Severity of tubulointerstitial inflammation and prognosis in immunoglobulin A nephropathy.

Many risk factors for progression in immunoglobulin A nephropathy (IgAN) have been found. We focused on renal leukocyte infiltrations and cytokines in IgAN. The subjects were 204 IgAN patients. Renal histopathological changes were semiquantitatively graded. Expression of tubulointerstitial Leukocyte common antigen (LCA), CD3, CD68, interleukin (IL)-1beta, and IL-10 was evaluated by immunohistochemistry. These parameters were correlated with progression of IgAN. The significance of these correlations was tested by a multivariate analysis. Glomerulosclerosis, tubular atrophy, interstitial inflammation, and hyaline arteriolosclerosis correlated with progression in all patients and also in patients with initially normal serum creatinine. Tubulointerstitial LCA, CD3, CD68, and IL-1beta expression correlated with progression. CD3 had the strongest correlation. In the multivariate analysis, tubulointerstitial CD3, hypertriglyceridemia, elevated serum creatinine concentration, and interstitial fibrosis were independently associated with progressive disease in all patients, and tubulointerstitial CD3 expression and hyaline arteriolosclerosis in patients with initially normal serum creatinine. We found parameters reflecting tubulointerstitial inflammation to predict deterioration of renal function in IgAN. This was also seen in patients whose serum creatinine was normal at the time of renal biopsy. Our findings show that, an immunohistochemical evaluation of tubulointerstitial inflammation seems to be a useful tool in determining the prognosis in IgAN.

Identification of germline MLH1 alterations in familial prostate cancer.

Several linkage and loss of heterozygosity (LOH) analyses suggest that the region 3p21-p26, which is a chromosomal location of MLH1, could harbour a susceptibility gene for prostate cancer (PRCA). Furthermore, in a recent candidate single nucleotide polymorphism (SNP) analysis the I219V variation of the MLH1 gene was associated with PRCA. Microsatellite instability (MSI) and germ-line MLH1 mutations were originally demonstrated in hereditary non-polyposis colorectal cancer (HNPCC) but MSI and loss of MLH1 function have also been detected in PRCA. To assess the contribution of MLH1 germline mutations to the development of PRCA in Finland different approaches were used. First, the samples from 11 PRCA-colon cancer patients were screened for MLH1, MSH2 and MSH6 protein expression by immunohistochemistry (IHC). IHC revealed one patient with a putative MLH1 aberration and sequencing of this sample revealed five sequence variants including two missense variants P434L and I219V. Second, the samples from Finnish hereditary prostate cancer (HPC) families were used for the screening of MLH1 mutations which produced twelve MLH1 sequence variants including two missense mutations, I219V, as in the PRCA-colon cancer patient, and V647M. P434L and V647 were both novel, rare variants. Carrier frequencies of the I219V mutation were compared between hereditary prostate cancer (HPC) patients, unselected PRCA cases, patients with benign prostate hyperplasia and controls, but no differences between the sample groups were found. P434L was not present in this study population and V647M was a very rare variant found only in one HPC family. According to the present results, MLH1 does not have a major role in PRCA causation in Finland.

Androgen receptor alterations in prostate cancer relapsed during a combined androgen blockade by orchiectomy and bicalutamide.

Mechanisms of prostate cancer (CaP) recurrence during a combined androgen blockade (CAB) are poorly understood. Previously, the role of androgen receptor (AR) gene mutations underlying the CAB therapy relapse has been raised. To investigate the hypothesis that AR gene aberrations are involved in CAB relapse, 11 locally recurrent CaP samples from patients treated with orchiectomy and bicalutamide were analyzed for copy number changes and DNA sequence alterations of the AR gene by fluorescence in situ hybridization and single-strand conformation polymorphism, respectively. Altogether, base changes were detected in four tumors (36%). Three of them were missense mutations (G166S, W741C, M749I) and two were silent polymorphisms. Interestingly, none of the tumors had AR amplification. These data suggest that different AR variants are developed and selected for during various types of hormonal treatments, and also, that CAB achieved by orchiectomy and bicalutamide does not act as a selective force for AR amplification.

