Validation of Thermal Imaging and the ALT-70 Prediction Model to Differentiate Cellulitis From Pseudocellulitis

Importance

Cellulitis is misdiagnosed in up to 30% of cases due to mimic conditions termed pseudocellulitis. The resulting overuse of antibiotics is a threat to patient safety and public health. Surface thermal imaging and the ALT-70 (asymmetry, leukocytosis, tachycardia, and age ≥70 years) prediction model have been proposed as tools to help differentiate cellulitis from pseudocellulitis.

Objectives

To validate differences in skin surface temperatures between patients with cellulitis and patients with pseudocellulitis, assess the optimal temperature measure and cut point for differentiating cellulitis from pseudocellulitis, and compare the performance of skin surface temperature and the ALT-70 prediction model in differentiating cellulitis from pseudocellulitis.

Design, Setting, and Participants

This prospective diagnostic validation study was conducted among patients who presented to the emergency department with acute dermatologic lower extremity symptoms from October 11, 2018, through March 11, 2020. Statistical analysis was performed from July 2020 to March 2021 with additional work conducted in September 2023.

Main Outcomes and Measures

Temperature measures for affected and unaffected skin were obtained. Cellulitis vs pseudocellulitis was assessed by a 6-physician, independent consensus review. Differences in temperature measures were compared using the t test. Logistic regression was used to identify the temperature measure and associated cut point with the optimal performance for discriminating between cellulitis and pseudocellulitis. Diagnostic performance characteristics for the ALT-70 prediction model, surface skin temperature, and both combined were also assessed.

Results

The final sample included 204 participants (mean [SD] age, 56.6 [16.5] years; 121 men [59.3%]), 92 (45.1%) of whom had a consensus diagnosis of cellulitis. There were statistically significant differences in all skin surface temperature measures (mean temperature, maximum temperature, and gradients) between cellulitis and pseudocellulitis. The maximum temperature of the affected limb for patients with cellulitis was 33.2 °C compared with 31.2 °C for those with pseudocellulitis (difference, 2.0 °C [95% CI, 1.3-2.7 °C]; P < .001). The maximum temperature was the optimal temperature measure with a cut point of 31.2 °C in the affected skin, yielding a mean (SD) negative predictive value of 93.5% (4.7%) and a sensitivity of 96.8% (2.3%). The sensitivity of all 3 measures remained above 90%, while specificity varied considerably (ALT-70, 22.0% [95% CI, 15.8%-28.1%]; maximum temperature of the affected limb, 38.4% [95% CI, 31.7%-45.1%]; combination measure, 53.9% [95% CI, 46.5%-61.2%]).

Conclusions and Relevance

In this large diagnostic validation study, significant differences in skin surface temperature measures were observed between cases of cellulitis and cases of pseudocellulitis. Thermal imaging and the ALT-70 both demonstrated high sensitivity, but specificity was improved by combining the 2 measures. These findings support the potential of thermal imaging, alone or in combination with the ALT-70 prediction model, as a diagnostic adjunct that may reduce overdiagnosis of cellulitis.

In-Home COVID-19 Testing for Children With Medical Complexity: Feasibility and Association With School Attendance and Safety Perceptions

The REstarting Safe Education and Testing program for children with medical complexity was implemented in May 2021 at the University of Wisconsin to evaluate the feasibility of in-home rapid antigen COVID-19 testing among neurocognitively affected children. Parents or guardians administered BinaxNOW rapid antigen self-tests twice weekly for three months and changed to symptom and exposure testing or continued surveillance. In-home testing was feasible: nearly all (92.5%) expected tests were conducted. Symptomatic testing identified seven of nine COVID-19 cases. School safety perceptions were higher among those opting for symptom testing. Clinical Trials.gov identifier: NCT04895085. (Am J Public Health. 2022;112(S9):S878-S882. https://doi.org/10.2105/AJPH.2022.306971).

COVID-19 Vaccination Coverage Among People Experiencing Homelessness in a Highly Vaccinated Midwest County-Dane County, Wisconsin, 2021

People experiencing homelessness (PEH) are at increased risk for coronavirus disease 2019 (COVID-19) infection. This study assessed COVID-19 vaccination coverage among vaccine-eligible PEH (5 years and older) stratified by demographic characteristics. PEH were less likely to complete a primary vaccination series than the Dane County population (32.0%; 95% confidence interval [CI], 30.3%–33.8% vs 82.4%; 95% CI, 82.3%–82.5%) and were less likely to have received a booster when eligible (30.8%; 95% CI, 27.8%–33.9% vs 67.2%; 95% CI, 67.1%–67.4%). Vaccination rates were lowest among young PEH and PEH of color.

COVID-19 Vaccination Intentions for Children With Medical Complexity

OBJECTIVES

The chronic conditions and functional limitations experienced by children with medical complexity (CMC) place them at disproportionate risk for COVID-19 transmission and poor outcomes. To promote robust vaccination uptake, specific constructs associated with vaccine hesitancy must be understood. Our objective was to describe demographic, clinical, and vaccine perception variables associated with CMC parents' intention to vaccinate their child against COVID-19.

METHODS

We conducted a cross-sectional survey (June-August 2021) for primary caregivers of CMC between ages 5 to 17 at an academic medical center in the Midwest. Multivariable logistic regression examined associations between vaccination intent and selected covariates.

RESULTS

Among 1330 families, 65.8% indicated vaccination intent. In multivariable models, demographics had minimal associations with vaccination intent; however, parents of younger children (<12 years) had significantly lower adjusted odds of vaccination intent (adjusted odds ratio [95% confidence interval]: 0.26 [0.17-0.3]) compared to parents of older children (≥12 years). CMC with higher severity of illness, ie, those with ≥1 hospitalization in the previous year (versus none) or >1 complex chronic condition (vs 1), had higher adjusted odds of vaccination intent (1.82 [1.14-2.92] and 1.77 [1.16-2.71], respectively). Vaccine perceptions associated with vaccine intention included "My doctor told me to get my child a COVID-19 vaccine" (2.82 [1.74-4.55]); and "I'm concerned about my child's side effects from the vaccine" (0.18 [0.12-0.26]).

CONCLUSIONS

One-third of CMC families expressed vaccine hesitation; however, constructs strongly associated with vaccination intent are potentially modifiable. Pediatrician endorsement of COVID-19 vaccination and careful counseling on side effects might be promising strategies to encourage uptake.

Comparing skin surface temperature to clinical documentation of skin warmth in emergency department patients diagnosed with cellulitis

Objective

To compare clinical documentation of skin warmth to patient report and quantitative skin surface temperatures of patients diagnosed with cellulitis in the emergency department (ED).

