Streptococcal Infection In Childhood Henoch-sch(?)nlein Purpura:a 5-year Retrospective Study

Objective The present study focuses on the associations of streptococcal infection with the clinical manifestations,relapse/recurrence and renal involvement in Henoch-Sch(?)nlein purpura(HSP)children.MethodsThis study retrospectively collected the medical records of 2238 children with HSP between January 2015 and December 2019 in our hospital,excluded 164 cases and included 2074 cases.Patients’ histories associated with HSP onset(vaccination history,allergy history,insect bite history,etc.)were obtained by interviews and medical history collection.The specimens of blood and urine were collected,and enzyme-linked immunoassay and immunoturbidimetric assay were applied to screen for possible etiology.Antistreptolysin O titer was measured using nephelometry in the acute and convalescent stage.Children with HSP were divided into streptococcal infectious group,the other infectious group and the non-infectious group according to the inducement and infection type.42 cases with HSP nephritis(HSPN)were subjected to renal biopsy.The specimens were stained with hematoxylin and eosin,periodic Acid-schiff,and Schiffmethenamine silver and examined by light microscopy.Renal biopsy specimens were graded based on the established International Study for Kidneys Disease in Children(ISKDC)classification.Results(1)Series of potential infections were identified in 49.66% of 2074 HSP children.Based on the laboratory results,there were 393 cases(18.95%)with streptococcal infection,87cases(4.19%)with helicobacter pylori infection,84 cases(4.05%)with mycoplasma infection,10 cases(0.48%)with parainfluenza infection,4 cases(0.19%)with tubercle bacillus infection,3 cases(0.14%)with respiratory syncytial virus infection and 2 cases(0.10%)with toxoplasma gondii infection.(2)Among the 393 cases with streptococcal infection,43.00% of them had arthritis/arthralgia,32.06% had abdominal pain and 29.26% had renal involvement.(3)After treatment,the relapse/recurrence rate of streptococcal infectious group was19.34%(76/393),that of the other infectious group was 20.41%(130/637),and that of the non-infectious group was 32.09%(335/1044).Significant difference in the relapse/recurrence was found among the three groups.(4)The biopsy findings according to the ISKDC were as follows: class II: 40.48%;IIIa:23.81%;IIIb: 35.71%.By immunofluorescence,the hallmark of HSPN consisted of diffuse mesangial deposition of Ig A,and to some extent,co-deposition of kappa(78.57%)and lambda(76.19%).No significant differences in the ISKDC classification and immune complex deposits existed among the three groups.Conclusions(1)Streptococcal infection is the most frequent infectious trigger for childhood HSP.(2)Besides purpura,arthritis/arthralgia was the most common clinical manifestation in these cases having streptococcal infection;different sources of infection did not affect the clinical presentation of children with HSP.(3)The possible elimination of streptococcal infection reduces the risk of HSP relapse/recurrence compared to children with non-infectious causes.(4)Streptococcal infection does not aggravate renal pathological damage in children with HSP.