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PubMed2003

A longitudinal study of alpha1-antitrypsin phenotypes and decline in FEV1 in a community population.

BACKGROUND: It is well-known that the homozygous deficiency of alpha(1)-antitrypsin, phenotype PiZZ, is associated with an increased risk of COPD. However, studies evaluating the association between the heterozygous forms of the alpha(1)-antitrypsin phenotype PiMZ and rapid decline in lung function, both in patient and community populations, have yielded conflicting results. STUDY OBJECTIVE: To assess the relationship between alpha(1)-antitrypsin phenotypes and decline in FEV(1) values of 2,016 adult subjects in a community population in Tucson, AZ. DESIGN AND METHODS: Prospective cohort study. Standardized questionnaires and lung function measurements were administered 1.5 to 2 years apart during 12 surveys. RESULTS: The frequency distribution for PiMM, PiMS, and PiMZ phenotypes did not differ significantly by physician-confirmed diagnoses of emphysema, chronic bronchitis, or asthma. There was no statistically significant difference in mean FEV(1) slope values between PiMM, PiMS, and PiMZ phenotypes (-22.5, -21, and -7 mL per year, respectively). After controlling for smoking and other potential confounders, the FEV(1) slope was associated with an initial FEV(1) level and age for the initial questionnaire but not with the different phenotypes. Selecting cutoff values, we identified rapidly declining and nondeclining subgroups, based on the percent predicted changes in FEV(1). They also were not associated with alpha(1)-antitrypsin phenotypes. CONCLUSIONS: We conclude that the data from this longitudinal community study suggest that having the PiMZ phenotype is not a significant risk factor for an accelerated decline in FEV(1).

Adult↗
PubMed1988

Apolipoprotein E phenotypes of normo- and hyperlipoproteinemia in Japanese.

Apolipoprotein E phenotypes of normo- and hyperlipoproteinemia in Japanese were examined by the disc gel isoelectric focusing technique, which was modified according to the method of Kashyap et al. (1981). Apoprotein E isoproteins were clearly separated by this method. Six phenotypes (E2/2, E3/3, E4/4, E2/3, E2/4 and E3/4) were determined in 107 cases of normolipoproteinemia and 75 cases of hyperlipoproteinemia. In normolipoproteinemia, apoE phenotype frequencies were similar to those of the Japanese and Caucasian populations which were reported previously. In hyperlipoproteinemia, a higher frequency of phenotype E2/2 and a lower frequency of E3/3 were observed. The apo E phenotypes of type IIa and IIb were distributed similarly to that of normal subjects. In contrast, only 27.8% of type IV patients had E3/3 phenotype. Among type V patients 64.3% was homozygous or heterozygous for E-4, and only 14.3% was homozygous for E-3 (E3/3). The results suggest that the apolipoprotein E phenotypes are similarly distributed among different human races and the apolipoprotein E phenotypes could be one of the etiological factors associated with some types of hyperlipoproteinemia.

Adult↗
PubMed1996

Angiotensin II and calcium blockers prevent glomerular phenotypic changes in remnant kidney model.

Recent studies on various models of glomerular diseases indicate that glomerular injury is associated with the phenotypic modulation of glomerular cells. However, the effect of renoprotective agents on glomerular phenotype remains to be determined. This study examined the effects of angiotensin II Type 1 (AT1) receptor antagonists and calcium antagonists on glomerular phenotypic changes in rats with subtotal renal ablation. Rats were subjected to 5/6 nephrectomy and were given oral TCV-116, a selective AT1 receptor antagonist (1 mg/kg), manidipine, a dihydropyridine calcium antagonist (3 mg/kg), or vehicle for 8 wk. Glomerular phenotypic modulation was determined by the staining of alpha-smooth muscle actin and desmin in glomerular cells with an immunohistochemical technique. At the start of drug treatment, alpha-smooth muscle actin and desmin were already significantly expressed in the glomerular cells of 5/6-nephrectomized rats, in contrast to a negligible glomerular expression of these proteins in sham-operated rats. Treatment of 5/6-nephrectomized rats with TCV-116 or manidipine significantly decreased glomerular expression of alpha-smooth muscle actin and desmin, thereby indicating that these drugs prevented glomerular phenotypic changes in 5/6-nephrectomized rats. Furthermore, their inhibitory effects on glomerular phenotypic modulation were associated with the prevention of glomerular cell proliferation, hypertrophy, and sclerosis. Therefore, this study provides the first evidence that the renoprotection is linked to the prevention of glomerular phenotypic modulation and supports the idea that this phenotypic modulation may serve as an important cellular marker of glomerular injury.