Methods

Adult patients (≥18 years) presenting to the ED with an acute complaint involving visible erythema of the lower extremity were prospectively enrolled. Those diagnosed with cellulitis were included in this analysis. Participant report of skin warmth was recorded and skin surface temperature values were obtained from the affected and corresponding unaffected area of skin using thermal cameras. Average temperature (Tavg) was extracted from each image and the difference in Tavg between the affected and unaffected limb was calculated (Tgradient). Clinical documentation of skin warmth was compared to patient report and measured skin warmth (Tgradient >0°C).

Results

Among 126 participants diagnosed with cellulitis, 110 (87%) exhibited objective warmth (Tgradient >0°C) and 58 (53%) of these cases had warmth documented in the physical examination. Of those with objective warmth, 86 (78%) self-reported warmth and 7 (6%) had warmth documented in their history of present illness (HPI) (difference = 72%, 95% confidence interval [CI]: 62%-82%; P < 0.001). A significant difference was observed for Tavg affected when warmth was documented (32.1°C) versus not documented (31.0°C) in the physical examination (difference = 1.1°C, 95% CI: 0.29-1.94; P = 0.0083). No association was found between Tgradient and patient-reported or HPI-documented warmth.

Conclusions

The majority of ED-diagnosed cellulitis exhibited objective warmth, yet significant discordance was observed between patient-reported, clinician-documented, and measured warmth. This raises concerns over inadequate documentation practices and/or the poor sensitivity of touch as a reliable means to assess skin surface temperature. Introduction of objective temperature measurement tools could reduce subjectivity in the assessment of warmth in patients with suspected cellulitis.

Clinical Manifestations and Outcomes in Immunocompetent and Immunocompromised Patients With Blastomycosis

BACKGROUND

Blastomyces is a dimorphic fungus that infects persons with or without underlying immunocompromise. To date, no study has compared the clinical features and outcomes of blastomycosis between immunocompromised and immunocompetent persons.

METHODS

A retrospective study of adult patients with proven blastomycosis from 2004-2016 was conducted at the University of Wisconsin. Epidemiology, clinical features, and outcomes were analyzed among solid-organ transplantation (SOT) recipients, persons with non-SOT immunocompromise (non-SOT IC), and persons with no immunocompromise (NIC).

RESULTS

A total of 106 cases met the inclusion criteria including 74 NIC, 19 SOT, and 13 non-SOT IC (malignancy, HIV/AIDS, idiopathic CD4+ lymphopenia). The majority of patients (61.3%) had at least 1 epidemiologic risk factor for acquisition of Blastomyces. Pneumonia was the most common manifestation in all groups; however, immunocompromised patients had higher rates of acute pulmonary disease (P = .03), more severe infection (P = .007), respiratory failure (P = .010), and increased mortality (P = .02). Receipt of SOT primarily accounted for increased severity, respiratory failure, and mortality in immunosuppressed patients. SOT recipients had an 18-fold higher annual incidence of blastomycosis than the general population. The rate of disseminated blastomycosis was similar among NIC, SOT, and non-SOT IC. Relapse rates were low (5.3-7.7%).

CONCLUSIONS

Immunosuppression had implications regarding the acuity, severity, and respiratory failure. The rate of dissemination was similar across the immunologic spectrum, which is in sharp contrast to other endemic fungi. This suggests that pathogen-related factors have a greater influence on dissemination for blastomycosis than immune defense.

Urine Antigen Testing is Equally Sensitive to B. dermatitidis and B. gilchristii Infections

INTRODUCTION

Blastomycosis is endemic in Wisconsin with Blastomyces dermatitidis and B. gilchristii responsible for infections. Urine antigen testing is a non-invasive diagnostic method for blastomycosis with up to 93% test sensitivity. However, the test's sensitivity has not been evaluated with relationship to B. gilchristii infections.

METHODS

We aimed to assess physician use of the urine antigen assay and its sensitivity to B. gilchristii and B. dermatitidis infections in a retrospective study. Culture confirmed clinical cases of blastomycosis from 2008-2016 were identified within Marshfield Clinic Health System (MCHS) and UW Hospital and Clinics (UWHC) medical records. Clinical data were abstracted from each medical record and included the following: patient demographics, presence of immune compromising and underlying medical conditions, treatment drugs, presence of isolated pulmonary or disseminated disease, death, urine antigen testing, timeframe of testing, and quantitative test values (EIA units or ng/mL).

RESULTS

A total of 140 blastomycosis cases were included in this study, with MCHS contributing 114 cases to the study and UWHC contributing 26 cases. The majority of UWHC cases (n=22; 85%) were caused by B. dermatitidis and the majority of MCHS cases (n=73; 64%) were caused by B. gilchristii. UWHC physicians were significantly more likely to treat with multiple drugs during the course of infection and were more likely to prescribe amphotericin B and voriconazole. Urine antigen testing was more frequently used at UWHC (n=24; 92%) than MCHS (n=51; 45%; P < 0.00001). In this study, the urine antigen assay demonstrated 79% sensitivity. Sensitivity was significantly associated with the timeframe of testing (P < 0.05), with most true positive urine antigen tests (83%) being performed ≤ 7 days from diagnosis. In this study, the urine antigen assay was capable of detecting both B. dermatitidis and B. gilchristii at about equal sensitivity. Urine antigen concentration (ng/mL) trended higher in B. dermatitidis infections.

CONCLUSION

This study found that the urine antigen assay is capable of detecting both species of Blastomyces at about the same sensitivity. We recommend continued use of the urine antigen assay for diagnosis of blastomycosis and recommend that the assay be used early in the diagnostic process to minimize the chance of false negative results.

Immune recovery in HIV-1 infected patients with sustained viral suppression under long-term antiretroviral therapy in Ethiopia

BACKGROUND

There is very little data on long-term immune recovery responses in patients on suppressive antiretroviral therapy (ART) in the setting of sub-Saharan Africa (SSA). Thus, we sought to determine CD4+ T-cell, CD8+ T-cell and CD4/CD8 ratio responses in a cohort of HIV infected individuals on sustained suppressive ART followed up for more than a decade.

METHODS

The cohort comprised adult patients who started ART between 2001 and 2007 and followed for up to 14 years. Trends in median CD4+ T-cells, CD8+ T-cells and CD4/CD8 ratio were reviewed retrospectively. Poisson regression models were used to identify factors associated with achieving normalized T-cell biomarkers. Kaplan-Meier curves were used to estimate the probability of attaining normalized counts while on suppressive ART.

