Biomedical subjects

A Ferreira-Gonzalez

Publications and source records attributed to A Ferreira-Gonzalez.

At least 19 recordsLinked to original sources

PubMed2006

Multilaboratory comparison of hepatitis C virus viral load assays.

We report a multilaboratory evaluation of hepatitis C virus (HCV) viral load assays to determine their linear range, reproducibility, subtype detection, and agreement. A panel of HCV RNA samples ranging in nominal concentration from 1.0 to 7.0 log10 IU/ml was constructed by diluting a clinical specimen (genotype 1b). Replicates of the panel were tested in multiple laboratories using the Abbott TaqMan analyte-specific reagent (Abbott reverse transcription-PCR [RT-PCR]), Roche TaqMan RUO (Roche RT-PCR), Roche Amplicor Monitor HCV 2.0 (Roche Monitor), and Bayer VERSANT HCV RNA 3.0 (Bayer bDNA) assays. Bayer bDNA-negative specimens were tested reflexively using the Bayer VERSANT HCV RNA qualitative assay (Bayer TMA). Abbott RT-PCR and Roche RT-PCR detected all 28 replicates with a concentration of 1.0 log10 IU/ml and were linear to 7.0 log10 IU/ml. Roche Monitor and Bayer bDNA detected 27 out of 28 and 13 out of 28 replicates, respectively, of 3.0 log10 IU/ml. Bayer TMA detected all seven replicates with 1.0 log10 IU/ml. Bayer bDNA was the most reproducible of the four assays. The mean viral load values for panel members in the linear ranges of the assays were within 0.5 log10 for the different tests. Eighty-nine clinical specimens of various genotypes (1 through 4) were tested in the Bayer bDNA, Abbott RT-PCR, and Roche RT-PCR assays. For Abbott RT-PCR, mean viral load values were 0.61 to 0.96 log10 greater than the values for Bayer bDNA assay for samples with genotype 1, 2, or 3 samples and 0.08 log10 greater for genotype 4 specimens. The Roche RT-PCR assay gave mean viral load values that were 0.28 to 0.82 log10 greater than those obtained with the Bayer bDNA assay for genotype 1, 2, and 3 samples. However, for genotype 4 samples the mean viral load value obtained with the Roche RT-PCR assay was, on average, 0.15 log10 lower than that of the Bayer bDNA. Based on these data, we conclude that the sensitivity and linear range of the Abbott and Roche RT-PCR assays enable them to be used for HCV diagnostics and therapeutic monitoring. However, the differences in the viral load values obtained with the different assays underscore the importance of using one assay when monitoring response to therapy.

Genotype↗

PubMed2004

Polymorphisms in cytokines and growth factor genes and their association with acute rejection and recurrence of hepatitis C virus disease in liver transplantation.

Acute rejection (AR) and recurrence of hepatitis C virus (HCV) infection are complications after liver transplantation (LTx). Genetic factors play a role in cytokine production as a consequence of polymorphisms within cytokine genes. Our goal was to identify genetic factors that might be associated with AR and recurrence of HCV in liver transplant recipients (LTxRs). We studied 77 Caucasian LTxRs and 100 Caucasian healthy individuals. We studied single-nucleotide polymorphisms (SNPs) in tumor necrosis factor-alpha[TNF-alpha, interleukin-6 (IL-6), IL-10, transforming growth factor-beta1, and angiotensin-converting enzyme genes by SNaPSHOT trade mark Multiplex assay. SNPs were classified as high producers (HP), intermediate producers (IP), or low producers (LP), and their association with AR and recurrence of HCV were studied. The frequency of TNF-alpha IP and HP genotypes was significantly higher in LTxRs with AR in comparison to patients without AR (TNF-alpha HP -238: 63 vs 20%, p < 0.001; TNF-alpha HP -308: 47.4 vs 20%, p = 0.02). The frequency of IL-6 IP and HP genotypes was higher in patients with AR episodes, but the difference was not statistically significant (p = 0.14). However, when we analyzed the simultaneous presence of pro-inflammatory genotypes in the same patient, we found a significant difference between patients with and without AR, respectively (42.1 vs 14.6%, p = 0.012). Moreover, the frequency of the IL-10 LP genotype was higher in LTx patients with AR (p = 0.001) compared to patients without AR. There was an association between pro-inflammatory genotypes and HCV recurrence. Our data suggest that cytokine gene polymorphisms might play a role in AR and HCV recurrence in LTxRs.