Actins↗
PubMed2003

Characterization and consumer acceptance of three muscles from Hampshire x Rambouillet cross sheep expressing the callipyge phenotype.

Eight Hampshire x Rambouillet crossbred wethers expressing the callipyge phenotype and eight Hampshire x Rambouillet half-sibling wethers with a normal phenotype were slaughtered when they reached 59 kg. The supraspinatus (SPM), longissimus (LM), and semitendinosus (STM) muscles were analyzed to determine callipyge effects on calpain and calpastatin activities, sarcomere length, percentage of muscle fiber types, and muscle fiber areas. After 14 d of aging, chops were frozen until analyses for trained sensory panel evaluations, Warner-Bratzler shear force values, and consumer perceptions of tenderness, flavor, juiciness, and overall satisfaction of chops were conducted. Calpastatin activity was 57% greater (P < 0.05) and m-calpain activity was 33% greater (P < 0.05) in muscles from carcasses of callipyge than normal sheep. Sarcomeres were shorter (P < 0.001) in the LM than the SPM or STM, regardless of phenotype. Muscle fiber area was 76% larger (P < 0.05) in the LM of callipyge than normal sheep, but muscle fiber area was not affected (P > 0.05) by phenotype in the SPM or STM. Phenotype had no effect (P = 0.12) on the percentage of slow-twitch, oxidative fiber types in any of the three muscles. In STM and LM from callipyge lambs, the percentage of fast-twitch, oxidative/glycolytic fibers was lower (P < 0.05) and that of fast-twitch-glycolytic fibers was higher (P < 0.05) than in their normal counterparts. Phenotype did not affect (P = 0.90) the fiber type percentage in the SPM. Callipyge LM were less tender and normal LM were more tender than other chops (P < 0.05). Callipyge loin chops had higher Warner-Bratzler shear force values than other chops (P < 0.001). Consumers rated fewer (P < 0.05) callipyge loin and shoulder chops acceptable in juiciness, tenderness, and overall acceptability than normal chops, but phenotype did not affect (P > 0.05) consumer acceptability of leg chops. These results indicate that LM from Hampshire x Rambouillet sheep displaying the callipyge phenotype had higher calpastatin activity and were less tender than the LM from normal sheep. In addition, consumer perceptions indicated that only one in 10 leg chops, one in five shoulder chops, and one in four loin chops from callipyge sheep were unacceptable.

Animals↗
PubMed1985

Effects of alterations in cell phenotype and hypokalemia on sodium-potassium pump activity in rabbit vascular smooth muscle.

We investigated in cell culture, how alterations in phenotype accompanying proliferation of rabbit aortic smooth muscle and chronic hypokalemia could affect the Na,K pump. Total rubidium-86 uptake as well as ouabain and frusemide-sensitive uptake into cells was measured in physiological salts solution (PSS), PSS containing 5% foetal calf serum and PSS containing foetal calf serum plus 15 microM monensin. In physiological salts solution 90% of the rubidium-86 uptake into contractile or synthetic state cells was frusemide-sensitive and less than 8% ouabain-sensitive. Total and frusemide-sensitive rubidium-86 uptakes, measured in PSS or PSS containing foetal calf serum were similar in cells cultured and maintained in the contractile phenotype, cells in the synthetic phenotype and those which had recently reverted from the synthetic to contractile phenotype. When cells were sodium loaded in the presence of monensin and foetal calf serum, ouabain-sensitive rubidium-86 uptake was 50% higher in cells which were maintained in culture in the contractile phenotype. Frusemide-sensitive rubidium-86 uptake was similar in each cell phenotype. To examine how cell culture in hypokalemic media would affect the Na,K pump, we determined ouabain-sensitive rubidium-86 uptake in the presence of monensin plus foetal calf serum in cells incubated for 24 hours in low and normal potassium containing culture media. Ouabain-sensitive uptake was 20% higher in cells cultured in a 0.76 mM potassium medium than in those cultured in 5.4 mM potassium medium. Frusemide-sensitive rubidium-86 uptake was unaffected. These results demonstrate that 'maximal' Na,K pump activity in sodium-loaded cells is reduced when cells change from the contractile to synthetic phenotype. This reduction appears only very slowly reversible when cells revert from the synthetic to contractile phenotype. Prolonged hypokalemia increases 'maximal' activity of the Na,K pump.

