Cardiac 123I-MIBG normal uptake values are population-specific: Results from a cohort of controls over 60 years of age.

PURPOSE: Cardiac 123I-MIBG image interpretation is affected by population differences and technical factors. We recruited older adults without cognitive decline and compared their cardiac MIBG uptake with results from the literature. METHODS: Phantom calibration confirmed that cardiac uptake results from Japan could be applied to our center. We recruited 31 controls, 17 individuals with dementia with Lewy bodies (DLB) and 15 with Alzheimer's disease (AD). Images were acquired 20 minutes and four hours after injection using Siemens cameras with medium-energy low-penetration (MELP) collimators. Local normal heart-to-mediastinum (HMR) ratios were compared to Japanese results. RESULTS: Siemens gamma cameras with MELP collimators should give HMRs very close to the calibrated values used in Japan. However, our cut-offs with controls were lower at 2.07 for early and 1.86 for delayed images. Applying our lower cut-off to the dementia patients may increase the specificity of cardiac MIBG imaging for DLB diagnosis in a UK population without reducing sensitivity. CONCLUSIONS: Our local HMR cut-off values are lower than in Japan, higher than in a large US study but similar to those found in another UK center. UK centers using other cameras and collimators may need to use different cut-offs to apply our results.

123I-MIBG scintigraphy utility and cut-off value in a clinically representative dementia cohort.

OBJECTIVE: To determine the utility of 123I-metaiodobenzylguanidine cardiac scintigraphy (MIBG), and optimum heart: mediastinum ratio (HMR) for differentiating dementia with Lewy bodies (DLB) from Alzheimer's disease (AD) in a clinically representative population, comparing findings with those of 123I-2ß -carbomethoxy-3ß-(4-iodophenyl)-N-(3-fluoropropyl) nortropane (FP-CIT) SPECT. METHODS: We recruited subjects with probable DLB (n = 17) and probable AD (n = 16) from clinical services. Each participant underwent clinical examination, cardiac MIBG scintigraphy and FP-CIT SPECT. Diagnosis was made on the basis of clinical symptoms using validated criteria. Cardiac MIBG uptake was measured by the planar HMR, blind to clinical diagnosis, with values below a cut-off taken from a previous study (<2.2 at four hours) defining scans as abnormal. FP-CIT scans were blindly rated according to a visual rating scale. RESULTS: MIBG had a sensitivity, specificity and overall accuracy of 71%, 81% and 76% for distinguishing DLB from AD. FP-CIT demonstrated a sensitivity, specificity and accuracy of 82%, 88% and 85%. Using a lower HMR cut-off to distinguish between abnormal and normal MIBG scans improved the accuracy of MIBG, raising specificity (100%) and overall accuracy (85%) without compromising sensitivity (71%). Neither prescription of potentially interfering medications, nor a history of myocardial infarction (MI), had a significant effect on HMR. CONCLUSION: We found that MIBG did not demonstrate superior sensitivity and overall accuracy to FP-CIT. HMR cut-off influences biomarker utility, and clinical and Caucasian populations may require a lower cut-off than those reported elsewhere. Future MIBG studies should include clinically representative cohorts as neither medications nor previous MI appear to influence HMR.

Association of endothelial lipase Thr111Ile polymorphism with proliferative retinopathy in type 2 diabetes patients.

AIM: Our previous study demonstrated that the endothelial lipase (EL) C.584C>T polymorphism (rs2000813, p.Thr111Ile) was significantly associated with diabetic retinopathy (DR). The present work was conducted to see if this specific variant of the EL gene was more specifically linked to the severity of DR. METHODS: This retrospective cohort study was based on a review of the institutional charts of 287 type 2 diabetes patients (mean age = 59.7 years; mean BMI = 29.0 kg/m(2); mean HbA1c=8.4%) genotyped for the EL C.584C>T polymorphism (rs2000813, p.Thr111Ile). The stage of DR was also determined for each genotype (CC, CT, TT). RESULTS: On univariate analysis, the minor allele homozygote TT variant was significantly associated with severe DR (OR: 4.3; 95% CI: 1.4, 13.1) compared with the major CC homozygote. No significant result was found for the CT heterozygote. Multivariate analysis revealed an increased risk for TT homozygotes to present with severe non-proliferative DR (OR: 8.09; 95% CI: 1.23, 53.1) or proliferative DR. Other associations were not significant. CONCLUSION: Minor allele homozygosity for this EL variant (c.584C>T) could be a significant risk factor for developing severe, sight-threatening disease due to proliferative DR. Further prospective studies of this EL polymorphism in a larger population sample are needed to confirm these results.