Adult↗

PubMed2001

Persistence of infectious HIV on follicular dendritic cells.

Follicular dendritic cells (FDCs) trap Ags and retain them in their native state for many months. Shortly after infection, HIV particles are trapped on FDCs and can be observed until the follicular network is destroyed. We sought to determine whether FDCs could maintain trapped virus in an infectious state for long periods of time. Because virus replication would replenish the HIV reservoir and thus falsely prolong recovery of infectious virus, we used a nonpermissive murine model to examine maintenance of HIV infectivity in vivo. We also examined human FDCs in vitro to determine whether they could maintain HIV infectivity. FDC-trapped virus remained infectious in vivo at all time points examined over a 9-mo period. Remarkably, as few as 100 FDCs were sufficient to transmit infection throughout the 9-mo period. Human FDCs maintained HIV infectivity for at least 25 days in vitro, whereas virus without FDCs lost infectivity after only a few days. These data indicate that HIV retained on FDCs can be long lived even in the absence of viral replication and suggest that FDCs stabilize and protect HIV, thus providing a long-term reservoir of infectious virus. These trapped stores of HIV may be replenished with replicating virus that persists even under highly active antiretroviral therapy and would likely be capable of causing infection on cessation of drug therapy.

Animals↗

PubMed2001

Prospective multicenter clinical evaluation of AMPLICOR and COBAS AMPLICOR hepatitis C virus tests.

We conducted a multicenter clinical evaluation of the second versions of the manual AMPLICOR and the semiautomated COBAS AMPLICOR tests for hepatitis C virus (HCV) RNA (Roche Molecular Systems, Inc., Pleasanton, Calif.). The performance characteristics of these HCV RNA tests for diagnosis of active viral infection were determined by comparison to anti-HCV serological test results, alanine aminotransferase levels, and liver biopsy histology results. A total of 878 patients with clinical or biochemical evidence of liver disease were enrolled at four hepatology clinics. A total of 1,089 specimens (901 serum and 188 plasma) were tested with the AMPLICOR test. Sensitivity compared to serology was 93.1% for serum and 90.6% for plasma. The specificity was 97% for serum and 93.1% for plasma. A total of 1,084 specimens (896 serum and 188 plasma) were tested with the COBAS test. Sensitivities for serum and plasma were the same as with the AMPLICOR test. The specificity was 97.8% for serum and 96.6% for plasma. Of the 69 specimens with false-positive and false-negative AMPLICOR test results relative to those of serology, alternative primer set (APS) reverse transcription (RT)-PCR analysis showed that the AMPLICOR test provided the correct result relative to the specimens containing HCV RNA in 64 (92.7%) specimens. Similarly, 66 of 67 (98.5%) false-positive and false-negative COBAS test results were determined to be correct by APS RT-PCR analysis. There were no substantive differences in clinical performances between study sites, patient groups, specimen types, storage conditions (-20 to -80 degrees C versus 2 to 8 degrees C), or anticoagulants (EDTA versus acid citrate dextrose) for either test. Both tests showed >99% reproducibility within runs, within sites, and overall. We conclude that these tests can reliably detect the presence of HCV RNA, as evidence of active infection, in patients with clinical or biochemical evidence of liver disease.

Adolescent↗

PubMed2000

Fluorescence in situ hybridization detectable mosaicism for Angelman syndrome with biparental methylation.