Animals↗
PubMed1999

Nutritional influences on the composition of milk from cows of different protein phenotypes in New Zealand.

The objective of this study was to investigate the effects of contrasting nutritional regimens on milk composition from cows of different protein phenotypes. Twenty sets of seasonally calving identical twin cows that constituted five different protein phenotypes (four sets of twins per phenotype) were subjected to two nutritional treatments in crossover experiments during spring (early lactation) and summer (mid to late lactation). The phenotypes studied allowed a comparison of the AA, AB, and BB variants of both beta-lactoglobulin (beta-LG) and kappa-casein. Nutritional treatments were 1) ad libitum grazing (i.e., cows were allocated a pasture allowance of approximately 40 kg of dry matter/d per cow) plus 5 kg of a concentrate based on barley and 2) restricted grazing (pasture allowance of 20 kg of dry matter/d per cow). Milk samples were collected from each cow near the end of each 14-d treatment period and were analyzed for a detailed range of individual protein and fat constituents. Diet had significant effects on the concentrations of all milk components measured. Protein phenotype affected some protein components but not fat components. Interactions between the effects of beta-LG phenotype and diet were noted for the concentrations of some milk components. Diet and protein phenotype have important effects on the manufacturing potential of milk produced under the dairying systems of New Zealand, which rely heavily on grazing. The effects of nutrition on milk composition may depend on the beta-LG phenotype.

Animal Nutritional Physiological Phenomena↗
PubMed2004

Prevalence of alpha1-antitrypsin phenotypes in patients with IgA nephropathy.

BACKGROUND: alpha1-antitrypsin (AAT) is the main protease inhibitor in the blood. Several different AAT phenotypes exist. The most common variant is the MM phenotype, which is also associated with normal AAT levels. The less common phenotypes with Z and S variants are associated with low AAT levels. AAT deficiency is a risk factor for pulmonary emphysema, liver impairment and some immune-mediated diseases, some of which are also associated with IgA nephropathy (IgAN). In fact, liver impairment resulting from AAT deficiency may directly contribute to renal abnormalities resembling IgAN. PATIENTS AND METHODS: We investigated AAT phenotype and AAT levels in 100 IgAN patients who did not have end-stage liver disease. Fifteen patients in our sample had secondary IgAN. We also tested for the presence of renal deposition of AAT in patients heterozygous for AAT variants as well as in a randomly chosen group of patients with MM phenotype. We checked for any association between AAT phenotype and the progression of IgAN as well as the prevalence of diseases associated with IgAN (i.e. secondary IgAN). RESULTS: Twelve patients in our sample were heterozygous for AAT variants. Phenotypes were MZ in 5 patients, MS in 3, MF in 1, ML in 2 and ME in 1 patient. AAT levels were lower in these 12 patients than in those homozygous for the M variant (1.17+/-0.46 vs. 1.44+/-0.34 g/l, p < 0.05). We found renal deposition of AAT in 2 heterozygous patients and in 1 of the 12 patients which were randomly chosen. End-stage renal (ESRF) failure developed in 3 of the 12 heterozygous patients and in 6 of the 88 homozygous patients (p = 0.07) during the follow-up. The prevalence of heterozygosity was significantly higher in patients with secondary IgAN than in those with primary IgAN ((5/15 vs. 7/85; p < 0.02). CONCLUSIONS: AAT phenotype is not associated with the risk of primary IgA nephropathy, but might have an impact on disease outcome as well as on the risk of secondary IgAN.

Adolescent↗
PubMed2000

Genotypes and phenotypes for apolipoprotein E and Alzheimer disease in the Honolulu-Asia aging study.