Evaluation of the training and support received by facilitators of a cancer education and support programme in New Zealand.

This study evaluates the training and support provided for facilitators who deliver the Living Well programme. This education and support programme, offered by the Cancer Society of New Zealand since 1991, aims to demystify cancer and its treatments, and develop self-efficacy of cancer patients and their supporters. A purposeful sample of 17 facilitators from five regions across New Zealand participated in semi-structured interviews. Quantitative data on demographics, qualifications and history with the programme were subjected to a frequency analysis. A thematic content analysis was conducted on qualitative data regarding the experiences of the facilitators with the training programme and the level and quality of subsequent support. Facilitators (aged 35-65, 16 of whom were women), came from a variety of socio-economic and educational backgrounds with a significant number having health-related roles and qualifications. Facilitator training was seen as relevant, thorough, effective and good preparation for the demands of the role. The pairing of more experienced staff and volunteers to co-facilitate was a particularly successful aspect of the programme. The main drawbacks were limited access to support, lack of supervision and a perceived lack of appreciation from the organisation for the volunteer facilitators.

Association of endothelial lipase Thr111Ile polymorphism with lipid metabolism and microvascular complications in type 2 diabetic patients.

AIM: Endothelial lipase (EL) is a key enzyme in lipid metabolism, and a polymorphism in the EL gene may be a candidate for modulating lipid parameters in type 2 diabetic (T2D) patients. METHODS: In 396 T2D patients (age: 59.5 ± 10.7 years; BMI: 28.9 ± 5.3 kg/m(2); HbA(1c): 8.2 ± 1.9%), the c.584C>T polymorphism (rs2000813, p.Thr111Ile) was studied in 225 men (frequency of c.584T: 0.351) and 171 women (frequency of c.584T: 0.304). Patients' metabolic parameters, and macrovascular and microvascular complications, were assessed at baseline and at follow-up (mean: 4.2 years). RESULTS: Patients who were homozygous for the minor allele displayed modestly decreased low-density lipoprotein (LDL) cholesterol and raised apolipoprotein B at baseline, and raised systolic blood pressure and high-density lipoprotein (HDL) cholesterol on follow-up. Homozygosity for the minor allele was significantly associated with frequency of retinopathy (P=0.025), with TT homozygous patients more likely to have diabetic retinopathy (OR: 3.505; 95% CI: 1.491-8.239) both initially and at follow-up. CONCLUSION: The c.584C>T EL polymorphism is associated with a higher risk of diabetic retinopathy that could be linked to modifications in HDL-cholesterol metabolism and blood pressure levels.

Expression of reverse cholesterol transport proteins ATP-binding cassette A1 (ABCA1) and scavenger receptor BI (SR-BI) in the retina and retinal pigment epithelium.

AIMS: Excessive lipid accumulation in Bruch's membrane (BrM) is a hallmark of ageing, the major risk factor for age-related macular degeneration (AMD). Retinal pigment epithelial (RPE) cells may utilise reverse cholesterol transport (RCT) activity to move lipid into BrM, mediated through ATP-binding cassette A1 (ABCA1) and scavenger receptor BI (SR-BI). METHODS: ABCA1 expression was assessed by reverse transcription polymerase chain reaction (RT-PCR) and western blotting of human RPE cell extracts. Lipid transport assays were performed using radiolabelled photoreceptor outer segments (POS). ABCA1 and SR-BI expression was examined in normal mouse eyes by immunofluorescence staining. BrMs of ABCA1 and SR-BI heterozygous mice were examined microscopically. RESULTS: Human RPE cells expressed ABCA1 mRNA and protein. The ABCA1 and SR-BI inhibitor glyburide (also known as glibenclamide) abolished basal transport of POS-derived lipids in RPE cells in the presence of high-density lipoprotein. Mouse retina and RPE expressed ABCA1 and SR-BI. SR-BI was highly expressed in RPE. BrMs were significantly thickened in SR-BI heterozygous mice, but not in ABCA1 heterozygous mice. CONCLUSION: RPE cells express ABCA1 and SR-BI. This implies a significant role for SR-BI and ABCA1 in lipid transport and RCT in the retina and RPE.