We present a child with mild to moderate global developmental delay including severe speech impairment, inappropriate happy demeanor, wide-based gait, frequent ear infections with mild hearing loss, deep-set eyes, a wide mouth, widely-spaced teeth, normal head circumference, and no seizures. Results of peripheral blood lymphocyte chromosomal analysis with GTG banding were normal. However, fluorescence in situ hybridization (FISH) studies showed mosaicism for a deletion of probes (D15S10 and SNRPN) from the Angelman syndrome (AS) critical region with approximately 40% of peripheral lymphocytes having the deletion. The deleted chromosome 15 also showed centromeric duplication, which was detected with a D15Z1 probe [46,XX, dic(15)(pter-->q11.1::p11.2-->q11. 1::q13-->qter)]. The same duplication pattern was observed in 30% of the nuclei obtained from a buccal smear. Methylation studies using polymerase chain reaction with sodium bisulfite-treated DNA demonstrated a normal biparental methylation pattern. To the best of our knowledge, this is the first case with AS and a FISH detectable deletion in a mosaic pattern. We recommend FISH studies for the detection of mosaicism in the patients with AS clinical findings even if results of the methylation studies are normal.

Angelman Syndrome↗

PubMed2000

Genetic changes in solid tumors.

Although most solid tumors are treated surgically, determining the genetic changes present in the tumor of an individual patient is becoming increasingly important for managing the oncology patient. Our knowledge of the genetic alterations that characterize and predispose to solid tumors continues to expand. Concurrently, the advent of newer technologies such as DNA chips has the potential to enable a more rapid and comprehensive assessment of these changes. The ultimate goal of this new information and technology is to provide sensitive and specific tests that reduce unnecessary procedures and optimize therapy. This review addresses the utility of molecular testing in evaluating cancer. A review of the current technology and hereditary cancer syndromes is also presented.

Breast Neoplasms↗

PubMed2000

Detection of a novel truncated WT1 transcript in human neoplasia.

BACKGROUND: The Wilms' tumor 1 (WT1) gene encodes a transcription factor critical in urogenital development. Using a new model of prostate cancer progression that permits comparison of the cellular and molecular properties of increasingly aggressive sublines of simian virus 40 large T-antigen-immortalized human prostate epithelial cells within the same lineage, the role of WT1 in tumorigenesis was investigated. METHODS AND RESULTS: Using RT-PCR and northern blotting, we identified a novel truncated WT1 transcript in these prostate cancer cell lines. This 2.1-kb transcript consisted of the coding region of the zinc-finger domain of WT1, together with a portion of intron 5 at the 5' end of the transcript. Furthermore, two peptides were detected by western blotting using antibodies to epitopes of the COOH terminus of WT1. Using RT-PCR, the 2.1-kb transcript was also detected in leukemia cell line K562, breast cancer cell line MCF7, and blood samples from patients with acute leukemia. CONCLUSION: These novel findings in both cell lines and patient-derived specimens suggest this new WT1 gene alteration has a potential role in the development of new diagnostic assays for some human malignancies.

Blotting, Northern↗

PubMed2000

Validation of a multiplex methylation-sensitive PCR assay for the diagnosis of Prader-Willi and Angelman's syndromes.

BACKGROUND: Prader-Willi (PWS) and Angelman's (AS) syndromes are two distinct clinical entities caused by alterations in an identical but differentially methylated region of DNA on chromosome 15q. Highly complex laboratory tests are required for diagnosis because the disorders are caused by several genetic mechanisms. Methylation-specific PCR (MSPCR) is a relatively simple alternative method to detect the methylation status of the PWS/AS region. METHODS AND RESULTS: DNA was treated with sodium bisulfite, with alterations to the published method in which a neutralization step after the alkali treatment of the modified DNA enabled the use of the modified product directly in the PCR, eliminating the need for ethanol precipitation. Multiplex MSPCR using primers to methylated and unmethylated DNA was optimized to yield equal amplification efficiency for both products. Complete concordance was observed during the clinical validation of 40 previously characterized samples, except for one patient with mosaic AS detected by fluorescence in situ hybridization. CONCLUSION: We have developed and validated a multiplex MSPCR assay with alterations of the original published protocol that is technically robust and reproducible and can be used as a screening assay to detect PWS and AS.

Angelman Syndrome↗

PubMed2000

Can polymerase chain reaction help distinguish benign from malignant lymphoid aggregates in bone marrow aspirates?

