The frequency of cardiac amyloidosis in 182 patients receiving carpal tunnel release surgery

Introduction

Retrospective studies have suggested that a significant proportion of patients with cardiac amyloidosis received surgical treatment for carpal tunnel syndrome (CTS) 5–10 years before diagnosis of their cardiac condition. So far, one cross-sectional study has investigated the presence of localized and systemic amyloidosis in 98 patients undergoing carpal tunnel release surgery (CTRS). Ten percent were shown to have amyloid deposits in the carpal tunnel while two had cardiac involvement caused by either AL amyloidosis or wild-type transthyretin amyloidosis (ATTR).

Purpose

To investigate the prevalence of cardiac amyloidosis among unselected and consecutive patients undergoing CTRS.

Methods

Tissue samples from the carpal tunnel of 182 CTRS patients were stained with Congo Red. Amyloid positive samples were subtyped by immunoelectron microscopy and mass spectrometry.

Amyloid positive patients underwent investigations for cardiac amyloidosis including ECG-recording, echocardiography and strain imaging, cardiac magnetic resonance imaging and whole-body scintigraphy (99m-tc-DPD). Genetic investigation of the gene for TTR was performed in patients with ATTR amyloidosis or an undetermined subtype. Patients were also investigated by measurements of NT-proBNP, troponins, immunoglobulins, M-protein in serum and urine, and free light kappa and lambda chains in serum.

Results

In total, 16% (29/182) of the patients had amyloid positive biopsies. They were significantly older than amyloid negative patients (73 years vs 53 years, p<0.001). The prevalence of males was significantly higher in the amyloid positive group (66% vs 25%, p<0.001). The presence of bilateral CTS was not associated with amyloid deposits.

The subtype of amyloid was shown to be (a) ATTR in 86% (n=25) of patients, (b) localized light-chain amyloidosis in 3% (n=1), and (c) fibrinogen alpha amyloidosis in 3% (n=1), while the amount of tissue did not allow subtyping in 7% (n=2). All ATTR patients had a normal genetic investigation.

So far, 24 of the 29 amyloid positive patients have completed all clinical investigations and no one fulfilled diagnostic criteria of cardiac amyloidosis.

Conclusion

A significant number of CTRS patients, (14%), had wild-type ATTR amyloidosis confined to the carpal tunnel. None of these had cardiac involvement. These findings were different from the results in the previous prospective study and were likely to be explained by differences in the patient cohorts investigated. We investigated unselected patients in contrast to the highly selected cohort in the previous study.

Based on the findings in the current study the proportion of CTRS patients with localized amyloidosis who may develop systemic disease is unknown. Therefore, it is necessary to perform long term follow-up of these patients before routine investigations for amyloidosis may be recommended.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Financial support was obtained by an unrestricted research grant from Alnylam Pharmaceuticals

FRI0203 A SINGLE-CENTER INVESTIGATION ON THE PREVALENCE OF MALIGNANCIES IN PATIENTS WITH POLYMYALGIA RHEUMATICA AND GIANT CELL ARTERITIS BY WAY OF 18F-FDG PET/CT: A PROSPECTIVE COHORT STUDY

Background:

Several chronic inflammatory diseases are associated with a higher risk of cancer.[1] Whether, this is the case in Polymyalgia Rheumatica (PMR) and Giant Cell Arteritis (GCA) is still a matter of debate.

Objectives:

To identify the prevalence of newly diagnosed cancers in patients with PMR and GCA by means of 18F-FDG PET/CT. Moreover, to compare the characteristics of the patients with and without cancer.

Methods:

Eighty consecutive patients with newly diagnosed PMR/GCA were studied. Diagnosis of PMR/GCA was confirmed by a 40-weeks follow up. A unilateral temporal artery biopsy (TAB) was also performed at the time of diagnosis. All included patients underwent an 18F-FDG PET/CT before, or in case of GCA, within 3 days of initiation of high dose oral glucocorticoid (40-75mg). All cancer-suspicious 18F-FDG-PET/CT findings were assessed thoroughly and malignant diseases were confirmed by histology. Total PMR and GCA scores were defined as the sum of a 4-point visual grading scale in each articular/periarticular site as well as arterial segment.

Results:

Of the 80 patients, 64 (83.1%) were diagnosed with pure PMR, 10 (13.0%) with concomitant GCA with PMR and 3 (3.9%) with pure GCA. Three patients were diagnosed with rheumatoid arthritis during follow up and excluded from the study. Five types of cancer in 4 (5.2%;95% CI:1.4-12.8%) patients were found. Two patients had breast cancer, one patient had adenocarcinoma of colon and one patient had adenocarcinoma of colon together with skin cancer. Besides, 4 (5.2%;95% CI:1.4-12.8%) patients had Monoclonal Gammopathy of Unknown Significance (MGUS). Age and C-reactive protein were significantly higher among those with solid cancers (p:0.049) and MGUS (p:0.017), respectively (Table1).

Table 1.

Characteristics of the patients with and without solid cancer ae well as MGUS

VariablesCancer –,n=73Cancer +,n=4P-valueMGUS -, n =73MGUS +,n =4P-valueAge, mean±SD71.4±7.879.7±7.50.04971.9±8.070.2±9.20.79Gender, n(%)Female46(59.7%)3(3.9%)0.9947(61.0%)2(2.6%)0.62Constitutional symptoms, n(%)70(90.9%)4(5.2%)0.9970(90.9%)4(5.2%)0.99Shoulder girdle symptoms, n(%)68(88.3%)4(5.2%)0.9968(88.3%)4(5.2%)0.99Hip girdle symptoms, n(%)65(84.4%)3(3.9%)0.4064(83.1%)4(5.2%)0.99Cranial symptoms, n(%)19(24.7%)0(0%)0.5717(22.1%)2(2.6%)0.25Patients pain VAS75(50-85)62.5(50-75)0.5372.5(50 -80)87.5(77.5-95)0.07Patients global VAS80(60-90)62.5(50-75)0.3780(60-90)89.5(79.5-95)0.23Physician global VAS30(25-40)24.5(20-29)0.1530(22.5-40)37.5(32.5-45)0.17Erythrocyte sedimentation rate, mm[2-20]54(38-79)62.5(37.5-76)0.9354(38-77.5)57.5(39 -73.5)0.94C-reactive protein, mg/L[<6.0]37(17-64)34(17.0-76)0.8033(17-60)98(68 -115)0.017TAB positive7(9.1%)0(0%)0.997(9.1%)0(0%)0.99Total PMR score14(10-17)12(5-15)0.3914(10-17)13(6-15.5)0.64Total GCA score0(0-0)0(0-0.5)0.890(0-0)0(0-0)0.34Clinical diagnosis, n(%)0.990.53 Pure PMR60(77.9%)4(5.2%)61(79.2%)3(3.9%) Pure GCA3(3.9%)0(0%)3(3.9%)0(0%) Concomitant PMR and GCA10(13.0%)0(0%)9(11.7%)1(1.3%)

VAS: Visual analogue scale

Conclusion:

The prevalence of cancers in this cohort was higher, compared to the 1-year prevalence of all cancer sites of 1.2% among age-, gender- and region-matched background population in 2016. Occult malignancies are important and relatively prevalent findings in newly diagnosed PMR/GCA patients.