RESULTS

A total of 227 patients with a median duration of follow-up on ART of 12 (IQR: 10.5-13.0) years were included. CD4 cell count increased from baseline median of 138 cells (IQR: 70-202) to 555 cells (IQR: 417-830). CD4 cell increased continuously up until 5 years, after which it plateaued up until 14 years of follow up. Only 69.6% normalized their CD4 cell count within a median of 6.5 (IQR: 3.0-10.5) years. In addition, only 15.9% of the cohort were able to achieve the median reference CD4+ T-cell threshold count in Ethiopians (≈760 cells/μL). CD8+ T-cell counts increased initially until year 1, after which continuous decrease was ascertained. CD4/CD8 ratio trend revealed continuous increase throughout the course of ART, and increased from a median baseline of 0.14 (IQR: 0.09-0.22) to a median of 0.70 (IQR: 0.42-0.95). However, only 12.3% normalized their ratio (≥ 1.0) after a median of 11.5 years. In addition, only 8.8% of the cohort were able to achieve the median reference ratio of healthy Ethiopians.

CONCLUSION

Determination of both CD4+ and CD8+ T-cells, along with CD4/CD8 ratio is highly relevant in long-term follow-up of patients to assess immune recovery. Monitoring ratio levels may serve as a better biomarker risk for disease progression among patients on long-term ART. In addition, the findings emphasize the relevance of initiation of ART at the early stage of HIV-1 infection.

Role of CD4/CD8 ratio on the incidence of tuberculosis in HIV-infected patients on antiretroviral therapy followed up for more than a decade

Background

The role of CD4/CD8 ratio on the incidence of tuberculosis (TB) in patients on antiretroviral therapy (ART) is unknown. Thus, we sought to determine whether the CD4/CD8 ratio was associated with development of TB in a cohort of HIV infected individuals on ART followed up for more than a decade in the setting of sub-Saharan Africa (SSA).

Methods

The cohort comprised adult patients who started ART between 2001 and 2007 and followed for up to 15 years. Clinical data were collected in retrospective manner. Patients with an AIDS defining illness or a CD4 count <200 cell/μL were started with a combination of ART. The participants have clinic visits every 6 months and/or as needed. Poisson regression models were used to identify factors associated with development of incident TB. Kaplan-Meier curves were used to estimate the probability of incident TB while on ART.

Results

A total of 347 patients with a median duration of follow-up on ART of 11.5 (IQR: 10.0–12.5) years were included. Incident TB developed in 47 patients during the 3259 person-years of follow-up, the majority (76.6%) occurred within five year of ART initiation. On univariate analysis, poor ART adherence (RR:2.57, 95% CI: 1.28–5.17), time-updated CD4 cell count of lower than 200 (RR: 4.86, 95%CI 2.33–10.15), or CD4 cell count between 200 and 500 (RR: 4.68, 95% CI: 2.17–10.09), time-updated CD8 cell count lower than 500 (RR: 2.83 95% CI 1.31–6.10), or CD8 cell count over 1000 (RR: 2.23, 95% CI: 1.12–4.45), time-updated CD4/CD8 ratio of less than 0.30 (RR: 6.00, 95% CI: 2.96–12.14), lack of normalization of CD4 T-cell count (RR: 6.13, 95% CI: 2.20–17.07), and virological failure (RR: 2.35 (95% CI: 1.17–4.71) were all associated with increased risk of incident TB. In multivariate analysis, however, time-updated CD4/CD8 ratio of less than 0.30 (adjusted RR: 4.08, 95% CI: 1.31–12.68) was the only factor associated with increased risk of developing incident TB (p = 0.015). Similar results were obtained in a sensitivity analysis by including only those virally suppressed patients (n = 233, 69% of all patients). In this group, CD4/CD8 ratio of less than 0.30 was associated with development of incident TB (adjusted RR: 4.02, 95% CI: 1.14–14.19, p = 0.031). Overall, the incidence rate of TB in patients with an updated CD4/CD8 ratio of less than 0.30 was more than 5-fold higher when compared with those with a ratio more than 0.45.

Conclusion

Low CD4/CD8 ratio is independently associated with an increased risk of incident TB despite viral suppression. CD4/CD8 ratio may serve as a biomarker for identifying patients at risk of TB in patients on ART in the setting of SSA.

Turning on virulence: Mechanisms that underpin the morphologic transition and pathogenicity of Blastomyces

This review article focuses on the mechanisms underlying temperature adaptation and virulence of the etiologic agents of blastomycosis, Blastomyces dermatitidis, Blastomyces gilchristii, and Blastomyces percursus. In response to temperature, Blastomyces undergoes a reversible morphologic switch between hyphae and yeast known as the phase transition. The conversion to yeast for Blastomyces and related thermally dimorphic fungi is essential for virulence. In the yeast phase, Blastomyces upregulates the essential virulence factor, BAD1, which promotes attachment to host cells, impairs activation of immune cells, and blunts cytokine release. Blastomyces yeast also secrete dipeptidyl-peptidase IVA (DPPIVA), a serine protease that blunts the action of cytokines released from host immune cells. In vivo transcriptional profiling of Blastomyces yeast has uncovered genes such as PRA1 and ZRT1 involved in zinc scavenging that contribute to virulence during murine pulmonary infection. The discovery and characterization of genes important for virulence has led to advances at the bedside regarding novel diagnostics, vaccine development, and new targets for drug discovery.

The Shock of Strep: Rapid Deaths Due to Group a Streptococcus

Streptococcus pyogenes, also known as group A beta-hemolytic strep, is a Gram positive coccus responsible for several million infections every year. The types of infections vary widely from pharyngitis to myositis, but all can advance to severe life threatening invasive disease. Of those infected, approximately 1100 to 1600 people die each year due to invasive disease. Why certain individuals contract severe infections is not known, but many strains of Streptococcus pyogenes are known to produce toxins and superantigens. Invasive Streptococcus pyogenes infections have been shown to cause significant morbidity and rapid mortality. In many cases, patients expire before full antemortem testing can be performed, causing physicians and families to look to forensic pathologists for answers. Understanding the pathogenesis of invasive group A strep infections, relevant gross and microscopic findings, and proper culturing techniques is critical for forensic pathologists to diagnosis this condition and assist in the education and protection of the communities they serve.

Clinical Manifestations and Treatment of Blastomycosis

The causal agents of blastomycosis, Blastomyces dermatitidis and Blastomyces gilchristii, belong to a group of thermally dimorphic fungi that can infect healthy and immunocompromised individuals. Following inhalation of mycelial fragments and spores into the lungs, Blastomyces spp convert into pathogenic yeast and evade host immune defenses to cause pneumonia and disseminated disease. The clinical spectrum of pulmonary blastomycosis is diverse. The diagnosis of blastomycosis requires a high degree of clinical suspicion and involves culture-based and non-culture-based fungal diagnostic tests. The site and severity of infection, and the presence of underlying immunosuppression or pregnancy, influence the selection of antifungal therapy.