High density lipoprotein mediated lipid efflux from retinal pigment epithelial cells in culture.

BACKGROUND/AIM: [corrected] The transport of radiolabelled photoreceptor outer segments (POS) lipids was investigated by cultured retinal pigment epithelial cells (RPE). Phagocytosis of POS by the RPE is essential to maintain the health and function of the photoreceptors in vivo. POS are phagocytised at the apical cell surface of RPE cells. Phagocytised POS lipids may be either recycled to the photoreceptors for reincorporation into new POS or they may be transported to the basolateral surface for efflux into the circulation. RESULTS: The authors have demonstrated that high density lipoprotein (HDL) stimulates efflux of radiolabelled lipids, of POS origin, from the basal surface of RPE cells in culture. Effluxed lipids bind preferentially to HDL species of low and high molecular weight. Effluxed radiolabelled phosphotidyl choline was the major phospholipid bound to HDL, with lesser amounts of phosphatidyl ethanolamine, phosphatidyl inosotol. Effluxed radiolabelled triglycerides, cholesterol, and cholesterol esters also bound to HDL. Lipid free apolipoprotein A-I (apoA-I) and apoA-I containing vesicles also stimulate lipid efflux. CONCLUSION: The findings suggest a role for HDL and apoA-I in regulating lipid and cholesterol transport from RPE cells that may influence the pathological lipid accumulation associated with age related macular degeneration.

Elevated baseline triglyceride levels modulate effects of HMGCoA reductase inhibitors on plasma lipoproteins.

BACKGROUND: The response in levels of very-low-density (VLDL) and low-density (LDL) lipoproteins varies substantially among hyperlipidemic patients during treatment with HMGCoA reductase inhibitors. Apolipoprotein E genotype and gender are known to contribute to the regulation of steady state levels of plasma lipoproteins. This study explores the effect of these and other potential determinants of the response of VLDL and LDL to treatment with reductase inhibitors. METHODS: Using mixed linear statistical models, the response of lipoprotein lipid values was studied in 142 hyperlipidemic individuals who were treated with reductase inhibitors. Patients received one or more of the following drugs individually for a total of 623 treatment observations: lovastatin, pravastatin, simvastatin, or atorvastatin. For evaluation of the effects of treatment in the aggregate, actual doses were expressed as equivalent doses of atorvastatin, using factors based on random assignment comparisons in 16 reported studies. The analysis factors considered were apolipoprotein E genotype, baseline average triglycerides >170 mg/dL (vs less), and gender. RESULTS: Presence of an apo epsilon4 allele was associated with a trend toward greater reduction of triglyceride levels and a diminished ability of the reductase inhibitors to reduce LDL cholesterol levels. Gender had only minimal effect on the response of either LDL cholesterol or triglycerides. However, the effect of elevated baseline triglycerides on the response of both triglycerides and LDL cholesterol was striking and was exerted in opposite directions. The triglyceride-lowering effect of reductase inhibitors was greater in patients with initial triglyceride levels above 170 mg/dL (P=0.0001). The effect was even greater in patients with initial triglyceride levels over 250 mg/dL (P=0.015). Conversely, for LDL cholesterol levels, elevated baseline triglycerides were associated with a significantly decreased response to the drugs (P=0.0015). CONCLUSIONS: These findings indicate that baseline triglyceride levels are an important predictor of response of plasma lipoproteins to HMGCoA reductase inhibitors, perhaps reflecting fundamental differences in mechanism underlying the hyperlipidemic phenotype.

Apolipoprotein L gene family: tissue-specific expression, splicing, promoter regions; discovery of a new gene.