References:

[1]Hemminki K, et al. Cancer risk in hospitalized rheumatoid arthritis patients. Rheumatology (Oxford) 2008;47:698-701.

Disclosure of Interests:

None declared

The giraffe kidney tolerates high arterial blood pressure by high renal interstitial pressure and low glomerular filtration rate

BACKGROUND

The tallest animal on earth, the giraffe (Giraffa camelopardalis) is endowed with a mean arterial blood pressure (MAP) twice that of other mammals. The kidneys reside at heart level and show no sign of hypertension-related damage. We hypothesized that a species-specific evolutionary adaption in the giraffe kidney allows normal for size renal haemodynamics and glomerular filtration rate (GFR) despite a MAP double that of other mammals.

METHODS

Fourteen anaesthetized giraffes were instrumented with vascular and bladder catheters to measure glomerular filtration rate (GFR) and effective renal plasma flow (ERPF). Renal interstitial hydrostatic pressure (RIHP) was assessed by inserting a needle into the medullary parenchyma. Doppler ultrasound measurements provided renal artery resistive index (RI). Hormone concentrations as well as biomechanical, structural and histological characteristics of vascular and renal tissues were determined.

RESULTS

GFR averaged 342 ± 99 mL min(-1) and ERPF 1252 ± 305 mL min(-1) . RIHP varied between 45 and 140 mmHg. Renal pelvic pressure was 39 ± 2 mmHg and renal venous pressure 32 ± 4 mmHg. A valve-like structure at the junction of the renal and vena cava generated a pressure drop of 12 ± 2 mmHg. RI was 0.27. The renal capsule was durable with a calculated burst pressure of 600 mmHg. Plasma renin and AngII were 2.6 ± 0.5 mIU L(-1) and 9.1 ± 1.5 pg mL(-1) respectively.

CONCLUSION

In giraffes, GFR, ERPF and RI appear much lower than expected based on body mass. A strong renal capsule supports a RIHP, which is >10-fold that of other mammals effectively reducing the net filtration pressure and protecting against the high MAP.

TMEM16A is a Ca(2+) -activated Cl(-) channel expressed in the renal collecting duct

AIM

In the renal collecting ducts, ATP stimulates a Ca(2+) -activated chloride current. The identity of the channel responsible for the current under physiological conditions is not known and it was hypothesized that TMEM16a is a relevant candidate in the renal collecting duct.

METHODS

The cortical collecting duct cell line M-1 was used as a model of the collecting duct. The ATP induced Ca(2+) signalling was imaged in cells loaded with Ca(2+) -sensitive fluorescent probes using confocal laser-scanning fluorescence microscopy. Chloride current was determined by mounting M-1 cell layers in Ussing chamber. The expression of TMEM16a in human kidney was tested by immunohistochemistry.

RESULTS

M-1 cells displayed a transient increase in intracellular Ca(2+) concentration in response to 100 nm ATP. This response was completely blocked by addition of 100 μm suramin, indicating that ATP signals through purinergic P2 receptors. Apical addition of 100 nm ATP induced a Cl(-) current, which was blocked by suramin, DPC and the cysteine-modifying compound MTSET. M-1 cells were found to express TMEM16a at the mRNA and protein level. Functionally, it was found that knock-down of TMEM16a expression in M-1 cells inhibited the ATP induced Cl(-) -current. In human and mouse kidney sections, TMEM16a protein expression was localized to the collecting duct, and TMEM16a was found to be excreted in human urinary exosomes.

CONCLUSION

TMEM16a is a Ca(2+) -activated Cl(-) channel expressed in the collecting ducts.

Postnatal development of the renal medulla; role of the renin-angiotensin system

Adverse events during foetal development can predispose the individual for cardiovascular disease later in life, a correlation known as foetal programming of adult hypertension. The 'programming' events have been associated with the kidneys due to the significant role in extracellular volume control and long-term blood pressure regulation. Previously, nephron endowment and functional consequences of a low nephron number have been extensively investigated without achieving a full explanation of the underlying pathophysiological mechanisms. In this review, we will focus on mechanisms of postnatal development in the renal medulla with regard to the programming effects. The renin-angiotensin system is critically involved in mammalian kidney development and impaired signalling gives rise to developmental renal lesions that have been associated with hypertension later in life. A consistent finding in both experimental animal models and in human case reports is atrophy of the renal medulla with developmental lesions to both medullary nephron segments and vascular development with concomitant functional disturbances reaching into adulthood. A review of current knowledge of the role of the renin-angiotensin system for renal medullary development will be given.

Transmission of angiosarcomas from a common multiorgan donor to four transplant recipients

We describe the donor tumor transmission of metastatic angiosarcomas to four transplant recipients through transplantation of deceased-donor organs, i.e. kidneys, lung and liver, from an apparently unaffected common female multiorgan donor. Fluorescent in situ hybridization of angiosarcoma cells confirmed that the tumor was of female donor's origin in male kidney recipients. Recent literature associated increased urokinase-plasminogen-activator-receptor (uPAR) and plasma soluble urokinase-plasminogen-activator-receptor (suPAR) levels with metastatic malignancies. Now we found that, compared to baseline levels, both deceased-donor kidney recipients showed increased uPAR transcripts in mononuclear cells as well as increased plasma suPAR levels after the diagnosis of metastatic angiosarcomas, i.e. 4 months after donor tumor transmission. These results show an association of uPAR/suPAR in donor tumor transmission of metastatic angiosarcomas in humans.

Hyponatremia as a prognostic and predictive factor in metastatic renal cell carcinoma

Background:

Low serum sodium has recently been associated with poor survival in localised renal cell carcinoma (RCC). We now show the prognostic effect of serum sodium in patients with metastatic RCC (mRCC).

Methods:

Cohort A comprised 120 consecutive patients with mRCC receiving subcutaneous, low-dose interleukin-2 and interferon-α. Hyponatremia was assessed in univariate and multivariate analyses. An independent cohort of another 120 patients with mRCC was used for validation (cohort B).

Results:

In cohort A, estimated 5-year survival was 15% and median survival was 15.1 months. Serum sodium ranged between 126 and 144 mM. Twenty-four patients (20%) had serum sodium levels below normal range (<136 mM). In multivariate analysis, significant independent risk factors for short survival were low serum sodium (P=0.014), high neutrophils (P=0.018), lactate dehydrogenase >1.5 upper normal level (P=0.002), and number of metastatic sites (+3) (P=0.003). In cohort B, serum sodium ranged between 128 and 146 mM. Seventeen patients (14%) had sodium levels below normal range. In multivariate analysis, serum sodium was validated as an independent prognostic factor (P=0.001). A significant association between lack of response and hyponatremia was observed in both cohorts (P=0.003 and P=0.02, respectively).

Conclusion:

Low serum sodium is a new, validated, independent prognostic, and predictive factor in patients with mRCC.