Readability, credibility and quality of patient information for hypogonadism and testosterone replacement therapy on the Internet

The incidence of hypogonadism and use of testosterone replacement therapy (TRT) are rising, while data evaluating the complexity and quality of health-care information available to patients on the Internet for hypogonadism or TRT are lacking. This study focuses on characterizing the readability, credibility and quality of patient-centered information for hypogonadism on the Internet. A Google search was performed to identify top-ranked websites offering patient-centered information on hypogonadism and TRT. Readability was quantified by reading grade level using several validated instruments. Credibility and quality were determined by several additional criteria, including authorship, references, health-care information quality certification and breadth of topic discussion. Twenty of 75 total sites identified (27%) met the inclusion and exclusion criteria and were evaluated. The mean reading grade level was 13.1 (interquartile range 11.7-15.1), with all websites demonstrating reading levels significantly above recommended levels. Less than half (45%) of the sites were neither authored nor reviewed by a physician, 60% contained at least one reference and 40% were certified for displaying quality health-care information. Over half (55%) did not comprehensively discuss management of hypogonadism or mention treatment-associated risks. In conclusion, the majority of patient-centered information available on the Internet regarding hypogonadism or TRT is of poor quality and too complex for the average patient to comprehend. These results highlight a critical shortage in easily accessible, high-quality, comprehensible online patient health-care information on hypogonadism and TRT.

The Association Between Geographic Density of Infectious Disease Physicians and Limb Preservation in Patients With Diabetic Foot Ulcers

Background

Avoiding major (above-ankle) amputation in patients with diabetic foot ulcers is best accomplished by multidisciplinary care teams with access to infectious disease specialists. However, access to infectious disease physicians is partially influenced by geography. We assessed the effect of living in a hospital referral region with a high geographic density of infectious disease physicians on major amputation for patients with diabetic foot ulcers. We studied geographic density, rather than infectious disease consultation, to capture both the direct and indirect (eg, informal consultation) effects of access to these providers on major amputation.

Methods

We used a national retrospective cohort of 56440 Medicare enrollees with incident diabetic foot ulcers. Cox proportional hazard models were used to assess the relationship between infectious disease physician density and major amputation, while controlling for patient demographics, comorbidities, and ulcer severity.

Results

Living in hospital referral regions with high geographic density of infectious disease physicians was associated with a reduced risk of major amputation after controlling for demographics, comorbidities, and ulcer severity (hazard ratio, .83; 95% confidence interval, .75–.91; P < .001). The relationship between the geographic density of infectious disease physicians and major amputation was not different based on ulcer severity and was maintained when adjusting for socioeconomic factors and modeling amputation-free survival.

Conclusions

Infectious disease physicians may play an important role in limb salvage. Future studies should explore whether improved access to infectious disease physicians results in fewer major amputations.

Demonstration of ignition radiation temperatures in indirect-drive inertial confinement fusion hohlraums

We demonstrate the hohlraum radiation temperature and symmetry required for ignition-scale inertial confinement fusion capsule implosions. Cryogenic gas-filled hohlraums with 2.2 mm-diameter capsules are heated with unprecedented laser energies of 1.2 MJ delivered by 192 ultraviolet laser beams on the National Ignition Facility. Laser backscatter measurements show that these hohlraums absorb 87% to 91% of the incident laser power resulting in peak radiation temperatures of T(RAD)=300 eV and a symmetric implosion to a 100 μm diameter hot core.

Economic evaluation of recombinant human copper zinc superoxide dismutase administered at birth to premature infants

OBJECTIVE

To determine the cost-effectiveness of recombinant human superoxide dismutase (rhSOD) in the prevention of chronic respiratory morbidity, defined as use of respiratory medications, in preterm infants.

STUDY DESIGN

This retrospective economic evaluation was undertaken using data from a previously published randomized controlled trial of the use of rhSOD in neonates of birthweight 600 to 1200 g. This ancillary study measured all relevant direct medical costs from birth to 1 year corrected age using resource data collected for infants from the clinical trial. Unit costs were derived from secondary datasets in similar populations, stratified by level of care or diagnosis. All costs were expressed in 2003 US dollars.

RESULT

rhSOD was associated with a highly favorable incremental cost of only $378 per chronic respiratory morbidity averted at 1 year corrected age. There was a 95% probability that the therapy would be considered cost-effective if a decision maker was willing to pay $7000 to avert one infant with long-term significant respiratory illness, and a 52% probability that it would actually reduce costs while improving outcomes. These results were more pronounced among infants <27 weeks gestational age at birth.

CONCLUSION

Based on resource data from a single randomized trial, this retrospective analysis supports the potential economic desirability of rhSOD treatment in this population.

Novel 5' exonuclease-based real-time PCR assay for the detection of t(14;18)(q32;q21) in patients with follicular lymphoma

The exonuclease-based real-time polymerase chain reaction (PCR) exploits 5'-->3' exonuclease activity of Taq polymerase and measures PCR product accumulation as the reaction proceeds through a dual-labeled fluorogenic probe. The utility of this exonuclease-based PCR assay as a rapid alternative to conventional PCR for follicular lymphoma-associated t(14;18)(q32;q21) was evaluated in this study. The specificity of the assay for t(14;18) involving bcl-2 and immunoglobulin heavy-chain joining region (JH) genes was assessed by analyzing DNA from 53 patients (38 B-cell non-Hodgkin's lymphomas and 15 nonneoplastic proliferations) and correlating the exonuclease PCR data with conventional PCR results. bcl-2/JH fusion sequences were detected by exonuclease-based PCR in 24 of 25 cases shown to be bcl-2 rearranged by conventional PCR. Fusion sequences were not detected in patients who were negative by conventional PCR. The overall concordance between the two assays was 98% (52 of 53 cases concordant positive or negative). In a serial dilution study using t(14;18)-positive cell line DNA, exonuclease-based PCR detected fusion sequences at DNA concentrations of 5 pg, equivalent to 0.6 to 0.8 genomes per reaction. Thus, this study demonstrated that exonuclease-based PCR for t(14;18) is both specific and highly sensitive. The elimination of the post-PCR amplicon detection steps and the ability to quantitate the input target DNA sequences make this assay ideal for routine diagnostics and monitoring minimal residual disease.