Association of E-cadherin germ-line alterations with prostate cancer.

In our recent cancer registry-based study, the incidence of gastric carcinoma was increased up to 5-fold in male relatives of early-onset prostate cancer (PCA) patients. This association may reflect the influence of genetic factors predisposing individuals to both tumor types. Germ-line mutations of the CDH1 gene at 16q have recently been associated with familial gastric cancer. Furthermore, two genome-wide linkage studies of PCA recently reported positivity at 16q. We therefore identified families and individual patients with both gastric and PCA and investigated whether the CDH1 gene mutations were involved in cancer predisposition in these cases. Fifteen of the 180 Finnish hereditary PCA families (8.3%) had one or more gastric cancer cases. No truncating or splice site CDH1 mutations were identified by PCR single-strand conformational polymorphism in these families or in eight individual patients who had both prostate and gastric cancer. However, a novel S270A missense mutation in exon 6 of the CDH1 gene was seen in a single family with four prostate and two gastric cancers. A large-scale population-based survey indicated a higher prevalence of S270A among both familial PCA cases (3.3%; n = 120; P = 0.01) and unselected PCA patients (1.5%; n = 472; P = 0.12) as compared with blood donors serving as population controls (0.5%; n = 923). We conclude that individual rare mutations and polymorphisms in the CDH1 gene, such as S270A, may contribute to the onset of PCA and warrant further investigations in other populations. However, the CDH1 gene does not appear to explain the link between prostate and gastric cancer.

Genetic changes in familial prostate cancer by comparative genomic hybridization.

BACKGROUND: Germline mutations in recessive cancer predisposition genes are uncovered by somatic genetic deletions during tumor development. Analysis of genetic changes in tumor tissues from patients with an inherited predisposition may therefore highlight regions of the genome containing susceptibility or modifier genes. Our aim was to characterize genetic changes in familial prostate cancer METHODS: Twenty-one primary prostate cancers from 19 Finnish prostate cancer families were analyzed for somatic genetic changes by comparative genomic hybridization (CGH). RESULTS: The average number of genetic alterations per tumor was 4.0 +/- 1.9, distributed equally among losses and gains. The most common losses were found at chromosomal regions 13q14-q22 (29%), 8p12-pter (24%), and 6q13-q16 (14%), and the most common gains at 19p (25%), 19q (14%) and 7q (14%). CONCLUSIONS: These results suggest that prostate cancers in genetically predisposed individuals arise for the most part through similar somatic genetic progression pathways as sporadic prostate cancers. This also implies that the biological properties of tumors from the two groups may not be different from one another.

Identification of differentially expressed genes in human gliomas by DNA microarray and tissue chip techniques.

New genomic large-scale screening techniques have made the task of establishing an accurate molecular fingerprint of cancer cells feasible. Here, we have used a two-phase strategy for identification of molecular alterations in gliomas. First, cDNA microarrays (Clontech Laboratories, Inc., Research Genetics) were used to pinpoint differentially expressed genes between normal brain and diffuse astrocytomas (grades II-IV), and between a primary tumor and a later tumor reoccurrence in the same patient. More than 200 gene expression alterations were detected from glioblastomas, whereas relatively few changes were seen in grade II and grade III tumors. The most distinct progression-related expression change was the up-regulation of the insulin-like growth factor binding protein 2 (IGFBP2) gene. Second, a high-density tissue microarray of 418 brain tumors was constructed and used for clinical validation of gene expression changes. Strong expression of IGFBP2 was associated with progression and poor patient survival in diffuse astrocytomas (P < 0.0001). Third, comparisons of the data between (a) multiple spots retrieved from one predefined tumor region (IGFBP2 and vimentin immunohistochemistry, 20 tumors) or between (b) standard slides and arrayed tissues (p53 immunohistochemistry, 42 tumors) revealed very little variation. In conclusion, the combined use of DNA microarrays and tissue microarrays offers a powerful strategy for rapid identification and thorough characterization of differentially expressed genes in gliomas.