Serum-sodium as an independent prognostic factor in metastatic renal cell carcinoma

5102

Background: Recently, low serum sodium has been associated with poor disease-free and overall survival in localized renal cell carcinoma (RCC) (Vasudev, Clin Can Res. 2008). The present study investigated the prognostic impact of serum-sodium values below normal in patients with metastatic RCC (mRCC). Methods: A cohort of 120 consecutive patients with mRCC received subcutaneous, low-dose Interleukin-2 and Interferon-α at Dept. of Oncology, Aarhus University Hospital, from 2002 to 2004 (Cohort A). Baseline variables were collected retrospectively. Follow up was at least 4 years. Potential prognostic factors were analyzed by univariate and multivariate analyses. Endpoint was overall survival. An independent cohort of 120 consecutive patients with mRCC was used for validation. These patients were treated with interleukin-2 based regimens at the same institution from 1999 to 2002 (Cohort B). Data in this cohort were prospectively collected. Results: In cohort A, the estimated 5-year survival rate was 15% and the median survival was 15.1 months. Serum-sodium ranged between 126 and 144 mmol/l. Twenty-four patients (20%) had serum-sodium levels below normal range (<136 mmol/l). In the multivariate analysis, significant independent risk factors of short survival were serum-sodium below normal value (HR 1.90, CI 1.1–3.2, p = 0.014), high neutrophile count (>7) (HR 1.75, CI 1.1–2.8, p = 0.018), lactate dehydrogenase >1.5 upper normal level (HR 2.09, CI 1.3–3.3, p = 0.002), and number of sites (+3) (HR 1.92; CI 1.3–2.9, p = 0.003). In cohort B, the observed 5-year survival rate was 15% and the median survival was 15 months. Serum-sodium ranged between 128 mmol/l and 146 mmol/l. Seventeen patients (14%) had sodium levels below normal range. In the multivariate analysis, serum-sodium was validated as an independent prognostic factor (HR 2.98, CI 1.54–5.77, p = 0.001). Conclusions: Low serum-sodium is a new, validated, independent prognostic factor in patients with metastatic RCC.

No significant financial relationships to disclose.

Temporal profile of calcineurin phosphatase activity during acute allograft rejection in the heterotopic rat heart transplantation model

BACKGROUND

Regardless of the extensive worldwide use of calcineurin inhibitors, little is known about the behavior of calcineurin phosphatase (CaN) during acute allograft rejection. The aim of this study was to investigate the temporal profile of CaN during acute allograft rejection and reveal if it can be utilized as a pharmacodynamic marker to identify and monitor the rejection process.

METHODS

The heterotopic cervical rat heart transplantation model was used (dark Agouti to Lewis). We performed 25 control isogeneic and 46 allogeneic transplantations. Rats were sacrificed at various postoperative time points. CaN activity was measured in isolated peripheral blood and spleen mononuclear cells and in graft heart homogenates. CaN activity was measured as the release of radiolabeled phosphate from a previously phosphorylated 19 amino acid peptide.

RESULTS

We have shown that CaN's activity levels are not significantly altered during acute allograft rejection in peripheral blood mononuclear cells and in spleen-isolated mononuclear cells. CaN's intragraft activity decreased with time in both rejectors and controls, and was significantly lower in the allogeneic group.

CONCLUSIONS

CaN failed as a pharmacodynamic biomarker of acute allograft rejection in the heterotopic rat heart transplantation model. Further research is required in order to reveal the precise role of CaN during acute allograft rejection.

MLPA and cDNA analysis improves COL4A5 mutation detection in X-linked Alport syndrome

The X-linked form of Alport syndrome (AS) is caused by mutations in the COL4A5 gene encoding the alpha5 chain of type IV collagen. Most COL4A5 mutations are individual, and mutation analysis is complicated by the size of the gene and the number of exons. Larger structural rearrangements account for 10-15% of mutations. We have established a method for mutation analysis of COL4A5 based on reverse transcriptase-polymerase chain reaction analysis of mRNA from cultured skin fibroblasts and multiplex ligation-dependent probe amplification (MLPA) on genomic DNA. One advantage of using skin biopsies for the mRNA analysis is the possibility of immunohistochemical staining for the alpha5(IV) chain on skin sections to support a diagnosis of X-linked AS. A mutation was detected in all five cases included. One patient presenting with AS and diffuse leiomyomatosis was found to have a COL4A5 deletion extending into and comprising COL4A6 exons 1, 1', and 2. We have evaluated the MLPA assay on samples from 67 previously tested AS patients (45 males and 22 females) and 20 controls. We found that the combination of cDNA and MLPA analysis improves the mutation detection rate in COL4A5 and that MLPA should be the first step in genetic testing for X-linked AS.

Kidney Volume Increases During Long-Term Ciclosporin A Treatment

PURPOSE

Previously, we have for the first time reported enlargement of the pig kidney during long-term ciclosporin (CsA) treatment. In this paper, we summarize our findings of renal enlargement during long-term protocols with various dosages and durations of CsA administration as well as discuss possible pathogenetic mechanisms.

MATERIALS AND METHODS

Twenty-two adolescent Gottingen minipigs were allocated into four groups: group A (n = 6) served as controls for 6 months; group B (n = 5) were treated with CsA (10 mg/kg per day) for 6 months, group C (n = 4), with CsA (20 mg/kg per day) for 6 months, and group D (n = 7) with CsA (10 mg/kg per day) orally for 12 months. At regular intervals, renal length and total volume were measured using magnetic resonance imaging; renal biopsies were performed for histological examination.

RESULTS

A significant increase in kidney volume occurred in all CsA-treated pigs (groups B, C, and D); whereas the volume remained stable in the control animals (group A). A small but significant rise in kidney length was observed in groups A, B, and C, probably due to the normal growth of the animals. Histological examination was normal after treatment with CsA doses of 10 and 20 mg/kg per day for 6 months but showed definite interstitial fibrosis and glomerulosclerosis after treatment with 10 mg/kg per day CsA for 12 months.

CONCLUSION

Long-term CsA treatment produced renal enlargement in pigs before the development of histological changes in the kidney. Thus, renal enlargement may represent an early stage of chronic CsA nephrotoxicity.

Chronic cyclosporine nephrotoxicity: a pig model

Cyclosporine A (CsA) is one of the keystones in immunosuppressive treatment after solid organ transplantation, despite its major side effects such as nephrotoxicity. The chronic nephrotoxic effects of CsA seen in humans have been difficult to reproduce in small-animal models. The aim of the present study was to examine the chronic nephrotoxicity produced by therapeutic dosages of CsA in a pig model. Among 11 Gottingen minipigs included in the study, three died, yielding data from five animals given CsA (10 mg/kg/d, orally) for 6 months, and three controls. Body weight, blood pressure, glomerular filtration rate (GFR) by plasma clearance of (51)Cr-ethylenediamine-tetraacetic acid, CsA concentration, serum creatinine, and other values were measured every 5 weeks. Our results showed that the whole blood trough CsA levels were lower in pigs than in humans treated with similar CsA doses. Renal biopsies, which were obtained successfully, except one case of macroscopic hematuria, showed no histological changes in the kidney. No significant increase in serum creatinine or blood pressure was observed. Surprisingly, there was a significant increase in GFR during CsA treatment. We conclude that the pig model displays a hyperfiltration that warrants further investigation.