Morphology of acute promyelocytic leukemia with cytogenetic or molecular evidence for the diagnosis: characterization of additional microgranular variants

Early diagnosis of t(15;17) acute promyelocytic leukemia (APL) is essential because of the associated disseminated intravascular coagulation and the unique response of the disease to all-trans retinoic acid (ATRA) therapy. Early diagnosis depends primarily on morphological recognition. The French-American-British (FAB) classification, however, does not describe all morphological variations that occur in APL. In 25 cases with evidence of APL confirmed by cytogenetic and/or molecular analysis, we found a heterogeneous morphological group. The most common form of APL was heterogeneous and consisted of various combinations of cells in which hypergranular cells and some cells with multiple Auer rods were obvious. In some cases, one cell predominated. This led to the description of five subcategories. These included the classical FAB M3 with hypergranular cells and multiple Auer rods; the FAB variant with hypogranular bilobed cells; the basophilic cell type of McKenna et al. [Br. J. Haematol 50:201, 1982]; and two additional subtypes, one consisting of differentiated promyelocytes and a few blast cells (M2-like), and the other consisting largely of blast cells and a few early promyelocytes (M1-like). Immunophenotyping revealed a pattern of CD33 and/or CD13 positivity, and CD14 and HLA-DR negativity in 96% of cases. CD2 was positive in the FAB variant and in the subtype with basophilic cells, but negative with other subtypes. Three out of five cases with basophilic cell predominance [McKenna et al.: Br J Haematol 50:201, 1982], and one out of two M2-like cases, responded to ATRA therapy. Awareness of the heterogeneity and the atypical morphologic subtypes found in t(15;17) APL will contribute to improved recognition and early institution of ATRA therapy.

The application of fluorescence-based PCR and PCR-SSCP to monitor the clonal relationship of cells bearing the t(14;18)(q32;q21) in sequential biopsy specimens from patients with follicle center cell lymphoma

This study evaluates the utility of fluorescence-based polymerase chain reaction (PCR) and PCR-SSCP methodologies to monitor the clonal relatedness of cells with bcl-2 major break point region (mbr)/JR fusion sequences in sequential samples from patients with follicular lymphoma (FL). Fluorescence-tagged PCR products from 2-4 sequential samples from seven FL patients were resolved in acrylamide gels and analyzed on an Applied Biosystems' automated DNA sequencer equipped with Genescan software. The amplicons were sequenced directly using automated DNA sequencing to obtain the precise amplicon size and base sequence. Fluorescence-based PCR-single-strand conformation polymorphism (SSCP) analysis performed to distinguish amplicons of similar size but of different base sequence. Amplification products differing by as few as 5 bp resolved clearly under fluorescent PCR assay conditions making possible by visual inspection alone the distinction of two products that otherwise appeared to be of similar size by conventional gel electrophoretic methods. The size of the amplicons as determined by Genescan software correlated exactly with the sizes generated by sequence analysis confirming the precision and accuracy of the fluorescent PCR assay. Under nondenaturing conditions, the mobility profiles of the amplicons from sequential samples with identical base sequence remained indistinguishable, whereas amplicons of similar size but of dissimilar base sequence from different patients exhibited distinct migration patterns. Thus, this study demonstrates that a combination of fluorescent PCR and PCR-SSCP assays for the detection of the t(14;18) provides an accurate measure of clonal relationship based on molecular size and sequence similarities without involving radiolabeling and sequencing strategies. Furthermore, the demonstrated preservation of junctional sequences across sequential biopsy specimens validates the use of PCR in the monitoring of minimal residual disease and eliminates concern about the detection of secondary, non-tumor-related translocations.

Long-range amplification of genomic DNA detects the t(2;5)(p23;q35) in anaplastic large-cell lymphoma, but not in other non-Hodgkin's lymphomas, Hodgkin's disease, or lymphomatoid papulosis

DESIGN

Determine the frequency of t(2;5)(p23;q35) in anaplastic large-cell lymphoma (ALCL), non-Hodgkin's lymphoma (NHL), Hodgkin's disease (HD), and lymphomatoid papulosis (LP).

PATIENTS AND METHODS

The t(2;5) was detected with a long-range nested polymerase chain reaction (PCR) using 0.5 microgram of DNA (60,000-80,000 cells), 5'-primers from the NPM gene, 3'-primers from the ALK gene, agarose electrophoresis, hybridization, and autoradiography. Patients were evaluable if a 3016 base pair amplicon could be generated from tumor DNA with beta-globin primers.

RESULTS

Amplicons were detected by PCR of genomic DNA from three ALCL cell lines and four primary ALCLs known to t(2;5) positive. DNA from t(2;5)-positive cell lines diluted 10(4)-fold or 10(5)-fold generated amplicons in 100% or 20% of reactions, respectively. Archival tumor DNA from 144 patients was amplifiable by beta-globin amplicons in 126 (88%) who are considered evaluable for this study. Twenty-two had ALCL, 69 other NHLs, 30 HD, and five LP. Genomic DNA PCR detected the t(2;5) in 5 of 22 with ALCL (23%, 95% confidence intervals [95% CI] 8%-45%) but not in those with NHLs, HD, or LP. Among ALCLs the t(2;5) was confined to 5 of 20 with nodal presentations (25%, 95% CI 9%-49%), among whom it was seen in 5 of 15 with T-cell or null-cell phenotype (33%, 95% CI 12%-62%), in 4 of 11 with age < 40 years (36%, 95% CI 11%-69%), and in 4 of 9 with nodal presentations, T-cell or null-cell phenotype, and age < 40 years (44%, 95% CI 14%-79%). Amplicon sizes were different between cell lines and patients, reflecting unique genomic DNA breakpoints, as confirmed by DNA sequencing, and served as an internal control against specimen cross-contamination in the laboratory.

CONCLUSIONS

Long-range PCR of genomic DNA detects t(2;5) only in ALCL, but not in other NHLs, HD, or LP. Long-range PCR may be useful in establishing diagnosis, determining prognosis, and monitoring minimal residual disease in ALCL.

Amplification of genomic DNA demonstrates the presence of the t(2;5) (p23;q35) in anaplastic large cell lymphoma, but not in other non-Hodgkin's lymphomas, Hodgkin's disease, or lymphomatoid papulosis

