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ABSTRACT: Intrarenal B cell infiltrates resembling secondary lymphoid tissue have been found in several forms of inflammatory kidney disease. Their role in renal inflammation is not well defined, perhaps because B cell clusters have been regarded as a single entity while being quite heterogeneous. Therefore we characterized intrarenal lymphoid clusters of 32 patients diagnosed with lupus nephritis and 16 with ANCA associated nephritis. We identified four increasingly organized levels of intrarenal aggregates from scattered B cells to highly compartmentalized B cell clusters with central follicular dendritic cell networks. Most B cells displayed a mature non-antibody producing phenotype with antigen presenting ability. In regions of B cell infiltration, expression of the lymphoid chemokine BCA-1 was found in cells of a dendritic-like morphology and most B cells expressed the corresponding receptor CXCR5. Biopsies containing B cells had significantly higher levels of BCA-1 mRNA expression compared to those without, suggesting a role of BCA-1 and CXCR5 for B cell infiltration into the kidney. Our study proposes a new classification of B cell clusters in lupus and ANCA associated nephritis which might help to study the function of intrarenal B cell clusters in a more differentiated manner.
Kidney International 07/2008; 74(4):448-57. · 6.61 Impact Factor
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ABSTRACT: Recent studies showed a crucial role for B cells in acute renal allograft rejection. It remains largely unknown, however, which mechanisms lead to the B-cell recruitment into the allograft. The chemokine CXCL13 and its corresponding receptor CXCR5 play a central role in B-cell trafficking to secondary lymphatic tissue and ectopic B-cell clusters in rheumatoid arthritis. We therefore investigated the potential role of CXCL13 and CXCR5 in formation of B-cell clusters in renal transplant rejection.
Serial immunohistochemical staining for CXCL13, CXCR5, and CD20 was carried out in protocol biopsies of 23 patients obtained between day 4 and day 9 after renal transplantation. Intragraft mRNA expression of CXCL13 was assessed by real-time polymerase chain reaction (PCR) analysis.
Of 23 kidney biopsies obtained between days 4 and 9 after renal transplantation, 13 revealed an acute rejection. Four of these patients showed a substantial infiltration of the transplant with cluster-forming B cells. By immunohistochemistry CXCL13 and the corresponding receptor CXCR5 were exclusively detected in areas of B-cell clusters. Intrarenal CXCL13 mRNA expression was 27-fold higher in transplants with B-cell clusters compared to rejecting allografts without B-cell accumulation (P= 0.011).
We describe a striking colocalization of CXCL13 expression with CXCR5- and CD20-positive B cells in renal transplants undergoing rejection. This is the first study demonstrating a potential role of CXCL13 and its specific receptor CXCR5 in recruitment of B cells in renal allograft rejection.
Kidney International 05/2005; 67(4):1616-21. · 6.61 Impact Factor
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ABSTRACT: Microscopic work with single-slot grids requires high-quality support films to span the relatively large gap. The imminent unavailability of the polyvinyl formal Pioloform FN 65, which to date has been used as the standard polyvinyl formal for the generation of support films in transmission electron microscopy (TEM), has necessitated the finding of a substitute material to produce such films. Therefore, we compared the polyvinyl butyral Pioloform BM 18 with the polyvinyl formal Pioloform FN 65 for the production of TEM support films, using operational criteria for assessment. Pioloform BM 18 with the solvent chloroform resulted in support films of unacceptable quality compared with Pioloform FN 65. Adding the softener dibutyl phthalate to the chloroform solvent for Pioloform BM 18 markedly improved the film quality, resulting in support films with high transparency and flexibility, and even greater stability in the electron beam when compared with films of Pioloform FN 65. Pioloform FN 65 also had the disadvantage of requiring highly toxic 1,2-dichloroethane as a solvent, whereas Pioloform BM 18 can be used with chloroform.
Journal of Electron Microscopy 02/2003; 52(3):355-7. · 1.31 Impact Factor