OBJECTIVE: Although morphologic and immunologic clues are helpful in distinguishing benign from malignant lymphoid aggregates in bone marrow biopsies, there remain some cases in which it is not possible to arrive at a definitive diagnosis. Since the malignant aggregates are monoclonal B-cell proliferations, we sought to determine whether performing polymerase chain reaction for the immunoglobulin heavy-chain locus would be helpful in distinguishing these 2 entities. METHODS AND RESULTS: Scrapings from unstained bone marrow aspirate smears or touch preparations of bone marrow biopsies from 15 patients with benign bone marrow lymphoid aggregates and 18 patients with malignant lymphoid infiltrates were analyzed for rearrangements of the FR3 region of the immunoglobulin heavy-chain gene locus by a heminested polymerase chain reaction procedure. All specimens had amplifiable DNA, as shown by amplification of the ras proto-oncogene. None of the 15 cases of benign bone marrow lymphoid aggregates demonstrated clonality upon amplification of the immunoglobulin heavy-chain gene locus. In contrast, 8 of the 18 malignant samples were positive (P =.01 by chi(2) test; sensitivity, 44%; specificity, 100%; positive predictive value, 100%; negative predictive value, 60%). There was a tendency for there to be more lymphocytes in stained bone marrow aspirate smears from the cases of malignant lymphoid aggregates with a positive polymerase chain reaction result than in those without demonstrable clonality (36.0 +/- 35.4% vs 9.8 +/- 8.0%, P =.13). CONCLUSIONS: Polymerase chain reaction for the immunoglobulin heavy-chain gene locus may help distinguish benign from malignant bone marrow lymphoid aggregates. Although the presence of false-negative samples may be related to the relative lack of lymphocytes in the bone marrow aspirates, other factors, such as the lack of amplification of the FR3 region of the immunoglobulin heavy-chain gene locus in particular tumors, cannot be ruled out with certainty.

Biopsy↗

PubMed2000

Primary T-cell-rich B-cell lymphoma masquerading as a meningioma.

Primary dural lymphoma is rare, and few of the small number of cases reported to date have been classified using immunohistochemical techniques. To our knowledge, we report the first case of T-cell-rich B-cell lymphoma (diffuse mixed small cell and large cell) presenting as a solitary intracranial dural mass. Cytologic and frozen sections prepared during intraoperative consultation revealed a polymorphic population of lymphocytes suspicious for an inflammatory process. Permanent sections of the dura showed a diffusely infiltrating mass composed of mature lymphocytes peppered with large atypical lymphocytes. Immunohistochemical stains identified the small lymphocytes as T cells (CD3 and CD43) and the large atypical lymphocytes as B cells (CD20). Evidence of rearranged immunoglobulin heavy-chain genes demonstrated B-cell monoclonality. Differentiating between inflammatory and neoplastic lymphocytic masses of the dura obviously has important therapeutic and prognostic significance and may require immunohistochemical and molecular techniques.

Antigens, CD↗

PubMed2000

Enhanced analytical sensitivity of a quantitative PCR for CMV using a modified nucleic-acid extraction procedure.

Accurate and rapid diagnosis of CMV disease in immunocompromised individuals remains a challenge. Quantitative polymerase chain reaction (QPCR) methods for detection of CMV in peripheral blood mononuclear cells (PBMC) have improved the positive and negative predictive value of PCR for diagnosis of CMV disease. However, detection of CMV in plasma has demonstrated a lower negative predictive value for plasma as compared with PBMC. To enhance the sensitivity of the QPCR assay for plasma specimens, plasma samples were centrifuged before nucleic-acid extraction and the extracted DNA resolubilized in reduced volume. Optimization of the nucleic-acid extraction focused on decreasing or eliminating the presence of inhibitors in the pelleted plasma. Quantitation was achieved by co-amplifying an internal quantitative standard (IS) with the same primer sequences as CMV. PCR products were detected by hybridization in a 96-well microtiter plate coated with a CMV or IS specific probe. The precision of the QPCR assay for samples prepared from untreated and from pelleted plasma was then assessed. The coefficient of variation for both types of samples was almost identical and the magnitude of the coefficient of variations was reduced by a factor of ten if the data were log transformed. Linearity of the QPCR assay extended over a 3.3-log range for both types of samples but the range of linearity for pelleted plasma was 20 to 40,000 viral copies/ml (vc/ml) in contrast to 300 to 400,000 vc/ml for plasma. Thus, centrifugation of plasma before nucleic-acid extraction and resuspension of extracted CMV DNA in reduced volume enhanced the analytical sensitivity approximately tenfold over the dynamic range of the assay.