Previously we identified and cloned the cDNA for a new protein, apolipoprotein L (apoL), present in plasma and mainly associated with large high density lipoprotein particles. Using 5' rapid amplification of cDNA ends, RT-PCR and comparison with three Human Genome Project and three expressed sequence tag sequences, we have characterized the gene for apoL and for three additional, highly homologous proteins that constitute a new family of proteins that display no homology with previously described apolipoproteins. The genes for all four proteins, apoL-I, apoL-II, apoL-III, and apoL-IV, are located at chromosome 22q12.1-13.1 within a 127,000-bp region. The apoL-I gene is in the opposite orientation to the other three. All four genes have TATA-less promoters, which contain putative sterol regulatory elements, suggesting that transcription of these genes may be coordinated with that of the low density lipoprotein receptor and genes in pathways involving the synthesis of triglycerides and cholesterol. The gene family has a consensus eight-exon structure with alternative splice sites that could produce as many as eight distinct gene products. The apoL-II and apoL-III genes have alternative transcriptional start sites as a result of additional 5' exons. apoL-I, apoL-II, and apoL-III are expressed to the highest degree in the lung. Other tissues with high expression are the pancreas, prostate, spleen, liver, and placenta. Four clustered common polymorphisms, three of which altered the protein sequence, were found in apoL-I, all in linkage disequilibrium, and describing two haplotypes: the more common Lys166/Ile244/Lys271 and the rarer Glu166/Met244/Arg271.

Haplotypes of the human renin gene associated with essential hypertension and stroke.

The human renin gene (REN) is a good candidate in studies aimed at unravelling the genetic basis of essential hypertension and stroke. We previously established that both a BglI and an MboI dimorphisms (located respectively in the first and ninth introns of the REN gene) were associated with essential hypertension in a population of hyperlipidaemic US subjects. In this association (retrospective case-control) study, we investigated the haplotype distribution of alleles defined by the combination of REN BglI and MboI dimorphic sites in 329 hyperlipidaemic US Caucasian subjects referred to UCSF Medical Center (140 hypertensives, 141 normotensives, and 48 hypertensive patients who had suffered a stroke). A statistically significant association was found between alleles determined by both (BglI(-)/MboI(+)) and (BglI(+)/MboI(+)) haplotypes and clinical diagnosis of EHT (combined odds ratios, OR = 3.35, corrected P < 10(-7)). Haplotypes (-,+) and (+,+) were also found to be associated with clinical diagnosis of stroke (OR = 4.31, P < 10(-7)). These associations do not occur through the effects of classical risk factors related to lipid, lipoprotein and apolipoprotein levels. We conclude that variations of the REN (or of a nearby) gene that may be in linkage disequilibrium with REN (BglI(-)/MboI(+)) and (BglI(+)/MboI(+)) alleles could play a role in contributing to increased individual's genetic susceptibility to EHT and to stroke. Journal of Human Hypertension(2001) 15, 49-55

A risk factor for atherosclerosis: triglyceride-rich lipoproteins.

Compelling evidence from meta-analysis of a number of clinical studies on a large aggregate of patients has established an increased level of triglycerides as an independent risk factor for atherosclerotic heart disease. The finding of triglyceride-rich lipoproteins in human atheromata has provided substantial pathophysiologic evidence for a direct role in atherogenesis. Hypertriglyceridemia is commonly embedded in the context of a metabolic syndrome that includes central obesity, insulin resistance, low levels of HDL cholesterol, and often hypertension. Hypertriglyceridemia also appears to underlie the phenomenon of small dense LDL in most instances. Therapeutic interventions must be directed at underlying obesity, insulin resistance, and diabetes when present, as well as addressing metabolic determinants of dyslipidemia per se. Diet, exercise, weight loss, and avoidance of alcohol are the cornerstones of treatment. The choice of medication should be based on the lipoprotein phenotype. Niacin, fibric acid derivatives, and omega-3 fatty acids are most useful in treating severe hypertriglyceridemia. HMG-CoA reductase inhibitors are useful in some phenotypes with moderately increased triglyceride levels. Evidence from a number of clinical trials indicates that mitigation of risk of coronary heart disease, and possibly stroke, can be effected by reducing levels of plasma triglycerides.