Anaplastic large cell lymphoma (ALCL) is a distinct clinicopathologic variant of intermediate grade non-Hodgkin's lymphomas (NHL) composed of large pleomorphic cells that usually express the CD30 antigen and interleukin (IL)-2 receptors, and is characterized by frequent cutaneous and extranodal involvement. With variable frequency ALCL bear the t(2;5)(p23;q35) chromosomal translocation that fuses the nucleophosmin (NPM) gene on chromosome 5q35 to a novel protein kinase gene, Anaplastic Lymphoma Kinase (ALK), on chromosome 2p23. We determined the frequency of this translocation with a novel DNA polymerase chain reaction (PCR) technique using 0.5 microgram of genomic DNA, 5'-primers derived from the NPM gene and 3'-primers derived from the ALK gene and hybridization with internal probes. The presence of amplifiable DNA in the samples was tested with the inclusion in the PCR reaction of oligonucleotide primers designed to amplify a 3016-bp fragment from the beta-globin locus. NMP-ALK fusion amplicons were detected using DNA isolated either from all three ALCL cell lines tested, or from all four primary ALCL tumors known to contain the t(2;5)(p23;q35) translocation. Nested amplicons were detected by hybridization in 100% of specimens diluted 10(4)-fold and in 20% of those diluted 10(5)-fold. We subsequently examined archival genomic DNA from 20 patients with ALCL, 39 with diffuse large cell, 2 with mantle cell, 20 with peripheral T cell, 13 with low-grade NHL, 31 with Hodgkin's disease (HD), and 6 with lymphomatoid papulosis. Fusion of the NPM and ALK genes was detected in three of 18 patients with ALCL who had amplifiable DNA (17%, 95% confidence intervals 4% to 41%), but not in any patients with other NHL, HD, or lymphomatoid papulosis. The amplicon sizes were different in all cell lines and patients reflecting unique genomic DNA breakpoints. We conclude that with genomic DNA-PCR the rearrangement of the NPM and ALK loci is restricted to patients with ALCL. Further studies are needed to determine the prognostic significance of the NPM-ALK rearrangement, to determine whether its detection can aid in the differential diagnosis between ALCL. Hodgkin's disease, and lymphomatoid papulosis, and to establish the usefulness of the genomic DNA PCR in the monitoring of minimal residual disease in those patients whose tumors bear the t(2;5).

T-cell-rich B large-cell lymphoma simulating lymphocyte-rich Hodgkin's disease

Immunophenotypic analysis of 50 cases fulfilling the histologic criteria for mixed cellularity Hodgkin's disease disclosed nine cases with a B-cell, non-Hodgkin's phenotype (CD20+, CD15-, CD30-, EMA-). The cases were characterized by a diffuse small lymphocytic milieu, interspersed atypical large cells including classic Reed-Sternberg cells, and infrequent plasma cells, eosinophils, and L&H cells. The male:female ratio was 7:2 (aged 22-65 years, median 39 years). Three patients were Ann Arbor stage II, two stage III, and four stage IV. The patients presented with generalized lymphadenopathy (four), mesenteric lymph node involvement (two), splenomegaly (four), and bone marrow involvement (three). Four patients were treated with standard Hodgkin's disease protocols. Two attained a complete response and two a partial response; all relapsed and died. Four of five patients treated for large-cell lymphoma achieved a complete response and are currently alive without evidence of disease. The one patient with an initial partial response relapsed and died. We conclude that immunophenotypic analysis is essential in cases of histologic mixed cellularity Hodgkin's disease, especially in those with lymphocyte-rich morphology. Cases with a B-cell phenotype should be diagnosed and treated as T-cell-rich B large-cell lymphoma.

A prospective study to determine the frequency and clinical significance of alloimmunization post-transfusion

There is debate in the literature about the frequency and importance of delayed transfusion reactions. This uncertainty could reflect the endpoints used (clinical or serological) and the type of study (typically retrospective or case series). In this report we describe a prospective investigation to determine the frequency of alloimmunization post transfusion and whether the alloantibody production is a laboratory event or has clinical relevance. A total of 2490 patients were transfused 11,218 red cell concentrates. One or more blood samples were collected within 7 d post transfusion and screened for serological evidence of alloimmunization. If any antibody was detected the patient's post-transfusion sample was screened for biochemical evidence of haemolysis and the patient's chart reviewed for documentation of clinical signs of a transfusion reaction. Post transfusion alloimmunization occurred in 2.6% of the patients (95% CI 2.1-3.6%), who had no detectable alloantibody in pre-transfusion testing. For those 86 patients (3.5%) with alloantibodies detectable pretransfusion, 8.9% (95% CI 3.6-17.4%) developed additional aloantibodies. The most common alloantibodies detected were anti-Jka, anti-E and anti-K. Despite the high frequency of serological evidence of delayed transfusion reactions, only one patient (0.05%) had clinical evidence of a delayed haemolytic transfusion reaction (95% CI 0.0-0.27%). Serological evidence of a delayed transfusion reaction is common; however, these reactions rarely cause clinical symptoms.

An examination of the phenomenology and the reliability of ratings of compulsive behavior in autism

To clarify the nature of compulsive behavior in autism, staff reports of behavioral patterns of 17 young autistic adults living in a farmstead residential facility were analyzed. Three staff members, who had worked most closely with each resident for at least 3 months completed three questionnaires, including Quantitative and Qualitative compulsive behavior scales, and the Childhood Autism Rating Scale (CARS). The questionnaires were completed on two occasions with a 2-week interval between administrations. Test-retest and interrater consistencies were examined for each of the scales. Both the Qualitative and Quantitative questionnaires show promise as instruments that could be used as objective baselines or descriptors for compulsive behavior in autism. Information gathered from these scales could be utilized to determine how to intervene in the behavior, and to assess progress in treatment programs.

Asynchronous pulmonary hyperplasia associated with tracheal atresia: pathologic and prenatal sonographic findings

We describe a case of pulmonary hyperplasia associated with tracheal atresia and a complete obstruction to the egress of pulmonary secretions. In classical pulmonary hyperplasia associated with cartilagenous laryngeal atresia and a persistent pharyngotracheal duct, the histologic appearance of the lungs is normal but exhibits "synchronous" hypermaturity. The histologic pattern in our case is much less mature, resembles CAM type III, and exhibits "asynchronous" development. We suggest that these histologic patterns be distinguished and that pulmonary hyperplasia is probably underrecognized and not nearly as rare as previously thought.

Chemiluminescence receptor assay for measuring vitamin B12 in serum evaluated

We evaluated a chemiluminescence receptor assay for vitamin B12 in serum (Magic Lite; Ciba Corning Diagnostics), in which an acridinium ester label is used with magnetic particle separation. Within- and between-batch precisions were generally acceptable, except at low analyte concentrations. The reference range determined from 104 elective preoperative patients was 120-610 pmol/L, compared with 150-590 pmol/L for our in-house radioligand-binding assay. Magic Lite discriminated between normal and abnormal results as effectively as the in-house method when local reference ranges were applied. Magic Lite demonstrated a negative bias at low analyte concentrations and was unable to detect any vitamin B12 in two B12-deficient patients. Assay accuracy--judged from analytical recovery and comparisons with the in-house method and two other radioassay kits (Quantaphase, Bio-Rad Labs., and Immophase, Ciba Corning Diagnostics)--was poor at low B12 concentrations when the manufacturer's recommended two-point calibration was used. This problem was partially corrected by using a full set of calibrators.