BACKGROUND: The utility of apolipoprotein E (ApoE) type as an indicator of genetic susceptibility to Alzheimer disease (AD) depends on the reliability of typing. Although ApoE protein isoform phenotyping is generally assumed equivalent to genotyping from DNA, phenotype-genotype differences have been reported. METHODS: ApoE genotype and phenotype results were examined for 3564 older (ages 71-93 years) Japanese-American male participants of the Honolulu-Asia Aging Study, an ongoing population-based study of aging and dementia. RESULTS: Both methods demonstrated similar associations of ApoE type with AD: a direct association with ApoE4 and a less dramatic inverse association ApoE2. Advanced age did not appear to influence the ApoE4-AD association. The association with AD among ApoE4 homozygotes [odds ratio (OR) = 14.7] was higher than expected based on an observed OR of 2.0 in heterozygotes. Phenotype-genotype nonconcordance was more frequent for ApoE2 than for ApoE4. The ApoE2 phenotype occurred at a frequency of 7.9% vs a genotype frequency of 4.9%, corresponding to a probability of 56% that an individual with ApoE2 phenotype had the same genotype. CONCLUSIONS: Whereas E4 and E2 phenotypes and genotypes were comparably associated with AD, neither method would be expected to substantially improve the efficiency of case finding in the context of population screening beyond prediction based on age and education. Nonconcordance of phenotype and genotype was substantial for E2 and modest for E4 in this population. The ApoE4-AD association was independent of age.

Aged↗
PubMed2002

Apolipoprotein(a) phenotypes predict the severity of coronary artery stenosis.

BACKGROUND: Studies on the impact of elevated levels of lipoprotein(a) (Lp[a]) or apolipoprotein(a) (apo[a]) on the development of coronary artery disease have given controversial results. The relationship between apo(a) phenotypes and coronary artery stenosis remains unclear. METHODS: Lipid profiles, and apo(a) levels and phenotypes were analyzed in 225 patients who underwent elective coronary angiography. Coronary artery stenosis, as indicated by angiography, was estimated by a newly devised minimal lesion (ML) grading system. Relationships between lipoprotein variables and coronary artery stenosis were examined by linear and logistic regression models. RESULTS: On the basis of ML score, patients with larger apo(a) phenotypes (S3, S3a or S4) had a lower rate of coronary artery stenosis (68%-76%) than those with smaller phenotypes (S1, S1a, S2 or S2a - 79%-95%). The odds of coronary artery stenosis in patients with smaller apo(a) phenotypes were significantly different from those of patients with larger phenotypes (p < 0.001). Also, patients with a history of myocardial infarction, angina, hypertension, diabetes or hypercholesterolemia were more likely to show coronary artery stenosis on angiography. With respect to lipid levels, 20.2% of patients had an elevated serum total cholesterol (TC) level and 16.1% an elevated low-density lipoprotein cholesterol (LDL-c) level. In 21.3%, the high-density lipoprotein cholesterol (HDL-c) level was decreased. There were significant positive correlations of serum TC with those of the TC/HDL-c ratio, LDL-c, triglycerides and HDL-c (p < 0.05 and 0.001), of LDL-c with TC and apo(a) (p < 0.001) and of ML scores with the TC/HDL-c ratio and patient age (p < 0.01 and 0.001). There were significant negative correlations of TC and apo(a) levels with apo(a) phenotypes (p < 0.05 and 0.001) and of ML scores with HDL-c (p < 0.001). The odds of coronary artery stenosis in patients with abnormally high apo(a) levels (44.6%) were not significantly different from those of patients with apo(a) levels in the normal range. INTERPRETATION: Smaller apo(a) phenotypes, but not elevated levels of apo(a), may help to predict the rate and severity of coronary artery stenosis. HDL-c independently and negatively correlated with the extent of the stenosis.

Adult↗
PubMed2003

[Clinical phenotypes of classic Rett syndrome].