Monocytes and neutrophils as 'bad guys' for the outcome of interleukin-2 with and without histamine in metastatic renal cell carcinoma--results from a randomised phase II trial

Histamine (HDC) inhibits formation and release of phagocyte-derived reactive oxygen species, and thereby protects natural killer (NK) and T cells against oxidative damage. Thus, the addition of histamine may potentially improve the efficacy of interleukin-2 (IL-2). We have explored this potential mechanism clinically in two randomised phase II trials in metastatic renal cell carcinoma (mRCC). In parallel with the clinical trial in Denmark (n=63), we obtained serial blood samples and tumour biopsies searching for a potential histamine effect in situ. At baseline and on-treatment weeks 3 and 8, we monitored the ‘good guys’ (i.e. NK and T cells) and ‘bad guys’ (i.e. monocytes/macrophages and neutrophils) simultaneously in blood (n=59) and tumour tissue (n=44). Patients with high number of monocytes and neutrophils in peripheral blood had very poor survival, with apparently no benefit from either IL-2 alone or IL-2/HDC treatment. Blood monocytes (r=−0.36, P=0.01) and neutrophils (r=−0.46, P=0.001) were negatively correlated with cytotoxicity, whereas blood NK cells were positively correlated with cytotoxicity (r=0.39, P=0.002). Treatment with IL-2 alone resulted in a significantly higher number of circulating monocytes (P=0.037) and intratumoral macrophages (P=0.005) compared with baseline. In contrast, IL-2/HDC resulted in an unchanged number of circulating monocytes and intratumoral macrophages, and in addition, a significantly increased number of intratumoral CD56⁺ NK cells (P=0.008) and CD8⁺ T cells (P=0.019) compared with baseline. The study provides evidence that circulating monocytes and neutrophils are powerful negative prognostic factors for IL-2-based immunotherapy and establishes a biological rationale for the potential use of histamine in conjunction with IL-2 in mRCC.

Gene expression profiling of noninvasive primary urothelial tumours using microarrays

At present, the mechanism leading to bladder cancer is still poorly understood, and our knowledge about early events in tumorigenesis is limited. This study describes the changes in gene expression occurring during the neoplastic transition from normal bladder urothelium to primary Ta tumours. Using DNA microarrays, we identified novel differentially expressed genes in Ta tumours compared to normal bladder, and genes that were altered in high-grade tumours. Among the mostly changed genes between normal bladder and Ta tumours, we found genes related to the cytoskeleton (keratin 7 and syndecan 1), and transcription (high mobility group AT-hook 1). Altered genes in high-grade tumours were related to cell cycle (cyclin-dependent kinase 4) and transcription (jun d proto-oncogene). Furthermore, we showed the presence of high keratin 7 transcript expression in bladder cancer, and Western blotting analysis revealed three major molecular isoforms of keratin 7 in the tissues. These could be detected in urine sediments from bladder tumour patients.

In vivo assessment of the antiproliferative properties of interferon-alpha during immunotherapy: Ki-67 (MIB-1) in patients with metastatic renal cell carcinoma

The aim of the present study was to investigate the in vivo antiproliferative effect of interferon alpha (IFN-α) in patients with metastatic renal cell carcinoma (mRCC). Core needle biopsies of metastatic and/or the primary kidney cancer were obtained before interleukin-2 (IL-2)- and IFN-α-based immunotherapy in 34 patients and repeated after 5 weeks in 25 patients. Tumour proliferation was assessed by use of the anti-Ki-67 antibody MIB-1 and evaluated in multiple, random systematic sampled fields of vision. Ki-67 labelling index (LI) at baseline was median 13.6% (range 1.2–85.0) and median 10.6% (range 1.3–48.6%) at week 5 with a median overall decline of 15.2% (range −95 to +258%) from baseline to week 5. There was no difference between responding and nonresponding patients. Ki-67 LI at week 5 was significantly correlated to survival. Thus, median survival of patients with Ki-67 LI ⩽10.6% at week 5 was 25.1 months compared to 11.5 months for patients with Ki-67 LI >10.6% (P=0.016). Baseline or change in Ki-67 LI did not correlate to survival. These data suggest that IFN-α in vivo has only modest effect on tumour proliferation in patients with mRCC. Tumour Ki-67 (MIB-1) reactivity after 1 month of immunotherapy appears to be a significant predictor of patient survival.

Retinoblastoma protein expression is an independent predictor of both radiation response and survival in muscle-invasive bladder cancer

The objective of the study was to investigate the predictive value of various clinical, biochemical, and histopathological parameters, with special emphasis on the expression of the retinoblastoma protein (pRB), on the radiation response in bladder cancer. In order to obtain a truly objective response measure, patients receiving preoperative radiotherapy followed by cystectomy were studied. Pretreatment tumour samples and clinical data from 108 consecutive patients were collected. End points were complete response (CR) to radiotherapy, relapse-free survival time and overall survival time. Expression of pRB was assessed by immunohistochemical staining as present or absent. Complete response to radiotherapy was obtained in 42 of 106 evaluable patients (40%). Predictive for CR to radiotherapy, in univariate analysis, was transurethral resection (as opposed to biopsy), B-haemoglobin, no upper urinary retention, and loss of pRB staining. Loss of pRB staining was the strongest independent predictor of radiation response in multivariate logistic regression analysis and absence of upper urinary retention was the only other significant factor. Loss of pRB was the only parameter showing statistically significant, independent association with relapse-free survival, whereas B-haemoglobin was also independently associated with overall survival. Loss of pRB expression seems to indicate a phenotype displaying enhanced radiosensivity and may be of benefit by denoting patients who would selectively benefit from a treatment schedule containing radiotherapy.

Intense inflammation in bladder carcinoma is associated with angiogenesis and indicates good prognosis

The aim of this study was to investigate the prognostic influence of microvessel density using the hot spot method in 107 patients diagnosed with transitional cell carcinoma of the bladder. In each case, inflammation was found in the invasive carcinoma, therefore we classified the degree of inflammation as minimal, moderate or intense. Microvessel density was then reevaluated in each tumour in areas corresponding to these three categories. Median microvessel density irrespective of degree of inflammation was 71. Areas of minimal, moderate and intense inflammation were found in 48, 92 and 32 tumours. Microvessel density increased significantly with increasing degree of inflammation. Disease-specific survival was improved if areas of intense inflammation were present in the carcinoma (P=0.004). High microvessel density, irrespective of the degree of inflammation, was associated with a significantly better disease-specific survival (P=0.01). Multivariate analysis using death of disease as endpoint demonstrated an independent prognostic value of N-classification (N0, hazard ratio (HR)=1 vs N1, HR=2.89 (range, 1.52-5.52) vs N2, HR=3.61 (range, 1.84-7.08)), and intense inflammation, HR=0.48 (range, 0.24-0.96). Malignancy grade, T classification and microvessel density were not independent significant markers of poor outcome. In conclusion, inflammation was significantly correlated to microvessel density, and areas of intense inflammation were an independent marker of good prognosis.

