William E. Schreiber

Educating medical students in laboratory medicine: a proposed curriculum.

As the 100th anniversary of the Flexner report nears, medical student education is being reviewed at many levels. One area of concern, expressed in recent reports from some national health care organizations, is the adequacy of training in the discipline of laboratory medicine (also termed clinical pathology). The Academy of Clinical Laboratory Physicians and Scientists appointed an ad hoc committee to review this topic and to develop a suggested curriculum, which was subsequently forwarded to the entire membership for review. The proposed medical student laboratory medicine curriculum defines goals and objectives for training, provides guidelines for instructional methods, and gives examples of how outcomes can be assessed. This curriculum is presented as a potentially helpful outline for use by medical school faculty and curriculum committees.

Heteroduplex analysis detects frameshift and point mutations in patients with acute intermittent porphyria

We used heteroduplex analysis to screen for mutations in the porphobilinogen deaminase gene in 21 patients with acute intermittent porphyria (AIP). Unique banding patterns were investigated by direct sequencing of polymerase chain reaction products and, when indicated, sequencing of cloned DNA containing the exon of interest. Two frameshift mutations were found, a 2-bp deletion in exon 5 and a 1-bp insertion in exon 7. Both mutations generate a premature stop codon. Two point mutations, in exons 10 and 14, were also observed. The C→T mutation in exon 10 codes for an Arg173 to Trp substitution, while a G→A mutation in exon 14 changes Trp283 into a premature stop codon. This study extends the spectrum of mutations that cause AIP and demonstrates the utility of heteroduplex analysis as a screening technique.

Incomplete testosterone suppression with luteinizing hormone-releasing hormone agonists: does it happen and does it matter?

Study Type – Therapy (case series)

MUC1 gene-derived glycoprotein assays for monitoring breast cancer (CA 15-3, CA 27.29, BR): are they measuring the same antigen?

CONTEXT There are 2 general types of assays measuring MUC1 gene-derived glycoprotein: assays for cancer antigen (CA) 15-3, which are sandwich assays, and assays for CA 27.29, which are competitive assays. These 2 types of assays measure slightly different parts of this tandem-repeat molecule. Across-method assay differences hinder the exchange of patient test values among integrated health care networks and among countries. OBJECTIVE This report evaluates the method differences among these assays to determine if the differences between these assays are mainly related to variations in calibration or differences in analyte specificity. DESIGN Data from 22 College of American Pathologists survey challenges were analyzed to compare 10 commercial assay methods for these 2 related analytes. In addition, data from 58 patient samples were analyzed to compare 3 of these assays. RESULTS The linear correlation coefficients comparing the within-method medians of these proficiency test distributions were very high (>0.99) for all of the methods; however, the regression slopes varied from 0.836 to 1.095. The regression slopes for the patient specimens varied similarly, but the correlation coefficients were lower. CONCLUSIONS This study indicates that many of the test value differences for these measurements are due to differences in assay calibration rather than differences in the specificity of the assay measurement systems. Survey test data potentially could be used to help harmonize these assay differences.

Oligoclonal bands and cerebrospinal fluid markers in multiple sclerosis: associations with disease course and progression

Background: The use of oligoclonal bands (OCBs) and cerebrospinal fluid (CSF) parameters are established in the diagnosis of MS, but poorly as markers of disease. Objective: To investigate the role of OCBs in disease course and progression. Methods: CSF data for 1120 patients with MS were analyzed for associations between OCBs and CSF parameters and clinical data (disease course [relapsing-onset MS (ROMS) vs primary-progressive MS (PPMS)]), disability progression (proportion reaching Expanded Disability Status Scale 6 within 10 years of onset and progression index) and ethnicity. Results: Of patients with MS, 72.5% had detectable OCBs. For patients with detectable OCBs, 84.6% had ROMS and 15.4% PPMS versus 89.7% and 10.3%, respectively for those without detectable OCBs (p=0.04). Total CSF IgG and protein levels were higher in PPMS compared with ROMS (p<0.001). Disease progression appeared independent of OCB status. Patients with CSF (vs without) data were more likely to be male, older at onset, have PPMS and lack optic neuropathy at onset (p<0.001). Conclusions: OCB positivity and elevated total CSF IgG and protein were moderately associated with a PPMS disease course, but not disease progression. Patients with atypical clinical presentations were more likely to have had CSF work-up, suggesting a testing bias.

Hereditary coproporphyria: Exon screening by heteroduplex analysis detects three novel mutations in the coproporphyrinogen oxidase gene

Hereditary coproporphyria is a dominantly inherited disorder of porphyrin metabolism caused by a partial deficiency of coproporphyrinogen oxidase, the sixth enzyme in the heme synthetic pathway. We investigated the molecular basis of hereditary coproporphyria in three unrelated patients, amplifying each exon of the coproporphyrinogen oxidase gene and performing heteroduplex analysis to look for mutations. Unique heteroduplex patterns were noted in exons 2, 3, and 6. Sequencing revealed different mutations in each patient: a G→A point mutation encoding a glutamic acid to lysine substitution at codon 101 (E101K), a C→T point mutation encoding a proline to serine substitution at codon 149 (P149S), and a one base‐pair insertion in exon 6 (968insT). No other mutations were found on sequencing the remaining exons and their intron‐exon junctions. The two point mutations affect amino acids that are conserved in all species studied to date. The one base‐pair insertion in exon 6 is the first frameshift mutation to be described in the coproporphyrinogen oxidase gene. This study adds three new mutations to those that have been previously reported, and all have been restricted to single families. These results indicate that hereditary coproporphyria is a genetically heterogeneous disease. Hum Mutat 10:196–200, 1997.

