Clinicopathological Analysis Of Renal Involvement In Primary Sj(?)gren Syndrome

Objectives: We had retrospectively studied clinicopathological characteristics of primary Sj(?)gren Syndrome(p SS)patients with renal damage who had received renal biopsy.The Clinical,biochemical and pathological characteristics and outcome of different pathological types were compared.Clincopathological characteristics of primary Sj(?)gren syndrome with membranous nephropathy(p SS-MN)and that of Idiopathic membranous nephropathy(i MN)were compared.Methods: The clinical records of 63 p SS patients with renal damage who had received renal biopsy in The First Affiliated Hospital of Guangxi Medical University from January 2010 to October 2020 were collected.According to the pathological changes of renal under light microscopy,these patients were divided into p SS-MN group,glomerular minimal change(MCD)group,focal segmental glomerulosclerosis(FSGS)group and other pathological types group.There were19 patients in the PSS-MN group,and the clinical record of 38 i MN patients with gender and age matching the PSS-MN group in the same period were collected in a ratio of 1:2.The clinical,biochemical and pathological characteristics and outcome of these patients were compared and analyzed.Results:1.p SS patients with secondary renal damage63 p SS patients with secondary renal damage who had received renal biopsy include 56(88.89%)females and 7(11.11%)males,which makes the ratio of male to female is 1:8,suggesting that the p SS with secondary renal damage was more common in females.The average age of first visit was 50.96±13.85 years.The main clinical manifestations were dry mouth(58.7%),anemia(58.7%),facial or double leg edema(47.6%),dry eyes(41.3%),hypokalemia(34.9%),weight loss(33.3%),lymph node enlargement(22.2%),renal tubular acidosis(19.05%),etc.The 63 renal biopsy results included 19 cases of membranous nephropathy,23 cases of glomerular minimal change,10 cases of focal segmental glomerulosclerosis,3 cases of proliferative sclerosing glomerulonephritis,3cases of Ig A nephropathy(including 2 cases of focal segmental glomerulosclerosis and1 case of glomerular minimal change),1 case of mesangioproliferative glomerulone-phritis,1 case of chronic sclerosing glomerulonephritis,1 case of diffuse sclerosing glomerulonephritis,1 case of sclerosing glomerulonephritis,1case of renal interstitial and tubular injury,among which 6 cases of chronic interstitial nephritis were complicated with glomerulonephritis.Among the 63 patients,62(98.41%)had glomerular injury,40(63.49%)had renal tubular injury,38(60.32%)had renal interstitial injury,and 6(9.52%)had renal arteriole injury.The comparison among the four groups showed that: the incidence of edema in PSS-MN group was significantly higher than that in MCD group and FSGS group.The differences of serum albumin,urea nitrogen,creatinine,uric acid,cystatin C,glomerular filtration rate,potassium,total cholesterol and low density lipoprotein were statistically significant.Albumin: p SS-MN group was lower than FSGS group and other pathological types group.Urea nitrogen:MCD group was lower than FSGS group and other pathological types group,p SS-MN group was significantly lower than other pathological types group.Creatinine: p SS-MN group and MCD group were significantly lower than FSGS group and other pathological types group.Uric acid: the other pathological types were higher than those of p SS-MN and MCD group.Cystatin C: p SS-MN group was lower than FSGS group and other pathological types group,and MCD group was significantly lower than other pathological types group.The glomerular filtration rate: p SS-MN group and MCD group were higher than FSGS group and other pathological groups.Serum potassium: MCD group and p SS-MN group were lower than other pathological types group.Total cholesterol: p SS-MN group was higher than the other three groups.Low density lipoprotein: p SS-MN group was higher than MCD group and FSGS group.In terms of renal pathology,the percentage of sclerotic glomerulus was statistically different among the 4 groups.FSGS group and other pathological types group were higher than p SS-MN group and MCD group,and other pathological types group were higher than FSGS group.The deposition of immunoglobulin G(Ig G),immunoglobulin M(Ig M),complement C3 were statistically different among the four groups.The deposition of Ig G and complement C3 in p SS-MN group were significantly higher than those in the other three groups.Immunoglobulin M ’s deposition in other pathological types group was significantly higher than those in the other three groups.2.The comparison between p SS-MN and i MNThe statistics of white blood cell and lymphocyte,level of serum phosphorus,total cholesterol and high density lipoprotein in p SS-MN group were significantly lower than that in i MN group,and the level of high-sensitivity C-reactive protein,immunoglobulin A and immunoglobulin G were significantly higher than that in i MN group.In terms of renal pathology,the percentage of sclerosis glomerulus,tubular infiltration of renal tubulin,lymphocyte and plasma cell interstitial infiltration and incidence of renal sclerosis of small vessels in p SS-MN group were higher than that in IMN group.The expression of PLA2 R in renal tissue of p SS-MN group was significantly lower than that of i MN group.There was no significant difference in all-cause mortality and renal survival time between the two groups.Conclusions:1.Secondary glomerular damage of p SS is not uncommon,and its pathological types are diverse,clinical characteristics vary among different pathological types.2.No significant renal function decline occurred in p SS-MN and MCD,while renal function impairment was significant in FSGS and other pathological types.3.Inflammatory cell infiltration of kidney in p SS-MN was more common than i MN.The expression of PLA2 R in renal tissue was significantly lower than IMN.There were no significant differences in proteinuria,renal function and prognosis between p SS-MN and i MN.