Intratumoural and peripheral blood lymphocyte subsets in patients with metastatic renal cell carcinoma undergoing interleukin-2 based immunotherapy: association to objective response and survival

The aim of the present study was to analyse lymphocyte subsets in consecutive peripheral blood samples and consecutive tumour tissue core needle biopsies performed before and during interleukin-2 based immunotherapy, and to correlate the findings with objective response and survival. Twenty-six patients with metastatic renal cell carcinoma were treated with low dose s.c. interleukin-2, interferon-alpha and histamine. A total of 250 blood samples and 62 core needle biopsies from 23 and 19 of these patients, respectively, were analysed. After 2 weeks of treatment, a significant positive correlation between absolute number of peripheral blood lymphocytes (P=0.028), CD3 (P=0.017), CD57 (P=0.041) and objective response was demonstrated. There was no correlation between any peripheral blood leukocyte subsets and survival. Cytotoxicity of peripheral blood mononuclear cells was not correlated to objective response or survival. Within the tumour tissue at baseline, a significant positive correlation between CD4 (P=0.027), CD8 (P=0.028), CD57 (P=0.007) and objective response was demonstrated. After one month of immunotherapy, a significant positive correlation between intratumoral CD3 (P=0.026), CD8 (P=0.015), CD57 (P=0.009) and objective response was demonstrated. A significant positive correlation between intratumoral baseline CD4 (P=0.047), baseline CD57 (P=0.035), CD3 at one month (P=0.049) and survival was demonstrated. These data provide novel in vivo evidence of the possible contribution of lymphocyte subsets in the tumour reduction in responding patients during interleukin-2 based immunotherapy. Confirmation of the results requires further studies including a larger number of patients.

Loss of heterozygosity at 1p, 8p, 10p, 13q, and 17p in advanced urothelial cancer and lack of relation to chemotherapy response and outcome

Studies of urothelial tumors have identified structural abnormalities in a number of chromosomes. This study aimed to identify specific genetic changes of patients with advanced urothelial cancers, and relate these changes to increased chemotherapy sensitivity or good prognosis. We screened 56 muscle-invasive bladder cancer tumors for loss of heterozygosity (LOH) at chromosome 1p, 8p, 10p, 13q, and 17p with PCR using 6 microsatellite markers. All patients had recurrent locally advanced or metastatic disease. DNA was extracted after microdissection of the primary tumor and normal tissue from paraffin-embedded specimens. The PCR products were electrophoresed in an ABI Prism 377 DNA sequencer and the alleles from tumor DNA and normal tissue DNA were analyzed using the GeneScan program. The LOH findings were correlated with response to chemotherapy and survival. Allelic loss of specific markers was present in 26-50% of the informative tumors. The most frequent LOH was observed at 17p, supporting the notion that this region may contain genes of importance to urothelial cancer progression. The overall rate of response to chemotherapy was 48%, and ranged from 40% to 56% according to specific LOH changes. The median survival of all patients from start of chemotherapy was 5.8 months and ranged from 5.3 to 7.9 months for patients with specific LOH changes. Response and survival of patients with no lost markers was the same size, compared to patients with one, two, or more lost markers. Specific genetic changes were detected in a significant number of tumors from patients with advanced urothelial cancer. These changes were not predictive of response to chemotherapy or of the duration of survival.

Glomerular structure in lithium-induced chronic renal failure in rats

The effects of long-term lithium administration on glomerular structure and intervention with angiotensin converting enzyme inhibitor (ACEI) were studied in rats. Male Wistar rats were fed a lithium-containing diet (Li) or control diet (C) for 16 weeks postnatally. Li-treated rats developed renal failure, hypertension and proteinuria. During the subsequent 24 weeks, subgroups were treated with ACEI. The kidneys were fixed by perfusion, and tissue blocks were serially cut for estimation of glomerular volume and glomerular characteristics by light microscopy. Mesangial and mesangial matrix volume fractions, surface density of capillary walls, basement membrane thickness and foot process width (FPW) were measured by electron microscopy. Glomerular volume was decreased in Li-rats, with increased intra-individual variation. In all Li-rats, some glomeruli (mean 27%) were abnormal, with severe changes in only three rats. Ultrastructural parameters obtained by systematic sampling of three glomeruli in each rat showed no differences among groups. Among Li-treated animals there was a significant correlation between FPW and albumin excretion per unit filtration surface, and between filtration surface per glomerulus and inulin clearance. In conclusion, long-term lithium administration to newborn rats caused marked changes in glomerular volume which were not associated with measurable changes in structural parameters. No effect of ACEI-treatment was detectable.

IGF-I treatment attenuates renal abnormalities induced by neonatal ACE inhibition

An intact renin-angiotensin system (RAS) during nephrogenesis is essential for normal renal development. We have shown previously that neonatal inhibition of the RAS, either with ANG II type 1-receptor blockade or angiotensin-converting enzyme (ACE) inhibition, induces irreversible renal abnormalities. The aim of the present study was to investigate whether an interrupted RAS can be compensated for by exogenous administration of another important renal growth-promoting factor, the insulin-like growth factor-I (IGF-I). Rats were treated daily with either the ACE inhibitor enalapril (10 mg/kg), recombinant human IGF-I (3 mg/kg), or the combination enalapril + IGF-I from perinatal day 3 to 13. Urinary concentrating ability, renal function, and renal morphology were assessed at adult age. The gene expression and localization of IGF-I, its receptor, and the growth hormone receptor (GHR) were investigated during ongoing ACE inhibition. The present study demonstrates normalized renal function and histology in enalapril + IGF-I-treated animals. Ongoing ACE inhibition suppressed the medullary IGF-I mRNA expression and altered the local distribution of both IGF-I and GHR. Thus the present study provides evidence for an interaction between the RAS and GH/IGF-I axis in renal development.

Postnatal time frame for renal vulnerability to enalapril in rats

Angiotensin-converting enzyme inhibition or angiotensin II type 1 receptor blockade in neonatal, but not in weaned, rats induces irreversible renal histologic abnormalities and an impaired urinary concentrating ability. The aim of the present study was to define the postnatal time frame when the rat kidney is vulnerable to an interruption of the renin-angiotensin system. Male Wistar rats received daily injections of enalapril (10 mg/kg, intraperitoneally) during different age intervals within 3 to 24 d,of age. Fluid handling and urinary concentrating ability, renal function under pentobarbital anesthesia, and kidney histology using stereologic techniques were evaluated in adult rats. Enalapril treatment within 3 to 13 d after birth induced abnormalities in renal function and morphology long-term, whereas treatment initiated at 14 d of age did not. The main histologic alterations were papillary atrophy, and a reduction in the volume of tubular epithelial cells in association with an increase in the proportion of interstitium, throughout the cortex and outer medulla. Functionally, the predominant defect was an impairment in urinary concentrating ability, which correlated with the degree of papillary atrophy. In conclusion, the vulnerable age interval for the induction of irreversible renal abnormalities by enalapril was the first 13 d after birth in the rat. This postnatal time span coincides with the completion of nephrogenesis and a period of marked tubular growth and differentiation, suggesting a pivotal role for angiotensin II in these processes.