Plasma apolipoprotein L concentrations correlate with plasma triglycerides and cholesterol levels in normolipidemic, hyperlipidemic, and diabetic subjects.

Apolipoprotein L is a newly recognized component of human plasma lipoproteins. Mainly associated with apoA-I-containing lipoproteins, it is a marker of distinct HDL subpopulations. In an effort to gain inference as to its as yet unknown function, we studied biological determinants of apoL levels in human plasma. The distribution of apoL in normal subjects is asymmetric, with marked skewing toward higher values. No difference was found in apoL concentrations between males and females, but we observed an elevation of apoL in primary hypercholesterolemia (10.1 vs. 8.5 microgram/mL in control), in endogenous hypertriglyceridemia (13.8 microgram/mL, P < 0.001), combined hyperlipidemia phenotype (18.7 g/mL, P < 0.0001), and in patients with type II diabetes (16.2 microgram/mL, P < 0.02) who were hyperlipidemic. Significant positive correlations were observed between apoL and the log of plasma triglycerides in normolipidemia (0.446, P < 0.0001), endogenous hypertriglyceridemia (0.435, P < 0.01), primary hypercholesterolemia (0.66, P < 0.02), combined hyperlipidemia (0.396, P < 0.04), hypo-alphalipoproteinemia (0.701, P < 0.005), and type II diabetes with hyperlipidemia (0.602, P < 0. 01). Apolipoprotein L levels were also correlated with total cholesterol in normolipidemia (0.257, P < 0.004), endogenous hypertriglyceridemia (0.446, P = 0.001), and non-insulin-dependent diabetes mellitus (NIDDM) (0.548, P < 0.02). No significant correlation was found between apoL and body mass index, age, sex, HDL-cholesterol or fasting glucose and glycohemoglobin levels. ApoL levels in plasma of patients with primary cholesteryl ester transfer protein deficiency significantly increased (7.1 +/- 0.5 vs. 5.47 +/- 0.27, P < 0.006).

Low levels of high density lipoproteins in Turks, a population with elevated hepatic lipase. High density lipoprotein characterization and gender-specific effects of apolipoprotein e genotype.

Turks have strikingly low levels of high density lipoprotein cholesterol (HDL-C) (10-15 mg/dL lower than those of Americans or Western Europeans) associated with elevated hepatic lipase mass and activity. Here we report that Turks have low levels of high density lipoprotein subclass 2 (HDL(2)), apoA-I-containing lipoproteins (LpA-I), and pre-beta-1 HDL and increased levels of HDL(3) and LpA-I/A-II particles (potentially an atherogenic lipid profile). The frequency distributions of HDL-C and LpA-I levels were skewed toward bimodality in Turkish women but were unimodal in Turkish men. The apoE genotype affected HDL-C and LpA-I levels in women only. In women, but not men, the varepsilon2 allele was strikingly more prevalent in those with the highest levels of HDL-C and LpA-I than in those with the lowest levels. The higher prevalence of the epsilon2 allele in these subgroups of women was not explained by plasma triglyceride levels, total cholesterol levels, age, or body mass index. The modulating effects of apoE isoforms on lipolytic hydrolysis of HDL by hepatic lipase (apoE2 preventing efficient hydrolysis) or on lipoprotein receptor binding (apoE2 interacting poorly with the low density lipoprotein receptors) may account for differences in HDL-C levels in Turkish women (the epsilon2 allele being associated with higher HDL levels). In Turkish men, who have substantially higher levels of hepatic lipase activity than women, the modulating effect of apoE may be overwhelmed. The gender-specific impact of the apoE genotype on HDL-C and LpA-I levels in association with elevated levels of hepatic lipase provides new insights into the metabolism of HDL.

Analysis of hABC1 gene 5' end: additional peptide sequence, promoter region, and four polymorphisms.