Chemiluminescence receptor assay for measuring vitamin B12 in serum evaluated

We evaluated a chemiluminescence receptor assay for vitamin B12 in serum (Magic Lite; Ciba Corning Diagnostics), in which an acridinium ester label is used with magnetic particle separation. Within- and between-batch precisions were generally acceptable, except at low analyte concentrations. The reference range determined from 104 elective preoperative patients was 120-610 pmol/L, compared with 150-590 pmol/L for our in-house radioligand-binding assay. Magic Lite discriminated between normal and abnormal results as effectively as the in-house method when local reference ranges were applied. Magic Lite demonstrated a negative bias at low analyte concentrations and was unable to detect any vitamin B12 in two B12-deficient patients. Assay accuracy--judged from analytical recovery and comparisons with the in-house method and two other radioassay kits (Quantaphase, Bio-Rad Labs., and Immophase, Ciba Corning Diagnostics)--was poor at low B12 concentrations when the manufacturer's recommended two-point calibration was used. This problem was partially corrected by using a full set of calibrators.

Reinduction of remission of chronic myeloid leukemia by donor leukocyte transfusion following relapse after bone marrow transplantation: recovery complicated by initial pancytopenia and late dermatomyositis

A significant proportion of patients relapse after allogeneic BMT for CML. These relapses have been treated by induction of a graft-versus-leukemia effect by transfusing donor leukocytes. We have treated a 27-year-old woman with interferon and donor leukocyte transfusion and a complete haematological and cytogenetic remission was obtained coincident with the onset of GVHD. Her course was complicated by prolonged and profound pancytopenia which was fully reversed by the administration of rGM-CSF. She remains in CR with mild dermatomyositis due to chronic GVHD 17 months after the procedure.

Evaluation of commercial blood-containing media for cultivation of Mycobacterium haemophilum

Mycobacterium haemophilum requires hemin for growth, and thus it is unlikely to be isolated by current routine methods. This study evaluated growth of M. haemophilum on commercially available blood agar and on different basal media and with other sources of hemin. The effect of dyes, crystal violet and malachite green, in controlling contamination was tested. Results showed that although M. haemophilum can grow on a variety of commercially prepared blood agars, contamination is a significant deterrent. Both malachite green and crystal violet inhibited the growth of contaminants without affecting the growth of M. haemophilum. The following medium (MMV: McBride's Mycobacterium Haemophilum) is recommended: Casman's blood agar base containing 5% sheep blood heated and 5 micrograms/mL crystal violet, prepared in screw-topped vials, tightly capped and incubated at 30 degrees C under atmospheric conditions.

A prospective study to determine the safety of omitting the antiglobulin crossmatch from pretransfusion testing

Transfusion medicine laboratories routinely perform a series of pretransfusion serological tests including: ABO grouping, Rh typing, and investigation of the recipient's serum to detect antibodies against blood group antigens (antibody screen). As a final check, most laboratories also perform a crossmatch in which the recipient's serum is incubated with the donor's red cells followed by the addition of an antiglobulin reagent (antiglobulin crossmatch). The need for the antiglobulin crossmatch when the antibody screen is negative has been questioned because there are few antibodies that are detected by this test. Such antibodies are usually directed against low incidence antigens that are not expressed on the screening cells and in many cases the clinical importance of these antibodies is uncertain. For these reasons, we performed a prospective study in which patients requiring red cell transfusion had a group and screen performed. If the antibody screen was negative the antiglobulin crossmatch was omitted. Following the transfusion of the blood, the antiglobulin crossmatch was performed to look for any potential incompatibility. All patients were monitored both serologically and clinically. Over the 2-year interval of the study 9128 patients were entered. There were 8936 patients (97.9%) with a negative antibody screen and 26.9% (2404 patients) were transfused a total of 10,899 red cell concentrates. The antiglobulin crossmatch performed after the transfusion indicated that 168 red cell concentrates (1.5%) would have been incompatible if the antiglobulin crossmatch had been performed pretransfusion. These 168 red cell concentrates were transfused to 119 patients during 130 transfusion episodes (defined as all transfusions administered within 24 h). Of the 130 transfusion episodes, 79.2% (103/130) were false positive laboratory results. There were 27 transfusion episodes where the antiglobulin crossmatch on blood transfused was positive due to an IgG antibody. Even though these transfused red cell concentrates were designated incompatible by the antiglobulin crossmatch, none of the patients receiving this blood had clinical or serological evidence of haemolysis. We concluded that the antiglobulin phase of the crossmatch can be omitted from pretransfusion testing without putting patients at risk.

A pilot study of carboplatin augmentation therapy for patients with poor risk acute non-lymphocytic leukemia

Eleven patients with acute non-lymphocytic leukemia and persistent leukemia on a bone marrow done 6 days after the start of standard induction chemotherapy with daunorubicin and cytosine arabinoside were given augmentation chemotherapy with carboplatin as a continuous intravenous infusion over 3 days. Nine of the 11 patients (82%) entered complete remission. The hematologic and non-hematologic toxicities encountered by these patients were similar to those seen after conventional therapy alone with the exception of peripheral neuropathy in one patient. Of the two induction failures, one patient died of treatment-related toxicity and one patient had resistant leukemia.

Congenital hepatoblastoma and Beckwith-Wiedemann syndrome: a case study including DNA ploidy profiles of tumor and adrenal cytomegaly

A case of fatal congenital hepatoblastoma is described in which the autopsy provided the first evidence of Beckwith-Wiedemann syndrome. Aneuploid quantitative DNA patterns were found by image analysis of the tumor and the cytomegalic adrenal gland.

Classifying acute leukemia by immunophenotyping: a combined FAB-immunologic classification of AML

A panel of commercially available monoclonal antibodies and five heteroantisera were used to distinguish and subtype 138 cases of acute leukemia (AL). The immunophenotype was compared with the French-American-British (FAB) classification obtained on the cases. The immunophenotype discriminated acute myelogenous leukemia (AML) from acute lymphoblastic leukemia (ALL) and recognized cases not distinguished by cytochemistry (22% of cases), mixed lineage phenotypes (13% of cases), and cases with separate populations of lymphoblasts and myeloblasts (one case). Using the immunologic panel and derived criteria to subtype AML, correspondence of the immunophenotype to the FAB subtypes M1, M2, M4, and M5 was possible in greater than 80% of cases. A combined classification of the immunophenotype and FAB morphology/cytochemistry was devised for AML subtyping. It is recommended that immunophenotyping should be done at least in all cases with negative or inconclusive cytochemistry. At present, we suggest that until a "gold standard" for identifying leukemic subtypes is developed, the best method for typing acute leukemia is by using a combination of morphology, cytochemistry and immunophenotyping.