Effects of chronic octreotide treatment on renal changes during cirrhosis in rats

We examined the effect of a new long-acting release formula (LAR) of the somatostatin analogue, octreotide, on development of sodium retention and functional and structural changes in the thick ascending limb of Henle's loop (TAL) in rats with cirrhosis induced by common bile duct ligation (CBL). CBL and sham-operated control rats were treated with octreotide-LAR (10 mg/kg body weight subcutaneously, as a single dose) or vehicle at the time of CBL or sham-CBL. The rats were instrumented with chronic catheters, and sodium balance and renal function were examined 4 weeks after CBL or sham operation. Octreotide-LAR treatment significantly inhibited sodium retention in CBL rats and prevented renal vasodilatation without changes in glomerular filtration rate (GFR). The natriuretic response to a test dose of furosemide (7.5 mg/kg body weight intravenously) was significantly increased in CBL rats, and when expressed in terms of natriuretic efficiency (mmol Na/mg furosemide in urine), the natriuretic response was increased by 57% relative to sham-operated controls. Stereological examination of kidneys demonstrated a 53% increase in the volume of the inner stripe of the outer medulla and a 108% increase in the volume of TAL epithelium in cirrhotic rats relative to controls. The increased natriuretic efficiency of furosemide as well as the hypertrophy of the inner stripe and the TAL in this renal zone were absent in CBL rats treated with octreotide-LAR. These results suggest that octreotide-LAR treatment inhibits sodium retention in cirrhotic rats, partly by inhibition of increased furosemide-sensitive sodium reabsorption in the TAL.

[Renal biopsy in connection with long-term treatment of psoriasis with cyclosporine]

Renal biopsies were performed in 30 psoriatics during long-term low-dose cyclosporin (CSA) therapy (range 2.5-6 mg/kg/day) of from six months to eight years. The study included pretreatment biopsies in 25 of the patients. After two years all biopsies shared features consistent with CSA nephropathy despite completely normal pretreatment morphology in 18 of the 25 patients. The severity of the findings, which consisted of arteriolar hyalinosis, focal interstitial fibrosis and sclerotic glomeruli, increased with length of therapy. Mild renal lesions were seen during the first two years. After four years all but one had arteriolar hyalinosis, with interstitial fibrosis pronounced in five and moderate in six of 11 patients. At the same time glomerular sclerosis had become significant. A decrease in glomerular filtration rate (GFR) correlated with the severity of the fibrosis. GFR studied in 14 patients six months to seven years after discontinuation of CSA was still significantly decreased in relation to baseline prior to therapy. The data from our study together with experiences from cardiac-transplanted patients indicate that patients with psoriasis, after two years therapy with CSA, should be rotated to other treatments or be followed carefully by GFR and sequential renal biopsies.

Urinary acidification and net acid excretion in adult rats treated neonatally with enalapril

Neonatal blockade of the renin-angiotensin system in rats induces irreversible renal histological abnormalities, including papillary atrophy and an impaired urinary concentrating ability. The aim was to investigate urinary acidification and net acid excretion in adult Wistar rats treated neonatally with enalapril (10 mg . kg-1 . day-1) or vehicle from 5 to 24 days of age. Analyses were performed in both metabolic balance studies and renal clearance experiments performed under pentobarbital sodium anesthesia. There were no differences between groups in urine pH or urinary excretion rates of bicarbonate, titratable acid, or ammonium, neither during control conditions nor after chronic NH4Cl loading (assessed before and after Na2SO4 infusion). Glomerular filtration rate, maximal tubular bicarbonate reabsorption, and the urine-to-blood PCO2 gradient in alkaline urine during NaHCO3 infusion did not differ between groups. Neonatally enalapril-treated rats showed a urine concentration defect and papillary damage. In conclusion, neonatal enalapril treatment produces a differentiated abnormality in tubular function in which urine concentration is impaired but urinary acidification and net acid excretion are intact.

A quantitative immunohistochemical study of the expression of mesangial alpha-smooth muscle actin and the proliferation marker Ki-67 in glomerulonephritis in man

Using a specific marker 1A4 (DAKO), a quantitative evaluation of alpha-smooth muscle actin (ASMA) in glomeruli has been performed on human renal biopsies from patients suffering from acute, postinfectious, endocapillary glomerulonephritis (GN; 9 biopsies), IgA nephropathy (11 biopsies) and membranoproliferative GN (11 biopsies) and appropriate controls expressing a very weak ASMA reactivity. A significantly increased expression was found in all categories of GN. The glomeruli from IgA nephropathy showed variation of ASMA expression (range 0.1-27.7%) and a pattern of ASMA staining that was mesangial, global and diffuse. This pattern was also seen in cases of IgA nephropathy with focal, segmental, proliferative GN. In all biopsies, the glomerular cell number and proliferation index was determined. All the categories of GN showed significantly increased glomerular cellularity and proliferation index. Among the three types of GN, the glomerular cellularity and proliferation was lowest in IgA nephropathy. The mean number of Ki-67-positive intraglomerular nuclei and the proliferation index were both significantly correlated with the mean number of glomerular cell nuclei. Morphometric estimates demonstrate increased ASMA expression in types of GN with different prognosis. This finding and the lack of correlation with proliferation markers together indicate that the role of ASMA in GN is complex. This method of ASMA estimation may be useful in further studies of its role in disease activity and prognosis.

Kidney allograft with a lymphocytic infiltrate: acute rejection, posttransplantation lymphoproliferative disorder, neither, or both entities?

The two cases presented illustrate the diagnostic difficulties and recommend an approach to use in patients in whom features of acute renal allograft rejection and posttransplant lymphoproliferative disorder (PTLD) appear simultaneously in allograft biopsies. Both patients developed acute allograft rejection episodes in the early post-transplant period followed by severe immunosuppression (OKT-3) and active Epstein-Barr virus infection. In addition to early recognition of light microscopic features of PTLD, immunohistology and in situ hybridization for EBV complement the diagnostic work-up and provide clues to the prompt diagnosis of rapidly developing PTLD affecting the allograft even in the face of persisting rejection.

Functional and structural changes in the thick ascending limb of Henle's loop in rats with liver cirrhosis

Five weeks after common bile duct ligation (CBL), Wistar rats had histologically verified liver cirrhosis with sodium retention but without ascites. Plasma concentrations of vasopressin and aldosterone were normal. Glomerular filtration rate was unchanged, although renal plasma flow was increased. A test dose of furosemide (7.5 mg/kg body wt iv) produced significantly greater diuretic (+59%) and natriuretic (+66%) responses in Wistar CBL rats than in sham-operated controls. Stereological examination of kidneys demonstrated a 47% increase in the volume of the inner stripe of the outer medulla, with a 55% increase in the volume of thick ascending limb of Henle's loop (TALH) epithelium in cirrhotic Wistar rats relative to controls. CBL produced a similar degree of liver cirrhosis in vasopressin-deficient Brattleboro rats. However, both functional and structural renal changes observed in cirrhotic Wistar rats were absent in vasopressin-deficient cirrhotic Brattleboro rats. These results suggest a permissive action of vasopressin for the adaptive changes in TALH in rats with experimental liver cirrhosis. Our results are consistent with the hypothesis that increased sodium chloride reabsorption in the TALH may contribute to the early sodium retention that precedes ascites formation in rats with secondary biliary liver cirrhosis.