INTRODUCTION: Rett syndrome (RS) is a progressive neurological disorder that is diagnosed by essential, supportive and exclusion clinical criteria, and development takes place in four stages. It has been shown to be caused by de novo mutations of a gene located in the long arm of the dominant X chromosome that codes for the methyl CpG binding protein (MECP2). It has been observed that girls with classic RS (CRS) present distinguishing nuances with respect to the age of onset of the different criteria and as regards the progression of the disorder. Taking the ability or failure to walk as a reference, we have established three phenotypes. METHOD: Phenotype I. Ambulant CRS, which corresponds to a permanent stage III, or a stage III that lasts a long time before going into stage IV. The loss of the ability to use the hands in a purposeful way takes place at the age of 25.6 months, social withdrawal at 25.4 months, language impairment at 20 months, stereotypic hand movements at 22.8 months and signs of spasticity appear around the age of 8-10 years. Phenotype II. Ambulant CRS. Transitory, which corresponds to an early stage IV-A. The first signs of abnormality appear around the age of 9-10 months. This is followed by the loss of the purposeful use of the hands towards the age of 23.4 months, social withdrawal around 21.4 months, language impairment at 20 months, stereotypic hand movements at 25.2 months and scoliosis, neuromotor disorders and trophic and vasomotor disorders at the age of 4-5 years. Phenotype III. Non ambulant CRS, which corresponds to stage IV-B. It begins with hypotonia towards the age of 5-6 months, loss of voluntary grasping at 17.8 months, social withdrawal at 18 months, language impairment at the age of 12 months, stereotypic hand movements at 13 months and early onset of motor, trophic and vasomotor disorders. Genetic studies were conducted in 12 girls and MECP2 gene mutations were found in 10 of them, belonging to the three different phenotypes. CONCLUSIONS: We have established three phenotypes in RS according to the ability to walk. If walking is not achieved or the ability is lost early on, speech loss, social withdrawal and the onset of stereotypic movements, motor, trophic and vasomotor disorders all progress more quickly. Mutations in the MECP2 gene have been found in the three phenotypes. In 16.6% the genotype was normal. Greater accuracy is required in the definition of cases of CRS in order to establish phenotype genotype correlations.

Child↗
PubMed2003

Relationship of phenotype and genotype in X-linked amelogenesis imperfecta.

X-linked amelogenesis imperfectas (AI) resulting from mutations in the amelogenin gene (AMELX) are phenotypically and genetically diverse. Amelogenin is the predominant matrix protein in developing enamel and is essential for normal enamel formation. To date, 12 allelic AMELX mutations have been described that purportedly result in markedly different expressed amelogenin protein products. We hypothesize that these AMELX gene mutations result in unique and functionally altered amelogenin proteins that are associated with distinct amelogenesis imperfecta phenotypes. The AMELX mutations and associated phenotypes fall generally into three categories. (1) Mutations (e.g., signal peptide mutations) causing a total of loss of amelogenin protein are associated with a primarily hypoplastic phenotype (though mineralization defects also can occur). (2) Missense mutations affecting the N-terminal region, especially those causing changes in the putative lectin-binding domain and TRAP (tyrosine rich amelogenin protein) region of the amelogenin molecule, result in a predominantly hypomineralization/hypomaturation AI phenotype with enamel that is discolored and has retained amelogenin. (3) Mutations causing loss of the amelogenin C terminus result in a phenotype characterized by hypoplasia. The consistent association of similar hypoplastic or hypomineralization/hypomaturation AI phenotypes with specific AMELX mutations may help identify distinct functional domains of the amelogenin molecule. The phenotype-genotype correlations in this study suggest there are important functional domains of the amelogenin molecule that are critical for the development of normal enamel structure, composition, and thickness.

Amelogenesis Imperfecta↗
PubMed2005

[Difference analysis of genome-wide DNA methylation status of CpG islands between the monozygotic twins with disconcordant phenotypes of chronic hepatitis B virus infection].

OBJECTIVE: To analyse the difference of genome-wide DNA methylation status of CpG island between the monozygotic twins with disconcordant phenotype of HBV infection and to discover possible differentially methylated genes. METHODS: Modified AIMS (amplification of inter-methylated sites) method was adopted. According to the frequent sites of CpG islands (-CGCG- and -CCGG-), three groups of isochizomers with distinct methylation sensitivity (Sma I-Xma I, Hpa II-Msp I and BssH II-Pau I/BseP I) were used to modify the AIMS method. The modified AIMS method combined with Personal Molecular Imager FX system analysis and radioautographic analysis was used to make the global detection of the methylome of CpG islands. Multiple anonymous bands were compared between the twins with the Quantity One bio-soft. The different bands were cloned into T vectors and positive clones were sequenced. BLAST analysis of positive clone sequences was conducted to give the clues for the differential methylated genes between monozygotic twins with discordant phenotype of HBV infection. RESULTS: Nearly the same bands were found between one pair of twins with concordant phenotype of HBV infection. Different methylated bands were found not only between monozygotic twins with concordant phenotype but also between those with disconcordant phenotype. More differential methylated bands were found in the latter groups. By BLAST analysis with sequences of differential methylated bands, four possible genes were got. These genes might relate to the monozygotic twins with disconcordant phenotype of chronic HBV infection. CONCLUSION: Differential methylation of genes occurs in monozygotic twins with discordant phenotype of HBV infection. Whether these changes are involved in the pathogenesis of different phenotypes needs further elucidation.

