Background The prognosis of Henoch-Schönlein Purpura (HSP) is mainly related to renal involvement. Data on nephropathy in HSP are generally the result of analysis of selected populations seen in Nephrology Services.
Objectives In this report we assessed the frequency and outcome of nephritis in a wide and unselected series of HSP patients.
Methods Study of 142 consecutive patients classified as HSP according to the criteria proposed by Michel et al (J Rheumatol 1992; 19:721) since January 1977 to May 2012. All of them had renal involvement. Nephropathy was categorized as mild or severe. Mild nephropathy encompassed those patients with microhematuria (≥ 5 red cell/hpf) and/or proteinuria that did not reach a nephrotic syndrome range. A patient was defined as having severe nephropathy if he/she had: a) nephrotic syndrome (i.e., plasma albumin levels ≤ 25 gr/liter and either 1 gm of proteinuria/day/m2 of body surface area in children, or > 3.5 gr of proteinuria daily in adults), with or without edema; or b) acute nephritic syndrome (i.e., hematuria with at least 2 of the following abnormalities: hypertension, increased plasma urea or creatinine levels, and oliguria). Renal insufficiency was considered if the plasma creatinine was >125% of the upper limit of normal.
Results We assessed 142 HSP patients with nephritis (HSPN). At disease onset 27.4% of patients had renal involvement. During the clinical course, all of them had palpable purpura. Gastrointestinal (GI) involvement was seen in a 62% of patients. The main GI symptom was the typical colicky abdominal pain. Nausea and/or vomiting were seen in a 17.8% and melena/rectorrhagia in 32.7%. Stool guaiac test was positive in 56.8% of HSPN patients. Joint manifestations (arthralgia and/or arthritis) occurred in 61.3%. However, arthritis was only observed in 38%. Regarding nephritis, most patients had mild nephropathy. Nephrotic syndrome was found in a 12.5%, nephritic syndrome in a 6.8% and renal insufficiency in 25% of the patients. The median (IQR) amount of proteinuria (gr/24 h) was 1 (0.5-2.2) and serum creatinine (mg/dl) was 1.2 (1-2.4). Laboratory data showed leukocytosis in 22.5% and anemia in 12.7%. The mean±SD ESR was 47.1±30.2 mm/1st hour. Serum IgA levels were increased in 60% (15 of 25 tested) of patients. Corticosteroids were given to 79.6% of HSPN patients and cytotoxic drugs to 19%. After a median (IQR) follow-up of 120.8 (110-132) months complete recovery was observed in 69.7%, persistent, usually mild, hematuria in 14.8% and chronic renal insufficiency in 4.9%. During the acute phase and throughout the complete follow-up dialysis was only required in 2.9% (4/142) of patients but none of them needed kidney transplant. The disease relapsed in 38.6% of HSPN patients.
Conclusions Although renal involvement is the main prognostic factor in patients with HSP, in most cases the renal outcome is benign.
Acknowledgements This study was supported by grants from “Fondo de Investigaciones Sanitarias”PI12/00193 (Spain). This work was also partially supported by RETICS Program, RD08/0075 (RIER) from “Instituto de Salud Carlos III” (ISCIII) (Spain).
Disclosure of Interest None Declared