Renal biopsy findings in long-term cyclosporin treatment of psoriasis

Renal biopsies were performed in 30 psoriatics during long-term low-dose cyclosporin (CsA) therapy (range 2.5-6 mg/kg per day) of from 6 months to 8 years. The study included pretreatment biopsies in 25 of the patients. After 2 years all biopsies shared features consistent with CsA nephropathy despite completely normal pretreatment morphology in 17 of the 25 patients. The severity of the findings which consisted of arteriolar hyalinosis, focal interstitial fibrosis and sclerotic glomeruli increased with length of therapy. Mild renal lesions were seen during the first 2 years. After 4 years all but one had arteriolar hyalinosis, with interstitial fibrosis pronounced in five and moderate in six of 11 patients. At the same time glomerular sclerosis had become significant. A decrease in glomerular filtration rate (GFR) correlated with severity of structural lesions. The data from our study together with experiences from cardiac-transplanted patients treated with CsA indicate that patients with psoriasis after 2 years therapy with CsA should be rotated to other treatments or be followed carefully by GFR and sequential renal biopsies.

Effects of perindopril and hydrochlorothiazide on the long-term progression of lithium-induced chronic renal failure in rats

Administration of lithium in the diet to new-born rats induces chronic renal failure associated with hypertension, proteinuria and irreversible tubulo-interstitial morphological changes. In the present study we induced chronic renal failure by administration of lithium for 16 weeks to new-born rats, and examined the spontaneous course of this nephropathy and the effects of antihypertensive treatment with either perindopril (12 mg/kg diet) or hydrochlorothiazide (500-1000 mg/kg diet) during a 24 weeks follow up period without lithium. In the placebo group, progression to terminal uraemia occurred in all rats with severe renal failure (initial Purea > 15 mM) (10 of 18). Rats with mild-moderate renal failure (Purea 9-15 mM) showed no deterioration in renal function despite persistent systolic hypertension and irreversible structural renal changes. Perindopril normalized the blood pressure in all rats but did not prevent the progression to terminal uraemia (8 to 18). Hydrochlorothiazide partially controlled the hypertension and accellerated the progression of uraemia without increasing the mortality (7 of 17). Irrespective of treatments, the predominant quantitative structural changes (e.g. decreased volume of proximal tubular cells) showed significant correlations with the degree of renal dysfunction, but not with systolic blood pressure in the surviving rats. It is concluded that progression of lithium-induced nephropathy to terminal uraemia occurs when the nephrotoxic insult results in a more than 50% reduction of the glomerular filtration rate, judged from Purea levels. The failure of effective antihypertensive treatment with an angiotension-converting enzyme inhibitor to modify the progression suggests that in this model, systemic or glomerular hypertension may not be an important pathophysiological factor. The structural and functional deterioration observed in Li-uraemic rats during treatment with hydrochlorothiazide remains unexplained.

Effects of renal papillary-medullary lesion on the antihypertensive effect of furosemide and development of salt-sensitive hypertension in Dahl-S rats

To test the hypothesis that the long-term antihypertensive action of furosemide is mediated by a renomedullary vasodepressor substance, we measured mean arterial pressure (MAP) by radiotelemetry in Dahl-S rats with either intact or bromoethylamine-induced (BEA, 100 mg/kg i.p.) lesion of the renal papilla and medulla. Seven days of recovery after BEA administration, the rats diet was changed from 1 to 4% NaCl, and during days 8 to 31, rats were randomized to daily treatment with placebo or furosemide (50 mg/kg p.o.). Then furosemide treatment was stopped and the rat food was changed to 1% NaCl diet. After a 10-day wash-out period, renal function was measured. BEA produced a rapid (within min) and sustained increase in MAP which was accelerated during 4% NaCl diet. Furosemide prevented 4% NaCl-induced hypertension in both rats with intact kidneys and in rats with BEA-induced renal papillary-medullary lesion. A significant decrease in renal plasma flow (-34%) and glomerular filtration rate (-40%) was observed in all BEA-treated rats independent of previous furosemide treatment. In response to an i.v. load of isotonic saline (10% body weight), rats with renal papillary-medullary lesion had an impaired ability to excrete sodium. Histological examination showed that BEA-treated rats had severe lesions of the renal papilla and medulla, with light-to-moderate changes in the renal cortex. It is concluded that the antihypertensive effect of furosemide is not mediated by a renomedullary vasodepressor substance. The accelerated NaCI-sensitive hypertension in rats with BEA-induced renal papillary-medullary lesion is related to an impaired ability to excrete excess NaCl.

Tubulitis in primary vascular and glomerular renal disease

A semiquantitative light microscopic study of 274 renal biopsy and 12 nephrectomy specimens was carried out to assess the frequency and severity of tubulitis (mononuclear leukocytes in the renal tubular wall) in all common glomerular diseases, diabetic nephropathy, renal amyloidosis and renal artery stenosis. The extent of interstitial inflammatory infiltrates and severity of interstitial fibrosis were also graded. Tubulitis was 1) frequent in crescentic glomerulonephritis (GN) with pauci-immune, linear and granular immune deposits, renal artery stenosis, diabetic nephropathy, lupus GN of WHO type IV, and IgA GN; 2) rare in minimal change and idiopathic membranous nephropathy; 3) usually severe in crescentic GN and renal artery stenosis; and 4) predominantly located in atrophic tubules in renal artery stenosis, diabetic nephropathy and IgA GN. The most important parameter for the grading of tubulitis was interstitial infiltration. However, no correlation was found between the grades of tubulitis, interstitial infiltrates and interstitial fibrosis in crescentic and lupus GN. It is suggested that renal ischemic injury, by eliciting expression of proinflammatory cytokines and neo-antigens in the tubulointerstitial space, might play a role in the development of tubulitis in vascular and glomerular renal diseases.

Reproducibility of the Banff classification of renal allograft pathology. Inter- and intraobserver variation

The present study was undertaken to investigate the inter- and intraobserver variation in use of the scoring system for glomerulitis, vasculitis, interstitial inflammation, tubulitis and arteriolar hyalinosis that is an essential part of the recently proposed Banff classification of renal allograft biopsies. Seventy-seven biopsies done less than 90 days after transplantation were included. The scoring was done blindly by five pathologists on biopsies stained with H&E and PAS. The volume fraction of interstitial inflammation was estimated. Spearman rank correlation coefficient and kappa values were used for the evaluation of reproducibility. The results of both inter- and intraobserver variability showed a good correlation and reasonable kappa values for vasculitis, interstitial inflammatory infiltration, and tubulitis. Less-good correlation was found for glomerulitis and arteriolar hyalinosis. The interobserver kappa score for grading of the rejection severity was 0.40 overall but 0.56 when only presence or absence of acute rejection was considered and 0.66 for presence or absence of vasculitis. Weighted kappa values for interobserver vasculitis score and rejection grading were 0.58 and 0.55, respectively. A strong association existed between the volume fraction of interstitial inflammation and the semiquantitative scoring for interstitial inflammation. In conclusion, the good correlations for the key elements in the grading of the allograft biopsies in the present classification system, confirmed the utility of the defined criteria for grading rejection. More precisely defined criteria or simplification of the scoring system are needed for glomerulitis and arteriolar hyalinosis--parameters not used in the diagnosis of rejection.

