Protocol biopsy of a transplanted kidney as a tool for monitoring adequacy of immunosuppressive therapy: 10 years of experience from a single transplant center.

BACKGROUND: The aims of this prospective study were to determine the prevalence of clinically silent rejection changes and of nephrotoxicity of calcineurin inhibitors among repeated protocol biopsies of transplanted kidneys and to assess their impacts on chronic graft function and damage at the end of 1 year. METHODS: We performed 424 protocol biopsies among 158 patients over the first year after transplantation. We monitored parameters of graft function and progression of chronic changes among subjects with clinically silent rejection or toxicity for comparison with a control cohort showing normal histological findings. The results of statistical tests were considered to be significant at a level of P < .05. RESULTS: At 3 weeks, 3 months, and 12 months, there were normal histological findings among 30 (19%), 21 (14.8%), and 14 (11.3%) patients, respectively; subclinical rejection changes occurred in 49 (31%), 36 (25.4%), and 20 (16.2%) grafts, respectively. At the third week, histological signs of toxicity occurred in 33 (20.9%) patients with significant persistence despite reductions in calcineurin inhibitor doses. At the end of 1 year of follow-up, both subclinical and toxic changes produced similar increases in chronic changes as quantified by the Banff score and were significantly different from the control group (P < .05). Serum creatinine concentrations and glomerular filtration rates did not accurately reflect the degree of graft damage in the early posttransplantation period. CONCLUSIONS: Subclinical rejection and toxic changes among a significant proportion of grafts are associated with progression of chronic changes already over the first year following transplantation. Hence they represent independent risk factors for the development of irreversible graft damage. Protocol biopsy seems to be an important method to monitor immunosuppressive therapy.

[Merkel cell skin carcinoma]. / Kozní karcinom z Merkelových bunek.

Merkel cell carcinoma is a rare tumour of the skin. It affects predominantly elderly Caucasian males on sun-exposed areas of the skin. Distinctively more frequent and at significantly lower age, its incidence is higher in immunocompromised patients. In these patients we often observe the highly aggressive course of Merkel cell carcinoma and a fatal outcome. The incidence of Merkel cell carcinoma has been rising in recent years and is more dramatic than the increased incidence of cutaneous melanoma. More than one-third of Merkel cell carcinoma patients will die from this cancer, making it twice as lethal as melanoma. The malignant transformation of Merkel cells is currently thought to be related to an infection with Merkel cell polyomavirus. In the early stage the discreet clinical picture may be contrary to extensive microscopic invasion and this seemingly benign appearance can delay diagnosis or increase the risk of insufficient tumour excision. The diagnosis is definitely confirmed by histological evaluation and immunohistochemical tests. A typical feature is the tendency of Merkel cell carcinoma to frequent local recurrence and early metastasizing into regional lymph nodes with subsequent tumour generalization. The mainstay of therapy is radical excision of the tumour and adjuvant radiotherapy targeted at the site of primary incidence and local draining lymph nodes. The efficacy of different chemotherapy protocols in Merkel cell carcinoma is limited and the median survival rate is measured in months. In the future, prophylaxis with vaccination against Merkel cell polyomavirus will hopefully be possible in high-risk patients, as well as therapeutic usage of antisense oligonucleotides or microRNAs, eventually complete Merkel cell carcinoma elimination by affecting the tumour suppressor gene Atonal homolog 1 expression. The staging of the tumour at time of diagnosis is the most important prognostic factor. In this respect, the importance of preventative skin inspection in high-risk immunocompromised patients must be stressed and suitable therapy must be indicated in suspected lesions.

High mobility group box-1 (HMGB-1) in osteoarthritic cartilage.

OBJECTIVES: Nucleosomal high mobility group box-1 (HMGB-1) is translocated and released from necrotic and activated cells as an endogenous danger signal (alarmin) and cytokine. It was hypothesised that it plays a role in osteoarthritis (OA). characterised by cellular activation, inflammation and enchondral bone formation. METHODS: Bovine knee joint samples, collected from culled animals, were scored using histologic/histochemical grading to intact looking, mild, moderate or severe and immunohistochemically stained for HMGB-1. Chondrocyte pellets, produced from human bone marrow-derived mesenchymal stem cells and stimulated with tumour necrosis factor-a (TNF-alpha), were similarly stained. RESULTS: In healthy looking OA cartilage chondrocyte nuclei were usually HMGB-1 negative and in mild OA staining was restricted to nuclei. In moderate OA lesions HMGB-1 was also seen in the cytoplasm and occasionally pericellular matrix and in severe OA lesions often also in intra- and inter-territorial matrix. The tidemark in healthy cartilage did not contain HMGB-1, which however was seen at this interface as linear deposits even in intact-looking and mild OA lesions, as multiple wave-like deposits in moderate and as heavy granular deposits in severe lesions. TNF-alpha stimulation of chondrocytes caused translocation of HMGB-1 from the nucleus to the cytoplasm. CONCLUSIONS: In resting chondrocytes tight nucleosomal HMGB-1 binding might cause steric hindrance of immunostaining. TNF-alpha- or OA-mediated activation leads to nuclear staining and cytoplasmic translocation. Advancing OA leads to increasingly intense extra-/pericellular deposition of HMGB-1 alarmin, indicating local chondrocyte activation and/or necrosis. In particular, HMGB-1 at the tidemark might play a role in the pathological thickening of subchondral bone plate/osteophyte formation.