Adolescent↗
PubMed1991

Concordance of P450 2D6 (debrisoquine hydroxylase) phenotype and genotype: inability of dextromethorphan metabolic ratio to discriminate reliably heterozygous and homozygous extensive metabolizers.

Debrisoquine-hydroxylase (P450 2D6) not equal to phenotype was determined in 116 individuals using dextromethorphan as the substrate probe. Polymerase chain reaction and restriction fragment length polymorphism analyses were used to detect inactivating mutations in the CYP2D6 gene and assign genotype in all 116 individuals. Using a urinary metabolic ratio (DM/DT) of > or = 0.3 to define poor metabolizer (PM) phenotypes, 96 subjects were extensive metabolizers (EM) and 20 were PMs. The CYP2D6(B) mutation was the most common mutation, present in 18% of phenotypic EM alleles and 66% of the alleles in PM phenotypes. The CYP2D6(A) mutation (8% of PM alleles) and the CYP2D6 gene deletion (2.6% of PM alleles) were found less frequently. Seven different variants of the CYP2D6 gene were found. In subjects with two mutant alleles, genotype correctly predicted the PM phenotype in 100% (n = 13). Overall, genotype agreed with phenotype assignments in 109 of 116 (94%) subjects. Seven subjects with a wild-type allele at the CYP2D6(A) and CYP2D6(B) loci were phenotypic PMs, representing the only discrepant results. These discrepancies could be due to the imprecision of phenotype assignment or to as yet unknown mutations in CYP2D6. Although the median urinary metabolic ratio was significantly lower in homozygous EMs compared with heterozygous EMs, there was extensive overlap in metabolic ratios in these two groups, indicating that the DM/DT metabolic ratio cannot reliably discriminate homozygous EMs from heterozygous EMs.

Adolescent↗
PubMed1990

Alpha-1-antitrypsin levels and prevalence of Pi variant phenotypes in adult Nigerian asthmatics.

Alpha-1-antitrypsin (A1AT) phenotypes and serum levels were determined in 99 asthmatic patients and 100 control subjects. The phenotypes encountered were PiMM 74% in asthmatics, 98% in controls; PiMZ 19% in asthmatics, 1% in controls; PiMW 3% in asthmatics, 0% in controls; and PiLM 2% in asthmatics, 1% in controls. There was one asthmatic patient with the homozygous deficient phenotype ZZ. The result revealed that there were more deficient heterozygous phenotypes in the asthmatic group than the control group. There was also a positive correlation between the number of patients with deficient phenotypes and the severity of asthma (P less than 0.02). Analysis of the serum A1AT levels revealed that as a group the asthmatic patients had significantly lower A1AT levels (1.97 +/- 0.18 g/l) than the control group (2.21 +/- 0.15 g/l) (P less than 0.01). However, there was no statistically significant difference in the A1AT serum levels of patients with P1MM phenotype and the control of the same phenotype. Statistical analysis could not be done for the other phenotypes because of the small number of subjects. Apart from the patient with PiZZ the A1AT serum levels encountered in the study were not low enough to justify replacement therapy with alpha-1-proteinase inhibitor in our asthmatic patients.

Adult↗
PubMed1985

Monoclonal antibody phenotyping of B-cell non-Hodgkin's lymphomas. The Southeastern Cancer Study Group experience.

This report describes the experience of the Southeastern Cancer Study Group (SECSG) with the frozen-section immunoperoxidase phenotyping of 162 cases of B-lineage non-Hodgkin's lymphomas. The authors used a panel of 13 different markers with varying degrees of specificity for B lymphocytes and B-cell neoplasms. All lymphomas were classified according to the International Working Formulation. Several antibodies, including anti-immunoglobulin, B1, Leu 12, and Leu 14 were B-cell-specific markers that were generally pan-reactive. Several other monoclonal antibodies, however, were selectively reactive with subpopulations of B-cell lymphomas. Three "selective-B" antigens (BA1, p24, CALLA) were found on about half of the B-cell lymphomas tested, while another three (HB31, transferrin receptor, C3d receptor) were found on about two-thirds of the lymphomas tested. Leu 1 reacted with 18% of the B-cell lymphomas, particularly the small lymphocytic lymphomas. When the reactivity of the monoclonal antibodies was compared with the histologic classification, two important points became apparent. First, with the large panel of antibodies, there was tremendous phenotypic diversity even among histologically similar tumors. Second, however, not all possible combinations of antibody phenotypes were encountered. That is, clusters of antigenic phenotypes were seen, and these phenotypes correlated to some degree with the histologic diagnosis of the tumor. Small lymphocytic and follicular lymphomas tended to be phenotypically distinct, although there was some overlap. Intermediate- and high-grade lymphomas were phenotypically more diverse. The more common phenotypes of lymphomas encountered could not be reconciled with any simple linear scheme of neoplastic B-cell differentiation.