Centrifugation↗

PubMed1999

Clinical utility of a quantitative polymerase chain reaction for diagnosis of cytomegalovirus disease in solid organ transplant patients.

BACKGROUND: Accurate and rapid diagnosis of human cytomegalovirus (HCMV) disease in solid organ transplant patients remains a challenge. We evaluated the clinical utility of a quantitative polymerase chain reaction (QPCR) method to diagnose transplant patients with HCMV disease. METHODS: A total of 429 plasma samples from 121 solid organ transplant patients were prospectively collected and evaluated for HCMV using a QPCR assay. To enhance the sensitivity of the QPCR assay, plasma samples were centrifuged in a manner designed to concentrate the virions before nucleic acid extraction. Quantitation was achieved by co-amplifying an internal quantitative standard (IS) that contained the same primer sequences as for HCMV. Polymerase chain reaction products were detected by hybridization to 96-well microtiter plates coated with either a HCMV- or an IS-specific probe. RESULTS: A total of 103 patients had all samples negative by QPCR. None of the 103 patients developed HCMV disease during the study. In contrast, 18 patients showed at least 1 sample positive by the QPCR assay, but only 8 of these developed HCMV disease. The mean viral load value for patients without HCMV disease was 93 viral copies (vc) per ml of plasma (range: 35-325 vc/ml plasma) and for the 8 patients with HCMV disease was 67,686 vc/ml plasma (range: 167-1,325,000 vc/ml plasma) (P<0.001). Using a cut-off value of 100 vc/ml plasma and clinical diagnosis of HCMV disease, the QPCR assay showed a sensitivity of 100% and specificity of 99.1%. CONCLUSION: HCMV viral load may be useful in the diagnosis of HCMV disease in solid organ transplant patients.

Adolescent↗

PubMed1999

Utility of cytomegalovirus viral load in renal transplant patients in Argentina.

BACKGROUND: Cytomegalovirus (CMV) is the most prevalent viral disease in solid organ transplantation. Detection of CMV DNA in peripheral blood mononuclear cells (PBMC) by polymerase chain reaction (PCR) frequently occurs in renal allograft recipients, yielding false positive results in seropositive patients free of CMV disease. We evaluated the clinical utility of a quantitative PCR-enzyme-linked immunosorbent assay (ELISA) for identifying patients with CMV disease. METHODS: Three hundred and fifty samples from 65 consecutive renal transplant recipients were studied. DNA was extracted from PBMC weekly up to the day of discharge and after any further admission. Samples were tested by a qualitative PCR method, and all positive samples were further studied by a quantitative PCR-ELISA method. The quantitative PCR-ELISA method used an internal standard (IS) that contained the primer sequences used in the qualitative CMV PCR. Detection and quantification was performed in 96-well plates coated with IS or CMV specific probes. RESULTS: Forty-one of 65 patients (63.1%) showed positive results by the qualitative PCR, but only 8 of these patients were diagnosed with CMV disease. Positive samples were re-analyzed by the quantitative assay. The 8 patients with CMV disease had a mean CMV viral load of 1,438+/-687 viral copies (VC)/10(6) PBMC, and the 33 without CMV disease had a mean value of 219.6+/-117.2 VC/10(6) PBMC (P<0.01). None of the 33 patients without CMV disease had viral loads higher than 500 VC/10(6) PBMC. Using 500 VC/10(6) PBMC as a cut-off value for CMV disease, the quantitative PCR showed a sensitivity and specificity of 100% compare to clinical diagnosis. CONCLUSION: CMV viral load may be useful in the diagnosis of CMV disease in renal transplant patients.

Adolescent↗

PubMed1999

Overexpression of C-NEU and C-MET during rat liver cholangiocarcinogenesis: A link between biliary intestinal metaplasia and mucin-producing cholangiocarcinoma.