Grading of diffusely infiltrating astrocytomas by quantitative histopathology, cell proliferation and image cytometric DNA analysis. Comparison of 133 tumours in the context of the WHO 1979 and WHO 1993 grading schemes.

The aim of the study was to evaluate the applicability of quantitative histopathology as an aid for grading diffusely infiltrating astrocytomas. Primary astrocytomas were analysed for parameters (mean nuclear size, mitosis count, area fraction of endothelial cells and tumour necrosis, area fraction of nuclei, and Ki-67 (MIB-1) labelling index), which are closely related to the World Health Organization (WHO) 1979 and WHO 1993 grading criteria. All estimates correlated with the WHO histopathological grade and patient outcome. According to the receiver-operating characteristics curve, the presence of tumour necrosis and mitosis count (cut-off at 3 mitoses/mm2 of neoplastic tissue) showed the best sensitivity and specificity in separating patients with different survival. The multivariate survival analyses confirmed this result. A decision-tree model was constructed based on these two variables: twig I with less than 3 mitoses/mm2, twig II with equal or more than 3 mitoses/mm2 but no necrosis, and twig III with tumour necrosis. This model was found to be more strongly associated with survival than the WHO 1979 or WHO 1993 grading schemes. Low-malignancy astrocytomas (WHO grade II or twig I tumours) could be further divided into two prognostic categories by the image cytometric DNA analysis. The results put an emphasis on astrocytoma grading on mitosis counts (grade II vs. III) and tumour necrosis (grade III vs. IV). To standardize the sampling for mitosis counting, it is suggested that a parallel Ki-67 immunostaining be used for the identification of the most proliferative areas.

Androgen receptor gene amplification increases tissue PSA protein expression in hormone-refractory prostate carcinoma.

Androgen receptor (AR) gene amplification was analysed by fluorescence in situ hybridization (FISH) from 24 paraffin-embedded prostate carcinoma samples recurring locally during hormonal therapy and prostate-specific antigen (PSA) expression from 15/24 of these samples was studied by immunohistochemistry (IHC). AR gene amplification was detected in 29 per cent (7/24) of the recurrent tumours. Using modified Histoscore (MHS), PSA immunostaining in the AR gene-amplified tumours (133+/-102) was twice as high (p=0.054) as in tumours with no amplification (66+/-79) and a statistically significant (p=0.026) association between AR gene amplification and PSA positivity was found when MHS>/=20 was considered positive for PSA. AR gene copy number was positively correlated with PSA MHS in the AR gene-amplified tumours (r=0.893, p=0.012). Histological grade, Gleason's score, and tumour stage did not differ significantly between patients with and without AR gene amplification. In conclusion, these results indicate that AR gene amplification leads to up-regulation of PSA gene (and possibly other androgen-dependent genes), and that patients with AR gene amplification may have elevated serum PSA concentrations without a clear correlation with actual tumour burden.

Cyclin D1 expression in astrocytomas is associated with cell proliferation activity and patient prognosis.

An important positive regulator of the cell cycle, cyclin D1, is often amplified and overexpressed in malignancies. Cyclin D1 aberrations were analysed in grade II-IV astrocytomas by fluorescence in situ hybridization (FISH), mRNA in situ hybridization and immunohistochemistry. Proliferation activity was determined by Ki-67(MIB-1) immunolabelling and mitotic counting. High cyclin D1 expression was observed in grade IV astrocytomas (grades II-III versus grade IV; mRNA expression: p<0.001; immunoexpression: p=0.013), and correlated with poor patient survival (p<0.001, n=46). Upregulated cyclin D1 expression was also closely associated with poor patient prognosis in grade II-III astrocytomas (p<0.001, n=30). Cyclin D1 gene was not found to be amplified (n=7). Cell proliferation activity was significantly increased in tumours exhibiting high cyclin D1 mRNA levels (Ki-67(MIB-1): p<0.001; mitotic count: p<0.001) and high cyclin D1 protein expression (Ki-67(MIB-1): p=0.002; mitotic count: p=0.012). These results indicate that increased production of cyclin D1 is closely associated with high cell proliferation activity and aggressive behaviour in diffusely infiltrating astrocytomas.