Comparison of fresh frozen serum to proficiency testing material in College of American Pathologists surveys: α-fetoprotein, carcinoembryonic antigen, human chorionic gonadotropin, and prostate-specific antigen

CONTEXT Most proficiency testing materials (PTM) contain an artificial matrix that may cause immunoassays to perform differently with this material than with clinical samples. We hypothesized that matrix effects would be reduced by using fresh frozen serum (FFS). OBJECTIVE To compare the performance of an FFS pool to standard PTM for measurement of alpha-fetoprotein, carcinoembryonic antigen, human chorionic gonadotropin (hCG), and prostate-specific antigen (PSA). DESIGN One FFS specimen and 4 different admixtures of PTM were distributed in the 2003 College of American Pathologists K/KN-A (for alpha-fetoprotein, carcinoembryonic antigen, hCG, and total and free PSA) and C-C (hCG only) Surveys. PARTICIPANTS The number of laboratories that participated in the surveys varied from a low of 288 (free PSA, K/KN-A Survey) to a high of 2659 (hCG, C-C Survey). MAIN OUTCOME MEASURES Method imprecision and method bias were compared between the FFS specimen and the standard PTM specimen with the closest value. Method imprecision was determined by calculating the coefficients of variation for each method and for all methods combined. Bias was defined as the proportional difference between peer-group mean and the median of all method means. RESULTS The FFS specimen gave significantly higher imprecision than PTM for the analytes alpha-fetoprotein, carcinoembryonic antigen, total PSA, and free PSA. For hCG, no substantial imprecision differences were observed in both surveys. Bias was significantly greater for the alpha-fetoprotein, carcinoembryonic antigen, and total PSA assays and significantly lower for the hCG and free PSA assays when comparing the FFS with the PTM. CONCLUSIONS Fresh frozen serum did not provide consistently lower imprecision or bias than standard PTM in a survey of commonly ordered tumor markers.

Porphyria presenting with bilateral radial motor neuropathy: Evidence of a novel gene mutation

The authors identified a novel mutation of the porphobilinogen deaminase (PBG-D) gene in a patient with acute intermittent porphyria presenting with severe and bilateral axonal radial motor neuropathy. Electrophysiologic studies revealed prominent involvement of distal radial nerves in the setting of mild polyneuropathy. Analysis of the PBG-D gene revealed a single base-pair insertion (887insA) in exon 14.

Pathology in the Era of Web 2.0

In the past few years, the term Web 2.0 has become a descriptor for the increased functionality of Web sites, including those with medical content. Most physicians do not know what Web 2.0 means or how it can impact their work lives. This review provides some background on the evolution of Web 2.0 and describes how its features are being incorporated into medical Web sites. Some potential applications of Web 2.0 in pathology and laboratory medicine are discussed, as are the issues that must be considered when adopting this new technology.

Safety of Lidocaine 15% and Prilocaine 5% Topical Ointment Used as Local Anesthesia for Intense Pulsed Light Treatment

BACKGROUND Literature cautions against applying lidocaine 15%/prilocaine 5% over an area larger than 300 cm2. The area of the face, neck, and chest is 400 cm2 or greater. OBJECTIVE To investigate the safety of lidocaine 15%/prilocaine 5% topical anesthetic ointment used as anesthesia for intense pulsed light (IPL) treatment. METHODS AND MATERIALS Lidocaine 15%/prilocaine 5% ointment was applied to the face only (n=10) for 30 ± 15 minutes or to the face, neck, and chest (n=10) for a total of 60 ± 15 minutes before IPL. Blood lidocaine and prilocaine levels were measured. Adverse events were recorded. RESULTS For the entire cohort, blood was drawn 25.6 ± 6.6 minutes after IPL was completed. In the face only group, the mean lidocaine level was 0.122 ± 0.125 μg/mL, and the mean prilocaine level was 0.048 ± 0.029 μg/mL. In the face, neck, and chest group, the mean lidocaine level was 0.272 ± 0.208 μg/mL, and the mean prilocaine level was 0.087 ± 0.060 μg/mL. No adverse events related to systemic toxicity were observed or reported to the nurse. At the 24‐hour follow‐up, no subject reported symptoms of systemic toxicity after leaving the clinic. CONCLUSION Under the conditions of this study, topical lidocaine 15%/prilocaine 5% produces low levels of systemic absorption. The authors have indicated no significant interest with commercial supporters.