CD44-negative parietal–epithelial cell staining in minimal change disease: association with clinical features, response to corticosteroids and kidney outcome

Background

Activation of parietal–epithelial cells (PECs) with neo-expression of CD44 has been found to play a relevant role in the development of focal and segmental glomerulosclerosis (FSGS). The aim of this study was to analyse whether the expression of CD44 by PECs in biopsies of minimal change disease (MCD) is associated with the response to corticosteroids, with kidney outcomes and/or can be considered an early sign of FSGS.

Methods

This multicentric, retrospective study included paediatric and adult patients with MCD. Demographic, clinical and biochemical data were recorded, and biopsies were stained with anti-CD44 antibodies. The association between PECs, CD44 expression and the response to corticosteroids, and kidney outcomes were analysed using logistic, Kaplan–Meier and Cox regression analyses.

Results

A total of 54 patients were included: 35 (65%) <18 years and 19 (35%) adults. Mean follow-up was 68.3 ± 37.9 months. A total of 19/54 patients (35.2%) showed CD44-positive staining. CD44-positive patients were younger (14.5 ± 5 versus 21.5 ± 13, P = 0.006), and showed a higher incidence of steroid-resistance [11/19 (57.8%) versus 7/35 (20%), P = 0.021; odds ratio: 5.5 (95% confidence interval 1.6–18), P = 0.007] and chronic kidney disease [9/19 (47.3%) versus 6/35 (17.1%), P = 0.021; relative risk: 3.01 (95% confidence interval 1.07–8.5), P = 0.037]. Follow-up re-biopsies of native kidneys (n = 18), identified FSGS lesions in 10/12 (83.3%) of first-biopsy CD44-positive patients versus 1/6 (16.7%) of first-biopsy CD44-negative patients (P = 0.026).

Conclusions

In patients with a light microscopy pattern of MCD, CD44-positive staining of PECs is associated with a higher prevalence of steroid resistance and worse kidney outcomes, and can be considered an early sign of FSGS.

Seasonal variations in the onset of positive and negative renal ANCA-associated vasculitis in Spain

Background

The closure of long-standing gaps in our knowledge of aetiological factors behind anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a major challenge. Descriptive and analytical epidemiological studies can improve our understanding of environmental influences. Reported seasonal variations in AAV, mainly related to Wegener's disease, have shown an increasing number of cases in the winter months, which could be related to an extrinsic factor underlying infection. The objective of this paper was to study seasonal variations in AAV with respect to renal affectation diagnosed in Catalonia, Spain.

Methods

Two hundred and thirty-four patients diagnosed for renal AAV between 2001 and 2014 in eight hospitals in Catalonia were included in the study. We used medical records to retrospectively analyse the date of the first symptoms attributed to the AAV, ANCA subtypes, the degree of renal impairment and renal histology.

Results

Of the 234 patients studied, 49.2% were male and 50.8% female. For ANCA status, 8.5% were positive, 15.9% were proteinase-3-positive and 75.6% were myeloperoxidase-positive. In relation to histological classification, 17.8% were sclerotic, 11.7% focal, 38.8% crescentic and 31.7% mixed. Regarding seasonal distribution, we observed a clear seasonal periodicity with a significantly higher incidence of cases in the winter. Applying an Eigen decomposition, we observed a periodic fluctuation of frequencies around the annual cycle with peaks every 10-12 months, and higher incidence of AAV cases in February.

Conclusions

Our results confirm, in Catalonia, the seasonal periodicity of AAV with a higher incidence in the winter, as formerly described in the literature for other regions. An environmental factor, likely one that is infectious, may explain this finding.

SU-E-I-32: Sterile Radiation Reduction Gloves May Be Contraindicated in Fluoroscopically Guided Interventions

PURPOSE

Sterile radiation reduction gloves have been widely used in the past decade to provide modest decreases in operator hand dose when the hands are placed in the field of view (FOV). While multiple publications have quantified the potential dose reduction from the use of such gloves, possible effects on the patient have not yet been assessed. The aim of this study was to determine if radiation reduction gloves can Result in a significant increase in patient dose and increased risk of radiation induced skin injury when used in interventional radiology.

METHODS

The effect of radiation reduction gloves when used in the FOV was determined by measurement of patient entrance exposure rate (EER) for a variety of patient sizes and varying operating and magnification modes. EERs were measured with no glove in the FOV, with one glove and, to replicate the actions of many dose-conscious radiologists, with double gloves in the FOV.

RESULTS

Compared to an ungloved hand, the use of a single radiation reduction glove near the center of the FOV results in a 2-fold average increase in patient EER. The use of double radiation reduction gloves results in a 3-fold average increase in EER. In both cases, this increase was only weakly dependent on the size of the patient and on the operating and magnification modes used. In fact, patient thicknesses ranging from 6-14 inches and operating modes ranging from low-dose fluoroscopy to DSA produced less than a 20% deviation from the increases in EER quoted above.

CONCLUSIONS

When used in the FOV, radiation reduction gloves can substantially increase patient EER. This increase in patient dose, when compared with the relatively small published reduction in extremity dose provided to the operator, may make their use contraindicated in cases where radiation induced skin injury is a possible risk.