Based on limited but compelling immunohistochemical data demonstrating individual overexpression of the tyrosine kinase growth factor receptors, c-erbB-2 and c-met, in significant percentages of human cholangiocarcinoma (ChC), we investigated if combined overexpression of both c-neu, the rat homologue of c-erbB-2, and c-met, the receptor for hepatocyte growth factor/scatter factor (HGF/SF), might represent a characteristic, early event associated with furan-induced cholangiocarcinogenesis in rat liver. Specifically, through the use of immunohistochemistry, in situ hybridization (ISH), and Western and Northern blotting, we found that both c-neu and c-met are prominently overexpressed in intestinal metaplastic lesions in early putative precancerous cholangiofibrotic tissue formed in the livers of rats after 6 weeks of furan treatment when compared with normal and hyperplastic intrahepatic biliary epithelia. We further demonstrated that c-neu and c-met are concordantly overexpressed in neoplastic glandular epithelia in later-developed primary "intestinal-type" of ChC formed in the livers of furan-treated rats, as well as in subsequently derived transplantable mucin-producing tumors. Overexpression of c-neu and c-met correlated with increased proliferating cell nuclear antigen (PCNA)-labeling indices, which were determined to be three to four times higher in intestinal metaplastic glands in precancerous cholangiofibrotic tissue and in neoplastic glands in the primary "intestinal type" of ChC than in hyperplastic bile ductular structures within either cholangiofibrotic or bile duct-ligated (BDL) livers. The c-neu and c-met receptor proteins overexpressed in different in vivo passages of a transplantable ChC each contained immunoreactive phosphotyrosines, indicating an activated state. However, we did not detect evidence of either gene amplification of c-neu or c-met or of a common transmembrane-activating mutation in c-neu expressed in transplantable ChC. Our findings indicate that altered expression of c-neu and c-met occurs relatively early in the process of furan-induced cholangiocarcinogenesis in rat liver and may play a potentially important role in its pathogenesis. They further indicate a common alteration in tyrosine kinase growth factor receptor expression linking early putative precancerous intestinal metaplastic lesions in liver to later-developed mucin-producing biliary cancer.

Animals↗

PubMed1999

A randomized, controlled trial of maintenance interferon therapy for patients with chronic hepatitis C virus and persistent viremia.

BACKGROUND & AIMS: : At least half of patients with chronic hepatitis C virus (HCV) fail to respond to interferon or interferon/ribavirin therapy. Histological improvement is observed in some nonresponders. We conducted a randomized, controlled trial to determine if maintenance interferon therapy could prevent histological progression in this subset of nonresponders. METHODS: Fifty-three patients with chronic HCV were enrolled. All were HCV-RNA positive after 6 months of treatment with interferon alfa-2b but had a histological response. Twenty-seven of the patients were randomly assigned to continue interferon (3 MU 3 times weekly) for 24 months; 26 patients discontinued treatment and were observed prospectively. Alanine aminotransferase (ALT) level and HCV-RNA titer were monitored, and liver biopsy was repeated every 12 months. RESULTS: Before interferon therapy, the 2 groups were well matched for all demographic factors, serum ALT (94.0 +/- 15.6), log HCV-RNA titer (5. 85 +/- 0.15 copies/mL), histology score (9.5 +/- 0.2), and percentage with cirrhosis (25%). After 6 months of treatment, significant reductions (P < 0.05) in serum ALT level (62.6 +/- 9.6), log HCV-RNA titer (4.79 +/- 0.13 copies/mL), and hepatic inflammation (4.0 +/- 0.2) were observed. These improvements were maintained in the patients randomized to continue interferon. Stopping treatment was associated with an increase in serum ALT, log HCV-RNA, and hepatic inflammation back to baseline. After 30 months of treatment, mean fibrosis score declined from 2.5 to 1.7 and 80% of patients had histological improvement (P < 0.03). Discontinuation of interferon was associated with an increase in mean fibrosis score from 2.2 to 2.4 and worsening of hepatic histology in 30% of patients (P < 0.01). CONCLUSIONS: These data support the hypothesis that maintenance interferon may prevent histological progression of chronic HCV in patients who remain viremic.