Evidence linking mutations in ATP-binding-cassette transporter gene 1 (ABC1) to Tangier disease suggests it functions in the active transport of free cholesterol out of cells. Since its mRNA level is regulated in response to cellular cholesterol stores it is of interest to explore its promoter response elements, and to investigate polymorphisms for their contributions to the prevalence of low levels of HDL in the population that promotes premature coronary heart disease. Investigation of the 5' end of the gene by 5' RACE analysis revealed 455 nucleotides additional to published sequences, and predicts another 60 amino acid N-terminal residues, resulting in a 2261-residue protein. Protein sequence analysis predicts a membrane-spanning region and possible signal peptide. The 5' flanking region was located by a Human Research Project BLAST search. This region contains regulatory elements that potentially control ABC1 gene expression. In addition to numerous SP1 binding sites there are four putative sterol regulatory elements (SREs). Our studies uncovered three single nucleotide substitution polymorphisms, one in the promoter region and two in the 5' untranslated region (5'UTR), plus an insertion/deletion polymorphism.

Lack of association of lipoprotein(a) levels with coronary calcium deposits in asymptomatic postmenopausal women.

OBJECTIVES: This study sought to determine the relationship of lipoprotein(a) (Lp(a)) and other cardiac risk factors to coronary atherosclerosis as measured by calcification of coronary arteries in asymptomatic postmenopausal women. BACKGROUND: Lipoprotein(a) is considered a risk factor for coronary heart disease. Coronary calcium deposition is believed to be a useful noninvasive marker of coronary atherosclerosis in women. However, to our knowledge, there are no reports of the relationship of Lp(a) to coronary calcium in postmenopausal women. METHODS: In 178 asymptomatic postmenopausal women (64 +/- 8 years), we measured Lp(a) and other cardiac risk factors: age, hypertension, diabetes, low-density lipoprotein cholesterol, smoking status, body mass index, physical activity level and duration of hormone replacement therapy. Electron-beam computed tomography was done to measure coronary calcium (calcium score). We analyzed the relationship between calcium score and cardiac risk factors using multivariate analysis. RESULTS: Although calcium score correlated with traditional risk factors of age, diabetes, hypertension and smoking, it did not correlate with Lp(a) in the asymptomatic postmenopausal women. Similar multivariate analyses were done in the subjects age >60 years and in the subjects with significant coronary calcium deposit (calcium score > or =50). These analyses also have failed to show an association of levels of Lp(a) with coronary calcium deposits. CONCLUSIONS: We conclude that in asymptomatic postmenopausal women, Lp(a) levels do not correlate with coronary atherosclerosis as measured by coronary calcium deposits.

Renin gene MboI dimorphism is a discriminator for hypertension in hyperlipidaemic subjects.

As renin is the key enzyme of the renin-angiotensin-aldosterone system, the renin gene (REN) represents a good candidate quantitative trait locus for investigations aimed at uncovering the molecular and genetic influences implicated in the molecular etiology of essential hypertension. Among the various polymorphic markers that are available at the REN gene locus, an MboI dimorphic site located in the ninth intron of the REN gene has previously been shown to be significantly associated with a family history of hypertension in a Japanese population and with direct clinical diagnosis of essential hypertension in a Gulf population. We determined MboI allele and genotype distributions in a sample population of 349 (178 men, 171 women) hyperlipidaemic US Caucasians (mean age 55.4+/-13.1 yr), comprising 122 hypertensive and 227 normotensive subjects. A statistically significant association was found between alleles on which the MboI site was present [MboI(+)] and clinical diagnosis of hypertension. REN MboI(+) alleles are thus in linkage disequilibrium with genetic influences that contribute to increased individual susceptibility to hypertension of hyperlipidaemic patients (with an associated odds ratio of 2.15, 95% CI: 1.34-3.45). This positive association does not seem to occur through the effect of classical risks factors represented by lipid, lipoprotein and apolipoprotein levels.

A multilocus genotyping assay for candidate markers of cardiovascular disease risk.