Cytoplasmic accumulation of alpha-catenin is associated with aggressive features in laryngeal squamous-cell carcinoma.

Aberrations in the function of alpha-catenin (alpha-cat), the anchoring protein of E-cadherin, are believed to cause dysfunction of the cadherin-catenin complex, leading to disturbed cell-cell adhesion. It has been suggested that expression of alpha-cat in human tumours might be a better indicator of aggressive phenotype than expression of E-cadherin. The value of alpha-cat as a prognostic marker in laryngeal squamous cell carcinoma (LSCC) is unclear. To determine the potential prognostic significance of alpha-cat, paraffin-embedded samples from 159 patients with invasive carcinoma left in the section and with long-term follow-up were evaluated immuno-histochemically for alpha-cat expression, and the results were related to histopathological grade, tumour stage and survival. Two patterns of staining were observed: pure membranous staining (57%) and membranous staining with cytoplasmic involvement (43%). Cytoplasmic involvement of alpha-cat was associated with dedifferentiation, advanced tumour stage and nodal status. In addition, supra-glottic tumours showed more often cytoplasmic involvement of alpha-cat than glottic tumours. Patients with cytoplasmic involvement appeared to have a trend towards poor overall survival, though without statistical significance. These results suggest that cytoplasmic involvement of alpha-cat is associated with aggressive behaviour and metastatic phenotype of LSCC.

Age-related appearance of amyloid P component in human renal glomeruli.

Amyloid P component (AP) is a matrix glycoprotein of adult renal glomeruli. To establish whether the deposition of AP in glomeruli is an age-related phenomenon, this study used indirect immunofluorescence (IF) to investigate 34 renal biopsy specimens and 11 renal autopsy specimens. The biopsy specimens were taken from 9 patients (age range from 2 to 38 years) with normal glomerular morphology and from 25 patients (age range from 4 to 56 years) with various renal diseases. All autopsy specimens (age range form 2 months to 28 years) showed normal glomerular morphology. AP was not detected in glomeruli before age 6. By age 14, the IF intensity reached the level of the adult specimens, in which a strong fluorescence was seen along the basement membranes and within the mesangial matrix. In renal diseases, glomerular AP also appeared after age 6, although varying in its location and intensity. In conclusion, our results indicate that the appearance of AP in glomeruli is an age-related phenomenon, the pattern of which varies in renal diseases.

Reduced E-cadherin expression is associated with invasiveness and unfavorable prognosis in breast cancer.

E-cadherin (E-cad) is a calcium-dependent, epithelial cell adhesion molecule whose reduced or lost expression has been associated with tumor dedifferentiation and increased metastatic potential in human carcinomas. The authors studied immunohistochemically E-cad expression in frozen sections of 362 breast carcinomas using a monoclonal antibody (HECD-1). The immunohistochemical detection of reduced E-cad expression was confirmed by mRNA in situ hybridization with two different oligonucleotide probes. THe proportion of tumors with reduced or lost E-cad expression increased significantly from pure intraductal carcinomas (20%, 4 of 20) through invasive ductal (IDCs; 52%, 124 of 239) to recurrent carcinomas (64%, 18 of 28; chi square test for trend, P = .004). Invasive lobular carcinomas (ILCs) and IDCs differed from each other in their E-cad expression. None of the ILCs (n=55) retained normal E-cad expression in contrast to 48% (115 of 239) of the IDCs. In 259 primary IDCs, reduced E-cad expression was associated with high histologic grade (chi square test for trend, P < .001), negative estrogen receptor status (ER; Fisher's exact test; P = .042), and marginally with axillary node involvement (Fisher's exact test, P = .063). In a subset of 109 primary IDC patients whose clinical follow-up was available (median follow-up 51 months), reduced E-cad expression was associated with shortened disease-free survival (DFS; Mantel-Cox test, P = .027). In Cox's multivariate regression analysis, progesterone receptor status (P = .018) and E-cad expression (P = .072) were selected as independent predictors of DFS. Our findings provide clinical evidence that loss of normal E-cad expression is an indicator of increased invasiveness and dedifferentiation in breast carcinoma. E-cad is a potentially important prognostic factor in primary IDCs.