Cytodiagnostic urinalysis is very useful in the differential diagnosis of acute renal failure and can predict the severity

Cytodiagnostic urinalysis was tested to determine its utility in the differential diagnosis of acute renal failure (ARF). Fifty-one patients with acute renal failure were included and evaluated clinically with regard to the etiology of the renal failure, whether underlying chronic renal failure was present, and if dialysis was required. Urine specimens were macroscopically examined and subjected to a multiparameter reagent-strip analysis. Papanicolaou stain was done on cytocentrifuge preparations and the number of blood cells, renal cells, and casts examined in a standardized fashion. The results showed that the 34 patients with acute tubular necrosis (ATN) of either ischemic or toxic origin had a higher number of collecting duct cells, and a higher total number of casts than the 17 non-ATN patients. Twelve patients requiring dialysis had a higher number of different types of casts (granular, waxy, leukocytic, broad casts) as well as more renal cells (mainly necrotic) than the 39 patients who did not require dialysis. A significant positive correlation was found between the magnitude of rise of serum creatinine and a number of cytodiagnostic parameters. We conclude that cytodiagnostic urinalysis may be valuable in addition to other tests in the evaluation of patients with acute renal failure.

Reproducibility of the WHO classification of glomerulonephritis

The inter-observer variation of the WHO classification of glomerulonephritis (GN) was studied using Kappa statistics. One hundred renal biopsies were selected with almost equal representation of the following types of GN: minimal change nephropathy, membranous GN, focal proliferative GN, diffuse mesangial proliferative GN, endocapillary GN, membranoproliferative GN, and crescentic GN. Slides stained with silver-methenamine and PAS-hematoxylin were circulated among the members of the panel, who made their diagnoses without knowing those of the other participants and without knowledge of the clinical conditions. There was a very good overall diagnostic agreement of 0.67 with a Kappa value of 0.61, figures which compete very well with other diagnostic systems analysed with Kappa statistics. Analysing the single types of GN, we found that the highest Kappa values were obtained for crescentic GN (0.81), endocapillary GN (0.79) and membranous GN (0.74) and the lowest Kappa values for membranoproliferative GN (0.40) and diffuse mesangial proliferative GN (0.44). Basically, the international classification of GN is founded upon light microscopy. Our results demonstrate that this system works generally well. The diagnostic reproducibility of the types with less satisfactory Kappa values can be expected to be improved by including immunopathology and electron microscopy.

Endocapillary glomerulitis in the renal allograft

Endocapillary glomerulitis is characterized by an increase in number of mononuclear cells in the glomerular capillary lumina. This lesion has been described in the early posttransplant period, but its pathogenesis, relation to conventional rejection, and prognostic impact is not well known. Using the definitions, scorings, and gradings of the Banff system for classification and grading of histopathologic changes in the renal allograft, we have analyzed 444 consecutive renal allograft biopsies from the first 90 days posttransplant. Moderate or severe glomerulitis occurred in 13.5% of the biopsies. There was a strong tendency toward clustering of glomerulitis: if one biopsy from a patient had glomerulitis, there was a high probability that it occurred in other biopsies from the same patient. There was some correlation with conventional acute rejection, but 40% of all biopsies with glomerulitis had no rejection and 53% of all biopsies with rejection had no glomerulitis. Graft function at biopsy was nil or decreased in many patients, but this could largely be explained by the independent presence of primary graft dysfunction or conventional rejection, these conditions being a frequent indication for performing a graft biopsy. Moderate or even severe glomerulitis was, however, compatible with a functioning graft. No correlation between glomerulitis and active CMV infection was found. The one-year graft survival of grafts with early posttransplant glomerulitis was 66%. If early conventional acute rejection is taken into consideration, graft survival does not seem to be influenced by the presence of glomerulitis. Early posttransplant endocapillary glomerulitis may be a peculiar pattern of rejection with a pathogenesis different from that of conventional rejection, but the present investigation does not demonstrate any adverse effects on graft function or graft prognosis.

Atubular glomeruli in chronic renal disease

The pathological changes in chronic renal failure are heterogeneous and may depend on the primary disease process. Renal function is better correlated with tubular and interstitial changes than with glomerular changes detectable in simple two-dimensional sections. Atubular glomeruli have been demonstrated in many tubulointerstitial disorders. They constitute a significant portion of the glomerular population in some chronic renal diseases. The atubular glomeruli are generally small, but they have open capillaries and minor ultrastructural changes. The number of capillaries is decreased. Glomeruli connected to normal proximal tubules have volumes at the normal level or above. They have not been shown to be eliminated. The presence of atubular glomeruli may explain the correlation between the volume of proximal tubules and the volume of interstitium, on the one hand, and altered renal function on the other. The presence of atubular glomeruli could explain the irreversibility of chronic renal diseases. It is likely that interstitial fibrosis and tubular atrophy in themselves contribute to the decrease in renal function of both glomerular and nonglomerular renal diseases. In glomerular diseases, the glomerular lesion and hyperfiltration may play the major part in the pathogenesis of the deterioration of renal function. The available evidence points toward glomerulo-tubular disconnection as an important and common cause of progression and irreversibility of chronic renal diseases. It provides a simple explanation for the common observation of severely reduced kidney function and mostly normal-looking glomeruli--at least in two dimensions.

Compensatory growth of glomeruli is accomplished by an increased number of glomerular capillaries

BACKGROUND

The number of glomerular capillaries were unbiasedly estimated in the very heterogeneous population of glomeruli found in rats with lithium-induced nephropathy. The glomeruli are atubular, connected to atrophic tubules, or connected to normal proximal tubules. In rats with lithium nephropathy, hypertrophy is found in glomeruli with normal tubular connection. This hypertrophy may take place by an increase in the number, length, or diameter of the capillaries.

EXPERIMENTAL DESIGN

In serial sections, the glomeruli were sampled at random and followed to detect whether they were connected to an atrophic tubule, a normal proximal tubule, or no tubule at all. On 1-micron-thick serial sections, the number of capillaries was estimated using a method based on a topologic definition of the capillary. The number was estimated for three categories of glomeruli: normal glomeruli from control animals, hypertrophic glomeruli connected to normal proximal tubules from lithium-treated animals, and atrophic glomeruli being either atubular or connected to atrophic tubules from lithium-treated animals. On the same sections, stereologic methods were used to estimate the cross-sectional area and the length density of the glomerular capillaries.

RESULTS

The mean number of capillaries in normal, hypertrophic, and atrophic glomeruli was 188 +/- 26 (+/- SD), 271 +/- 32 (+44%), and 65 +/- 12 (-65%), respectively. Whereas the total length of the capillaries per glomerulus was increased in hypertrophic glomeruli and decreased in atrophic glomeruli compared to normal glomeruli, the mean capillary length of 48.3 +/- 3.7 microns, and 53.0 +/- 11.3 microns in the hypertrophic and atrophic glomeruli, respectively, was significantly higher than the 41.0 +/- 4.6 microns in the controls.

CONCLUSIONS

We conclude that in lithium-induced nephropathy, glomerular hypertrophy is mainly due to the increased numbers of capillaries, whereas the increase in the individual capillary length is of lesser importance.