NLRP3 Localizes to the Tubular Epithelium in Human Kidney and Correlates With Outcome in IgA Nephropathy.

Nod-like receptor pyrin domain-containing-3 (NLRP3) has been implicated in the pathogenesis of experimental renal injury, yet its characterization in human kidney disease remains largely unexplored. NLRP3 expression was evaluated in human kidney biopsies, primary renal tubular cells (HPTC) and correlated to disease outcomes in patients with IgA nephropathy (IgAN). NLRP3 localized to renal tubules in normal human kidney tissue and to mitochondria within HPTC by immunohistochemistry and immunofluorescence microscopy. Compared to control kidneys, NLRP3 gene expression was increased in biopsies of patients with IgAN. While NLRP3 expression in IgAN was detected in glomeruli, it remained largely confined to the tubular epithelial compartment. In vitro NLRP3 mRNA and protein expression were transiently induced in HPTC by TGF-ß1 but subsequently diminished over time as cells lost their epithelial phenotype in a process regulated by transcription and ubiquitin-mediated degradation. Consistent with the in vitro data, low NLRP3 mRNA expression in kidney biopsies was associated with a linear trend of higher risk of composite endpoint of doubling serum creatinine and end stage renal disease in patients with IgAN. Taken together, these data show that NLRP3 is primarily a kidney tubule-expressed protein that decreases in abundance in progressive IgAN.

Clonality of the immunoglobulin heavy chain genes in B cell non-hodgkin lymphoma using semi-nested PCR.

BACKGROUND: Identification of gene rearrangements and clonality analysis are important techniques for the diagnosis of malignant lymphoproliferative diseases. These methods have various sensitivities based on the type of primer used and method of determination of polymerase chain reaction (PCR) products. This study aimed at determining the clonality of B cell non-Hodgkin lymphoma in Iranian patients using PCR method and 2 primers of FR2 and FR3. MATERIALS AND METHODS: Paraffin embedded blocks of 67 patients with B cell lymphoma and 19 cases with lymphoid hyperplasia of the lymph nodes who presented to NRITLD, Masih Daneshvari Hospital were retrospectively reviewed. After extracting the genomic DNA using phenol and chloroform, clonal analysis was performed using semi-nested PCR by using two primers: FR2 and FR3. PCR products were determined using 2 techniques of heteroduplex analysis, polyacrylamide gel and silver staining and the conventional method of agarose gel and ethidium bromide staining. Appearance of 1 or 2 bands in the desired location were considered as a sign of clonality. RESULTS: Monoclonal gene rearrangement was observed in 62 out of 67 patients (92.5%) as one or two discrete bands appeared within 60-120 base pairs (bp) and 200-300 bp range. Of the mentioned patients, 53 cases (79.1%) had FR2 and 51 (76.1%) had FR3 rearrangement. Heteroduplex analysis along with silver nitrate staining detected 3 out of the remaining 5 cases of lymphoma to be monoclonal. These cases had been reported negative by the conventional technique. In total, 65 out of 67 patients (97%) showed monoclonal gene rearrangement using both the abovementioned techniques. All hyperplasia cases were polyclonal by this method. CONCLUSION: Our study showed that evaluation and detection of clonality using PCR, FR2 and FR3 primers along with heteroduplex analysis is a rapid sensitive technique for the diagnosis of malignant lymphomas.

The diagnostic value of Ki-67 and repp86 in distinguishing between benign and malignant mesothelial proliferations.

CONTEXT: The differentiation of benign mesothelial proliferations from malignant mesotheliomas may be difficult, especially when evaluating small specimens from pleural biopsies. OBJECTIVE: To explore the potential value of 2 proliferative cell markers, Ki-67 and restrictedly expressed proliferation-associated protein 86 kDa (repp86), in distinguishing between malignant mesothelioma (MM) and benign reactive mesothelial hyperplasia (MH). DESIGN: Thirty-six cases of MM from 26 men and 10 women with a mean age of 62.9 years (range, 36-80 years) and 22 cases of benign reactive MH from 14 male and 8 female patients with a mean age of 51.5 years (range, 15- 88 years) were included in this study. The proliferative status of the lesions was assessed by immunohistochemistry using monoclonal antibodies to Ki-S2 (repp86) and Ki-S5 (Ki-67). The labeling indices were quantified. RESULTS: The mean labeling indexes for Ki-67 in MM and benign reactive MH were 24.6% (range, 1%-66%) and 6.23% (range, 0%-25%), respectively. The mean labeling indexes for repp86 in MM and benign reactive MH were 26.3% (range, 0%-50%) and 3.26% (range, 0%- 21%), respectively. The average proliferative cell count was significantly higher in MM compared with benign reactive MH (P < .001). Furthermore, both markers showed a significant correlation in their expression in MM and benign reactive MH (r = 77.5, P < .001). Sensitivities of 88% and 92% and specificities of 92% and 94% were obtained at a cutoff point of 9% for Ki-67 and repp86, respectively. CONCLUSIONS: Used in combination, Ki-67 and repp86 appear to be useful markers in differentiating MM from benign reactive MH.