A number of chronic diseases, including cardiovascular disease, appear to have a multifactorial genetic risk component. Consequently, techniques are needed to facilitate evaluation of complex genetic risk factors in large cohorts. We have designed a prototype assay for genotyping a panel of 35 biallelic sites that represent variation within 15 genes from biochemical pathways implicated in the development and progression of cardiovascular disease. Each DNA sample is amplified using two multiplex polymerase chain reactions, and the alleles are genotyped simultaneously using an array of immobilized, sequence-specific oligonucleotide probes. This multilocus assay was applied to two types of cohorts. Population frequencies for the markers were estimated using 496 unrelated individuals from a family-based cohort, and the observed values were consistent with previous reports. Linkage disequilibrium between consecutive pairs of markers within the apoCIII, LPL, and ELAM genes was also estimated. A preliminary analysis of single and pairwise locus associations with severity of atherosclerosis was performed using a composite cohort of 142 individuals for whom quantitative angiography data were available; evaluation of the potentially interesting associations observed will require analysis of an independent and larger cohort. This assay format provides a research tool for studies of multilocus genetic risk factors in large cardiovascular disease cohorts, and for the subsequent development of diagnostic tests.

Evaluation of Langerhans' cells in the cervical epithelium of women with cervical intraepithelial neoplasia.

OBJECTIVE: Cervical infection with human papillomavirus (HPV) results in a more permissive environment for malignant transformation. In squamous epithelia the Langerhans' cell (LC) is responsible for antigen presentation. Studies that use S-100 immunostaining demonstrate low LCs in cervical intraepithelial neoplasia (CIN) while those that use other methods have shown normal numbers of LCs. This observation led us to postulate that a defect in S-100 proteins, not a simple decrease in LC number, may be the cause of immune suppression. To evaluate this we identified LCs in the cervix of women with HPV/CIN in a prospective fashion using two antibodies, S-100 and CD1, each targeting a different element of the LC. METHODS: Paired biopsies of the cervix were taken, one paraffin embedded for S-100 and the other snap frozen for CD1 staining. LCs were counted and expressed as the number of cells per millimeter of epithelium. Analysis of variance was used to assess differences between counts in normal, low-grade, and high-grade lesions. HPV was tested by hybrid capture. RESULTS: S-100 LCs were significantly reduced in dysplasia, LG 8.6 and HG 6.0, compared to normal at 16.7 cells/mm (P = 0.04). S-100 LCs were reduced in HPV-infected cases at 5.9 vs 12.8 cells/mm in HPV negatives (P = 0.02). Acute inflammatory infiltrates were associated with increased S-100 LCs independent of pathology. CD1 LCs were not significantly altered by any parameters tested. CONCLUSIONS: HPV/CIN may exert an immunosuppressive effect by decreasing the S-100 LCs. The association of S-100-positive LCs coupled with cervical inflammatory changes suggests an important function of the S-100 proteins in the development of an anti-HPV response.

The apolipoprotein B R3531C mutation. Characteristics of 24 subjects from 9 kindreds.

Familial ligand-defective apolipoprotein B (apoB) is a group of disorders caused by mutations in the apoB gene. In this report the R3531C mutation is characterized further using a monoclonal antibody MB19/dynamic laser light scattering technique to measure ratios of Cys(3531) to normal low density lipoprotein (LDL) particles. All six subjects studied showed a preferential accumulation of particles carrying the defective apoB allotype. We determined binding properties of LDL from R3531C heterozygotes by measurement of high-affinity binding to LDL receptors on fibroblasts and its ability promote growth of U937 cells. LDL from R3531C heterozygotes, compared to normal LDL, had 49.3% of the binding affinity and was 74% as effective in a U937 cell proliferation assay. To identify new probands, we screened 2570 subjects for the R3531C mutation. Nine probands were found with 15 affected relatives. Of the seven haplotypes we uncovered, two were novel, while five were identical to one initially reported as associated with Cys3531. Three silent mutations were detected also: T3540T, N3542N and T3552T. Analysis of lipid profiles of R3531C families showed, as with the R3500Q mutation, variable expression of the phenotype, modulated by environmental and other genetic factors. Both mutations tend to produce lower plasma levels of LDL in affected subjects than do defects of the LDL receptor (familial hypercholesterolemia, FH). This study shows that the Cys(3531) LDL particles are not only defective at binding to the LDL receptor, as determined by two separate methods, but that in all cases they accumulate preferentially compared to the normal allotype.-Pullinger, C. R., D. Gaffney, M. M. Gutierrez, M. J. Malloy, V. N. Schumaker, C. J. Packard, and J. P. Kane. Apolipoprotein B R3531C mutation: characteristics of 24 subjects from 9 kindreds. .