Rhesus alloimmunization following intensive plasma exchange

A 17-year-old woman was admitted to the hospital for the treatment of rapidly progressive systemic lupus erythematosus. She failed to improve when treatment with cyclophosphamide and prednisone and, therefore, was treated with intensive plasma exchange. A total of 24 liters of plasma was exchanged during six separate procedures over an 8-day period. The patient, who was blood group B Rh negative (Cde/cde), was found to have an IgG anti-D antibody reacting at a titer of 16 by the indirect antiglobulin technique 6 weeks after the first plasma exchange procedure. The titer of this antibody subsequently rose to 512. This patient, who had neither been pregnant nor received any blood products other than the plasma used during the plasma exchange, was presumably immunized by Rh positive red cells or stroma present in the transfused plasma. It is estimated that the patient received approximately 10(10) Rh positive cells, or approximately one ml of packed red cells--a quantity sufficient to cause Rhesus alloimmunization.

Collection of erythroid progenitor cells by cytapheresis of peripheral blood of normal donors

Human peripheral blood may be an alternative to bone marrow as a source of cells for hemopoietic engraftment. The ability to collect large numbers of circulating granulocyte-macrophage progenitors provides support for this contention. In the present study of cells from normal granulocyte donors, the cell concentrates obtained by cytapheresis were shown to contain even greater numbers of primitive erythroid precursors (153-956 [median 647] per 10(6) mononuclear cells) than would be predicted from the peripheral blood mononuclear cell counts. Moreover, the number of primitive erythroid precursors harvested correlated significantly with the number of granulocyte-macrophage progenitors obtained and with the total lymphocyte collection. These observations further substantiate the validity of transplanting peripheral blood as hemopoietic tissue.

Proficiency testing in immunohaematology in Ontario, Canada, 1977-1979

An analysis of the results of a compulsory proficiency testing programme in immunohaematology is presented. Error rates have been calculated for the determination of ABO and Rh(D) groups, the direct antiglobulin test and antibody detection according to defined criteria. The introduction of proficiency testing has been associated with alterations in error rates for some determinations. An educational programme introduced for laboratories with poor performance has proved effective in improving their results in the proficiency testing programme.

A system for proficiency testing in immunohaematology

A compulsory programme of proficiency testing in immunohaematology has been conducted for the last 4 years. The collection, processing and analysis of testing data reported by participating laboratories depends on a computer-based system, which allows the generation of reports for participants and working documents essential to the functioning of a committee which supervises the operation of the programme. The options open to the committee in coping with laboratories with poor performance are summarized.

Proficiency testing in immunohematology in Ontario, Canada, 1975-1977

Since April 1975 the proficiency of laboratories in Ontario that perform immunohematology tests has been assessed. While the majority of test samples have required only ABO and Rh(D) typing, others have posed problems. The error rate in uncomplicated ABO typing was 1.3/1,000 in 17,479 tests and that in straightforward Rh(D) grouping, 6.6/1,000 in 17,757 tests. False-negative (36/1,000) and false-positive (1.4/1,000) direct antiglobulin tests occurred. Errors in detection of strong alloantibodies (e.g., anti-D) were 19.7, 10.2 and 5.1/1,000 in three test samples. A2B or A2 cells with anti-A1 in serum were sent out in two surveys; error rates in ABO interpretation were 189 and 52/1,000, respectively. Laboratories also experienced difficulty in interpreting the Rh(D) type of cells with positive antiglobulin tests. These surveys have had several effects: (1) laboratories with poor performance have been identified, (2) patterns of practice have been influenced, (3) areas of ignorance have been identified, and (4) a stimulus has been provided for continuing education in immunohematology.

Experience with an albumin-enhanced, 15-minute incubation, emergency crossmatch

During a 40-month period, an emergency crossmatch procedure using an albumin-enhanced 15 minute incubation indirect antiglobulin technique was evaluated along with a standard procedure for 2,276 patients involving 6,423 units of blood. One hundred-forty unsuspected allo-antibodies were detected during this study, of which 130 were detected by both techniques. In five instances where antibodies were not detected by the emergency technique, the antibodies were not though to be clinically significant.

Clinical significance of a high mean corpuscular volume in nonanemic patients

A prospective study of the clinical significance of macrocytosis (mean corpuscular volume 100 fL or more) was carried out for 9 months in a teaching hospital in 1975. Of the 140 patients with macrocytosis at the time of admission (0l7% of all hospital admissions) 46 (33%) had low activity of serum or erythrocyte folate, or both, and 16 (11%) had low serum vitamin B12 concentrations. Among the 78 patients with normal B12 and folate values the most commonly associated significant clinical conditions were alcoholism or hepatic disease (36 patients), malignant disease or the effects of chemotherapy (25 patients) and chronic obstructive lung disease (10 patients).

A complement independent erythropoietic inhibitor acting on the progenitor cell in refractory anemia

An erythropoietic inhibitor was detected in the serum of a patient with refractory anemia. Using an in vitro heme synthesis method, the patient's serum produced tenfold inhibition of erythropoietin-stimulated radioactive iron (Fe59) incorporation into heme of normal human marrow at 72 hours, as compared with AB serum. In a separate experiment the patient's serum produced threefold inhibition, whereas immunoglobulin G (IgG) prepared from the same serum sample produced 12-fold inhibition. To identify the site of action of the inhibitor, serum was tested in a cell culture system whereby human marrow cells, grown in a plasma clot, respond to exogenous erythropoietin with the appearance of nucleated erythroid colonies. Each colony arises from a committed erythroid progenitor. The patient's serum produced a two- or tenfold reduction in the number of colonies from normal human marrow. The effect was also demonstrated on autologous marrow obtained when the patient was in "partial clinical remission". Serum samples obtained at various times during the course of the patient's illness all demonstrated a suppressive effect on colony growth. All serums were heat-inactivated, and total hemolytic complement could not be detected in either culture system. It is concluded that the anemia is due to an inhibitor, probably of IgG class, that acts on the erythroid progenitor cell. The absence of heat-labile complement components in the culture systems suggests that the mechanism is not due to immune cytolysis.

Prevention of venous thrombosis with small, subcutaneous doses of heparin

The effect of low-dose heparin prophylaxis on venous thrombosis and bleeding after major elective surgery was studied in a prospective controlled study of 820 patients. The total incidence of venous thrombosis detected with leg-scanning using fibrinogen labeled with radioactive iodine (125I) was reduced from 16.0% in the control group to 4.2% in treated patients. More important, the incidence of popliteal or femoral vein thrombosis was reduced from 2.9% to 1.0%. Prophylaxis resulted in a slight increase in bleeding-minor wound hematoma, mean volume of blood transfused, and a post-operative hematocrit fall in treated patients. However, increased bleeding was clinically minor, and prophylaxis was well tolerated.