reported in hypocalciuria patients, while all the other clinical symptoms were comparable. Sixteen patients in each group underwent HCT test, and the median value of ΔFECl was comparable between patients with and without hypocalciuria [0.539%(0.430%, 1.283%) vs 0.829% (0.119%,1.298%), U=130.000, P=0.956], both of which indicated no response to HCT. Conclusions:The proportion of low urinary calcium in GS patients is 63.86%. There is no definite relationship between urinary calcium excretion, phenotype and the extent of NCC dysfunction.
ABSTRACT
Osteoporosis is a global public health problem. The kidney, especially the Na-Cl co-trans-porter ( NCC) located in the renal distal tubular cells, which is an important transporter for urinary calcium reg-ulation, plays an important role in calcium homeostasis and bone metabolism. This review summarized recent re-searches on effects and mechanisms of NCC on calcium and bone metabolism.
ABSTRACT
Objective To explore the initial symptoms of synovitis,acne,pustulosis,hyperostosis,osteitis (SAPHO) syndrome,and to analyze the clinical and laboratory characteristics of these patients.Methods We retrospectively analyzed the initial symptoms of 164 patients diagnosed with SAPHO syndrome presented at Peking Union Medical College Hospital from 2004 to 2015,and their clinical,laboratory,and radiological data were collected.The t test,Mann-Whitney U test and chi-square test were used to compare the clinical differences between the SAPHO patients with different initial symptoms.Results Among the 164 patients recruited,84(51.2％) had skin lesions before osteoarticular symptoms,whereas 29(17.7％) after and 42(25.6％) simultaneously.Nine (5.5％) patients had no skin lesions.The time interval between onset of skin and osteoarticular lesions was less than 2 years in 133 (81.1％) patients,but up to 35 years at most.Interestingly,a significantly higher age at onset was observed in patients with osteoarticular symptoms prior to skin lesions than those after [(41 ±10) years vs (36±11) years,t=-2.174,P=0.032].Moreover,positive HLA-B27 was more frequently detected in patients having osteoarticular symptoms as the initial presentations (10.3％ vs 0,P=0.016).Although treated more aggressively before baseline,patients presented with osteoarticular symptoms prior to skin lesions had significantly higher level of hs-CRP at baseline compared with those after [5.42 (1.88,12.70) mg/L vs 11.60 (3.76,22.08) mg/L,Z=-2.096,P=0.036].Conclusion Skin lesions tend to appear prior to osteoarticular symptoms in most SAPHO syndrome patients.The percentage of patients who developed skin lesions after osteoarticular symptoms increase with age at onset.