Expression of nucleic acid binding Toll-like receptors in control, lupus and transplanted kidneys--a preliminary pilot study.

We hypothesized that nucleic acids, free and/or complexed, filtered and/or locally released, might be entrapped in the kidneys because of the specific nucleic acid binding microbial pattern recognizing Toll-like receptors (TLRs). This hypothesis of nucleic acid binding potential was tested using paraffin sections from healthy control, SLE and transplant kidneys, which were labelled using TLR-specific rabbit or goat anti-human antibodies in immunoperoxidase staining. Normal and transplant kidneys contain some double- (TLR-3) and single-stranded RNA binding (TLR-8) receptors, but in particular double-stranded RNA binding receptor TLR-7, mostly in tubuli, whereas no DNA binding TLR-9 was found. SLE kidneys contain more TLR-3 and TLR-8 and express de novo also TLR-9, in particular in glomeruli. On the contrary, TLR-7 was relatively weak in SLE. It is concluded that kidneys have a capacity to bind nucleic acids. TLR stimulation leads to the production of tumour necrosis factor-alpha and other pro-inflammatory cytokines and to up-regulation of co-stimulatory molecules necessary for the adaptive immune response. This makes renal tissues a potential target for inflammatory and immune responses in autoimmune disease and in the reaction for the foreign tissue.

C1q complement component and -antibodies reflect SLE activity and kidney involvement.

The role of the complement system in the pathogenesis of systemic diseases is very ambivalent. In systemic lupus erythematosus (SLE), many abnormalities in the activation of the complement system have been reported. The most important antibodies formed against the complement system in SLE are the ones associated with the C1q component. The aim of this study was to assess separately the anti-C1q antibodies and C1q component in the serum from 65 patients with SLE, then in individuals with (n=33) and without (n=32) lupus nephritis and with active (n=36) and nonactive (n=29) form of the disease (European Consensus Lupus Activity Measurement, ECLAM>3, ECLAM

[Neopterin and a soluble interleukin-2 receptor in patients with systemic lupus erythematodes]. / Neopterin a solubilní receptor interleukinu-2 u nemocných se systémovým lupus erythematodes.

Goal of this study was to monitor levels of serum neopterin and soluble interleukin-2 receptor (sIL-2r) and to evaluate their importance in monitoring activity of systemic lupus erythematodes (SLE). Levels of serum neopterin, anti-dsDNA antibodies, C3, C4 complement components, nucleosomes antibodies, IL-10, fas ligand, soluble thrombomodulin, sVCAM-1, and sICAM-1 were measured in a group of 52 patients with SLE. Positive correlations were proved between neopterin concentrations and disease activity (ECLAM), levels of sVCAM-1, sICAM-1, sIL-2r and thrombomodulin, further between sIL-2r level and disease activity (ECLAM), and concentrations sVCAM-1, sICAM-1 and neopterin. Higher values of neopterin and sIL-2r levels were identified in patients with lupus nephritis compared to patients without kidney impairment. Statistically significant differences were identified in levels of neopterin between a subgroup (A) with minimum disease activity and a subgroup (B) with increasing disease activity (p = 0.01) and a subgroup (C) with decreasing disease activity (p = 0.003 ) and a subgroup (LN) with lupus nephritis (0.007) during the first and the third series of measurements. sIL2r levels which had in all subgroups very varied values were the lowest in the subgroup A with minimum disease activity during the whole time of monitoring. The highest levels reached the free receptor IL-2 in the subgroup B with increasing disease activity and in the subgroup with lupus nephritis. Statistically significant differences in values were identified between the subgroup A (non-active) and the subgroup LN (lupus nephritis) with p = 0.01 during the first set of the measurements. Fluctuation of sIL-2r levels in individual subgroups during the time of monitoring did not reach statistically important levels. In conclusion it could be said that potential practical utilization of the measurement of concentrations of the two mentioned molecules should be seen especially in monitoring disease activity because they don't contribute to SLE with needed information. Their always low values have favourable prognostic impact in monitoring patients with SLE and vise versa.