Antibodies, Monoclonal↗
PubMed1987

Immunoglobulin phenotype in 164 B cell chronic lymphocytic leukemias: is there a relationship with initial clinical stage and survival?

In 164 B cell chronic lymphocytic leukemias, surface membrane immunoglobulin (SmIg) phenotype has been determined on lymphocytes from 158 patients (mean age = 66 years, sex ratio = 1.43) to examine the prognostic significance of cell marker phenotype. Correlation of clinical stages of the disease according to Rai and Binet and SmIg phenotype emphasized the absence of the SmIgG phenotype, suggesting more mature cells, at stage C according to Binet (11 of 13 being stage A) and at stage III or IV according to Rai. The majority of SmIg phenotypes was SmIgM +/- D. Survival curves according to SmIg heavy or light chain phenotypes did not emphasize a prognostic significance of cell marker phenotype. Peripheral lymphocytosis over 50,000/microliter correlated with a worse prognosis regardless of clinical staging and SmIg phenotype.

Aged↗
PubMed1981

Immunological definition of leukemic cell surface phenotypes.

Immunological phenotyping of blasts from over 200 children with acute lymphocytic leukemia (ALL) reveals both interpatient differences and phenotypic heterogeneity in the blast population from individual patients. A battery of five independent lymphocyte differentiation markers, erythrocyte-forming rosettes. T-cell antigens, Ia-like antigens, the common ALL antigen, and surface immunoglobulin, permit classification of all ALL specimens into four major marker groups. These are common, T-cell, B-cell, and undifferentiated ALL. Heterogeneity in the marker phenotypes within each of the major groups is observed. Within individual erythrocyte receptor-positive ALL specimens, phenotypic heterogeneity in the blast population is demonstrated. Sequential determinations of the blast phenotype during periods of active disease reveal a second example of intrapatient blast cell heterogeneity. Differences in phenotype of the dominant blast populations present prior to treatment and at relapse are observed in sequential studies of individual patients. These shifts in phenotype are nonrandom. They result most frequently from losses in single differentiation markers. A unifying hypothesis which explains these observations of phenotypic heterogeneity is that ALL blasts manifest limited lymphoid-like differentiation.

Antigens, Neoplasm↗
PubMed1993

Role of sun exposure on nevus. First study in age-sex phenotype-controlled populations.

BACKGROUND: These studies were designed to assess the influence of sun exposure on nevi in white people. To eliminate the confounding effect of age, sex, and phenotype, two parallel studies were conducted on people of the same age (17 to 24 years; median, 20 years old), sex (male), and phenotype: one in people with "red" phenotype (red or red-blond hair, white complexion on the inner part of the arm, and inability to tan) and one in people with "dark" phenotype (brown or black hair, dark complexion on the inner part of the arm, absence of freckles, and easy tanning without burning). RESULTS: In both groups, comparison of nevus counts on the inner and outer side of the upper extremities and comparison of mean density of nevi (number per square meter) in always-exposed and never-exposed skin show that the number of nevi is higher in sun-exposed areas. The density of large and atypical nevi was maximal on intermittently sun-exposed skin while the density of small nevi was maximal on always-exposed skin. The number of large nevi on intermittently exposed skin correlated with cumulative intensive exposure during beach recreation in the red phenotype group. The number of large nevi was significantly higher in red phenotypes who repeatedly experienced severe sunburns in their first 20 years of life. CONCLUSIONS: The number of nevi at the end of the second decade is influenced by cumulative sun exposure from birth. "Traumatizing" sun exposure, which is more frequent in the red phenotype than in the dark phenotype, has an influence on the number of large nevi and is therefore likely to make small nevi grow.

Adolescent↗