Comparison of different immunohistochemical methods in the assessment of angiogenesis: lack of prognostic value in a group of 77 selected node-negative breast carcinomas.

There is evidence that tumor angiogenesis, as detected by immunohistochemical staining of endothelium, is of prognostic significance in breast cancer. However, little attention has been paid to possible differences between antibodies or to quantitation of the stained microvessels. We compared three endothelial cell antibodies [anti-human von Willebrand factor (anti-VWF, also termed factor VIII), anti-CD31, and anti-CD34] in archival paraffin-embedded specimens. Anti-CD34 and anti-VWF showed better staining performances than anti-CD31, although the staining results with different antibodies were comparable. Two different methods of microvessel quantitation (the highest microvessel count and percentage microvessel area) were evaluated and also showed significant correlation. From a retrospective database (n = 1000), 77 axillary node-negative invasive ductal breast carcinomas were selected on the basis of clinical outcome to maximize the prognostic power of the sample set (37 died due to a metastatic breast carcinoma, 40 showed no recurrence during 8-yr follow-up). Microvessel quantitations were related to flow cytometric DNA ploidy, c-erb-B-2 overexpression, and estrogen receptor status of the tumor. Surprisingly, neither highest microvessel counts nor microvessel area measurements quantitated with anti-CD34 or anti-VWF immunohistochemistry were able to discriminate between favorable and unfavorable outcome patients. Thus, our results suggest that further evidence is still needed on tumor angiogenesis immunohistochemistry before it can be adopted as a prognostic marker in routine, clinical practice.

Occurrence of late specific complications in type II (non-insulin-dependent) diabetes mellitus.

The objective of the present study was to determine the occurrence of late specific complications, i.e., nephropathy, retinopathy, and autonomic neuropathy, in type II (non-insulin-dependent) diabetic subjects with a recent onset and with a disease duration of at least 5 years. The study design comprised of a population-based controlled cross-sectional survey of middle-aged type II diabetic subjects in the City of Tampere, Southwest Finland. The mean (SD) albumin excretion rate per 24 h was found to have increased in recently diagnosed diabetic subjects, i.e., 54 (111) mg (p < 0.0001), and in long-term diabetic subjects, 134 (479) mg (p < 0.0001), compared to nondiabetic controls, 16 (19) mg. Microalbuminuria (30 mg/24 h < or = albumin excretion rate < or = 300 mg/24 h) was detected in 8% of nondiabetic subjects and in 29% of recently diagnosed subjects and 27% of long-term diabetic subjects. The prevalence of clinical nephropathy (albumin excretion rate > 300 mg/24 h) was 7% in long-term and 4% in recently diagnosed diabetic subjects and zero in nondiabetic subjects. The differences between diabetic and nondiabetic subjects tested for microalbuminuria and clinical nephropathy were significant (p = 0.02-0.0001) exempting the difference between recently diagnosed female diabetic subjects and nondiabetic female subjects tested for clinical nephropathy. Seventy-five percent of biopsied diabetic subjects with an albumin excretion rate exceeding 100 mg/24 h were found to have diabetic glomerulosclerosis, while the rest had a normal finding. In long-term diabetic subjects the prevalence of nonspecific, background and proliferative retinopathies were present in 40%, 31%, and 8%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Renal biopsy findings and clinicopathologic correlations in rheumatoid arthritis.