Alanine Transaminase↗

PubMed1997

Detection of a common mutation in factor V gene responsible for resistance to activate protein C causing predisposition to thrombosis.

Hereditary predisposition to thrombosis due to activated protein C resistance (APCR) has been attributed to a missense mutation in the factor V gene at nucleotide 1691 (G to A), causing replacement of arginine at codon 506 with glutamine. Using an RFLP-PCR assay to detect this mutation, we measured a prevalence of 3.3% in healthy Caucasians and 1.25% in healthy African-Americans. In addition, we evaluated a total of 90 consecutive specimens submitted to the coagulation laboratory at the Medical College of Virginia for the presence of this mutation. We compared our results for 78 of these specimens with the values measured by a modified partial thromboplastin assay, the COATEST. Twelve of the 90 samples could not be tested using the COATEST because the patients were undergoing anticoagulant therapy. One of the latter 12 specimens was positive by the RFLP-PCR test. Using the genetic test as the definitive assay and the cutoff value established for distinguishing between normal and abnormal results by the COATEST, the COATEST had a sensitivity of 50% and specificity of 93% for the detection of factor V mutation. Analysis of the 90 samples stratified by ethnic groups revealed a frequency of mutation of 13.3% for Caucasians and 6.88% for African-Americans, although with the present sample size, the difference was not statistically significant. Although the COATEST is technically simpler to perform than the genetic test for diagnosing the presence of the factor V mutation, its use for this purpose is limited due to low sensitivity. Thus where this disorder is clinically suspected, submission of the specimen directly for genetic testing by RFLP-PCR or equivalent assay should be considered.

Black People↗

PubMed1997

Relationship between biochemical, virological, and histological response during interferon treatment of chronic hepatitis C.

The present study was conducted to evaluate the relationship between biochemical, virological, and histological response during the course of interferon therapy. Ninety consecutive patients with well-documented chronic hepatitis C virus (HCV) were treated with 5 MU of interferon alfa-2b three times weekly for 6 months. Liver biopsy was performed, and serum HCV RNA titer was measured before and at the completion of interferon treatment. Normalization of serum alanine transaminase (ALT) concentration (biochemical response) was observed in 50% of patients. In these patients, Knodell score declined significantly from 9.6 +/- 0.5 to 5.0 +/- 0.5 (P < .01), and 75% became HCV RNA negative. The remaining patients (50%) were biochemical nonresponders; mean Knodell score declined from 9.6 +/- 0.5 to 7.7 +/- 0.5 (P < .01), and 11% became HCV RNA negative. For both biochemical responders and nonresponders, the decline in Knodell score was confined to the components of hepatic inflammation (piecemeal necrosis + lobular + portal inflammation); no change in fibrosis was observed. Hepatic inflammation declined by 5 points or more in 69% of biochemical responders and 48% of biochemical nonresponders, and by at least 50% from pretreatment values in 74% and 38% of biochemical responders and biochemical nonresponders, respectively. For all patients (both biochemical responders and nonresponders) who remained viremic at the conclusion of interferon therapy, the reduction in hepatic inflammation was a linear function of the decline in HCV RNA titer. We conclude that more than one third of patients who had no biochemical response after 6 months of interferon therapy achieved a similar improvement in hepatic histology as was observed in patients with biochemical response. This improvement in hepatic histology appeared to correlate with a reduction in HCV RNA titer, especially in patients who remained viremic.

Adult↗

PubMed1996

Pitfalls in establishing a molecular diagnostic laboratory.

Diseases are increasingly being defined in terms of genetic alterations. A body of information termed "molecular pathogenesis" is evolving which provides a framework for integrating the rapidly accumulating genetic information with the related disease process. Molecular methods with their increased sensitivity and specificity are required to gather this information. A major challenge now lies in the transfer of this molecular technology from a research environment to the clinical testing arena. Technical issues, patented technology, special facilities, personnel, and regulatories issues imposed by CLIA'88, require those desiring to perform molecular tests to pay special attention to laboratory design, personnel training, and test menu development. Although establishing a successful molecular diagnostics laboratory is a complex and difficult task, the added value of these tests can have a tremendous impact in disease diagnosis and patient management.

Facility Design and Construction↗