OBJECTIVE: To evaluate renal biopsy findings and clinicopathologic correlations in patients with rheumatoid arthritis (RA). METHODS: Retrospective study of renal biopsy specimens from 110 RA patients in whom the clinical renal disease was probably due to RA itself and/or to antirheumatic therapy. RESULTS: The most common histopathologic finding was mesangial glomerulonephritis (GN) (n = 40), followed by amyloidosis (n = 33), membranous GN (n = 19), focal proliferative GN (n = 4), minimal-change nephropathy (n = 3), and acute interstitial nephritis (n = 1). Amyloidosis was the most common finding in patients with the nephrotic syndrome. In patients with isolated proteinuria, amyloidosis, membranous GN, and mesangial GN were almost equally common. Although mesangial GN was found in almost two-thirds of the RA patients with hematuria (with or without proteinuria), there still remained a 1 in 5 chance that the biopsy would reveal membranous GN or amyloidosis. Membranous GN was closely related to gold or D-penicillamine therapies, whereas mesangial GN probably related to RA itself. CONCLUSION: The renal morphologic lesion in RA patients with isolated proteinuria and those with hematuria cannot be accurately predicted on the basis of clinical symptoms and signs. Biopsy is thus useful in differential diagnosis, assessment of prognosis, and decision-making with regard to treatment.

Prognostication of astrocytoma patient survival by Ki-67 (MIB-1), PCNA, and S-phase fraction using archival paraffin-embedded samples.

The prognostic power of three proliferation estimation methods, Ki-67 (MIB-1) and PCNA immunohistochemistry, and flow cytometry (S-phase and S + G2/M fractions, respectively), were evaluated in 50 cases of astrocytoma. Each proliferation index showed a strong association with the grade of malignancy (grades I-IV). The MIB-1 labelling index (LI) provided additional information, as it could be used for the discrimination of grade II and grade III astrocytomas (P = 0.0357). All three proliferation estimation methods also had strong prognostic potential (MIB-1 LI: P < 0.0001; PCNA Li: P < 0.0001; S-phase: P = 0.0004; S + G2/M: P = 0.0124). According to the receiver operating characteristics (ROC) curve, the MIB-1 LI showed generally the best sensitivity and specificity in placing the patients correctly into groups of survivors and non-survivors, which was further confirmed in the multivariate analysis. Only 4 per cent of the patients having high MIB-1 scores (> 15.3 per cent) were alive after 2-years' follow-up. In contrast, 72 per cent of patients with tumours of low proliferation activity survived. It appears that Ki-67 (MIB-1) immunolabelling using archival paraffin-embedded samples is of value in predicting prognosis in astrocytic tumours.

Prognostic value of cells with more than 5c DNA content in node-negative breast cancer as determined by image cytometry from tissue sections.

The aim of this investigation was to study the prognostic significance of 5c cells (presence of cancer cells with > 5c DNA content; ie, over 18 pg of DNA per nucleus) in axillary node-negative breast cancer. Tissue sections (3 microns) from 134 tumors were stained for DNA using the Feulgen method and screened for the percentage of 5c cells with the CAS 200 image analysis system (Cell Analysis System, Inc, Lombard, IL). Cancer cells with a DNA content exceeding the 5c level were found in 45% (60 of 134) of the cases, accounting for a median of 0.2% (range, 0.05% to 1.05%) of all cells. The presence of 5c cells was associated with a high histologic grade of the tumor (P = .0001), a large number of mitoses (P < .0001), flow cytometric DNA aneuploidy and high S-phase fraction (P = .0002 and P < .0001, respectively), and c-erbB-2 oncoprotein and p53 tumor suppressor gene product overexpression (P = .0002 and P = .0006, respectively). Patients with 5c cell-positive tumors had a significantly worse 8-year survival rate (P = .003) than those with 5c cell-negative tumors. Subgroup analysis showed that the presence of 5c cells had a prognostic impact in low malignancy tumors, ie, in well-differentiated (grade I or II) and slowly proliferating tumors. Our findings suggest that determination of 5c cells may be a useful additional prognostic factor in axillary node-negative breast cancer. It adds prognostic information, especially in cases that are otherwise thought to have a favorable course.

Comparison of three quantitation methods for PCNA immunostaining: applicability and relation to survival in 83 astrocytic neoplasms.

Recent studies on astrocytic tumours demonstrated a close association between patient prognosis and neoplastic proliferation estimated by such methods as Ki-67 and bromodeoxyuridine labelling. Novel monoclonal PCNA antibodies and special antigen-retrieval techniques have the advantage of working on routinely fixed and embedded specimens and thus make the estimation of proliferation simpler. In addition to PCNA-positive cell count expressed in percentages (PCNA-LI), we estimated the number of PCNA-immunopositive cells count expressed in percentages (PCNA-LI), we estimated the number of PCNA-immunopositive cells of 83 astrocytomas in two ways: (1) per mm2 of neoplastic tissue (uncorrected PCNA index); and (2) per mm2 of total neoplastic nuclear area (corrected PCNA index). Both of these methods were reproducible and showed a good correlation with PCNA-LI and malignancy grade (I-IV). With quantitation methods 1 and 2, the proliferative status of about 2000 cells could be estimated in about 7-10 min, whereas the PCNA count by PCNA-LI of 200 cells took approximately the same time. The proliferation indices obtained by all three quantitation methods were highly significantly related to patient prognosis. The corrected PCNA index, having a close association with the neoplastic cellularity, even divided the glioblastoma group (grade IV) into two significantly different prognostic groups in which 56 and 17 per cent of the patients were alive after 1-year follow-up. The combination of PCNA immunohistochemistry and morphometry seems to give important prognostic information about astrocytomas independent of the histopathological grade.

Intratumor variation in cell proliferation in breast carcinoma as determined by antiproliferating cell nuclear antigen monoclonal antibody and automated image analysis.

Immunohistochemical detection of the proliferating cell nuclear antigen (PCNA) represents a potentially useful tool for the study of tumor proliferative activity. To study the intratumor heterogeneity of tumor growth, 88 breast carcinomas were immunostained with the anti-PCNA antibody 19F4 and analyzed with the CAS 200 image analysis system (Cell Analysis System, Inc., Lombard, IL). For each sample, 12 fields from both the central and the peripheral areas of the tumor were measured. The proportion of PCNA-positive nuclear area in the whole tumor (PCNAt score) varied from 0.7% to 45.2% (median, 14.4%). There was considerable intratumor heterogeneity in the staining for PCNA. In 79% of the specimens, the PCNA score was higher in peripheral areas than in the center of the tumor, the average difference being +3.4% (range, -9.2- +15.1%; P < 0.0001, Student's t-test). The S-phase fraction, determined by DNA flow cytometry of the same tumors, varied from 2.0% to 32.6% (median, 10.0%). The PCNA score showed a significant correlation with the S-phase fraction (r = 0.469, P < 0.001). Most divergent results were those with high PCNA scores and low S-phase fraction; possible explanations for this are discussed. The PCNA score also was related to the histologic grade of the tumors (P = 0.03, analysis of variance). In conclusion, proliferation indices obtained from different areas of a tumor can differ significantly because of intratumor heterogeneity in growth fractions. The PCNA immunostaining correlates with well-known prognostic factors (S-phase fraction and histologic tumor grade) in breast carcinoma.

IgA-IgM nephropathy. A subgroup of primary mesangial glomerulonephritis.

The renal biopsy material of Tampere University Central Hospital comprises 1992 renal biopsy specimens, accessioned during the years 1978-1989. Among these, there were three cases of mesangial glomerulonephritis with a peculiar type of immunofluorescent reactivity. Striking mesangial deposits of both IgA and IgM were found in glomeruli, whereas C3 deposits were absent or present in slight amounts. The light microscopic findings ranged from mild mesangial glomerulonephritis to more advanced forms of sclerosing glomerulopathy. Electron microscopic examination disclosed an increase of mesangial matrix, together with mesangial and paramesangial electron-dense deposits. Two of the patients had microscopic hematuria associated with proteinuria, and one had isolated proteinuria. The authors propose that this group of cases may represent a new subgroup of primary mesangial glomerulonephritis that has not been described previously. They differ immunohistologically from both IgA nephropathy and IgM nephropathy, and therefore could be designated as IgA-IgM nephropathy.