POS1217 ANTI-TNF THERAPY FOR IMMUNE MEDIATED INFLAMMATORY DISEASES MAY BE ASSOCIATED WITH LOWER ANTIBODY LEVELS AND VIRUS NEUTRALIZATION EFFICACY FOLLOWING SARS-CoV-2 mRNA VACCINATION

Background

The impact of immunosuppressants on COVID-19 vaccination response and durability in patients with immune-mediated inflammatory diseases (IMID) is yet to be fully characterized. Humoral response may be attenuated in these patients especially those on B cell depleting therapy and higher doses of corticosteroids, but data regarding other immunosuppressants are scarce.

Objectives

We aimed to investigate antibody and T cell responses and durability to SARS-CoV-2 mRNA vaccines (BNT162b and/or mRNA 1273) in IMID patients on immunomodulatory maintenance therapy other than B-cell depleting therapy and corticosteroids.

Methods

This prospective observational cohort study examined the immunogenicity of SARS-CoV-2 mRNA vaccines in adult patients with IMIDs (psoriatic arthritis, psoriasis, inflammatory bowel disease and rheumatoid arthritis) with or without maintenance immunosuppressive therapies (anti-TNF, methotrexate/azathioprine [MTX/AZA], anti-TNF + MTX/AZA, anti IL12/23, anti-IL-17, anti-IL23) compared to healthy controls. Automated ELISA for IgGs to spike trimer, spike receptor binding domain (RBD) and the nucleocapsid (NP) and T-cell release of 9 cytokines (IFNg, IL2, IL4, IL17A, TNF) and cytotoxic molecules (sFasL, GzmA, GzmB, Perforinin) in cell culture supernatants following stimulation with spike or NP peptide arrays were conducted at 4 time points: T1=pre vaccination, T2=median 26 days after dose 1, T3=median 16 days after dose 2 and T4=median 106 days after dose 2. Neutralization assays against four SARS-CoV-2 variants (wild type, delta, beta and gamma) were conducted at T3.

Results

We followed 150 subjects: 26 healthy controls and 124 IMID patients: 9 untreated, 44 on anti-TNF, 16 on anti-TNF with MTX/AZA, 10 on anti-IL23, 28 on anti-IL12/23, 9 on anti-IL17, 8 on MTX/AZA (Table 1). Most patients mounted antibody and T cell responses with increases from dose 1 to dose 2 (100% seroconversion at T3) and some decline by T4, with variability within groups. Antibody levels and neutralization efficacy was lower in anti-TNFgroups (anti-TNF, anti-TNF + MTX/AZA) compared to controls and waned by T4 (Figure 1). T cell responses were not consistently different between groups. Pooled data showed a higher antibody response to mRNA-1273 compared to BNT162b.

Table 1.

Baseline characteristics of study participants

Controluntreated IMIDAnti- TNFAnti- TNF +MTX/AZAAnti-IL-23Anti -IL-12/23Anti -IL-17MTX/AZAn=26n=9n=44n=16n=10n=28n=9n=8p-valueIMID*N/A IBD9301002704 Psoriasis1318122 PA0732172 AS0830010 RA1100011Age median years [IQR]36 [26-46]33 [27-41]38 [30-51]53 [44-59]48 [45-61]34 [28-47]49 [46-61]42 [31-55]<0.001^Sex male (%)16 (62)5 (56)18 (41)8 (50)5 (50)13 (46)6 (67)4 (50)0.772~BMImedian kg/m2 [IQR]25 [23-28]26 [22-27]22 [24-26]26 [24-28]27 [24-35]22 [21-24]32 [26-34]26[25-33]0.001^Vaccine interval median days [IQR]74 [35-84]54 [31-64]60 [45-69]64 [50-72]74 [35-84]62 [49-69]65 [52-75]58 [21-97]0.372^

*multiple IMIDs per patient possible

Figure 1.

Antibody responses (A) Anti spike and anti RBD IgG levels at indicated time points. Blue line represents median ratio in convalescent patients. The red line is the seropositivity threshold: the median antibody level of those that pass both a 1% false positive rate and show ≥3SD from the log means of the negative controls. (B) Relative ratio of RBD, spike and NP across time. Black and gray lines indicate median and mean values, respectively. *p≤0.05, **p≤0.01, ***p≤0.001, ****p≤0.0001

Conclusion

Following 2 doses of mRNA vaccination there is 100% seroconversion in IMID patients on maintenance therapy. Antibody levels and neutralization efficacy in anti-TNF group are lower than controls, and wane substantially by 3 months after dose 2. These findings highlight the need for third dose in patients undergoing treatment with anti-TNF therapy and continued monitoring of immunity in these patient groups, taking into consideration newer variants and additional vaccine doses.

Acknowledgements

This work was funded by a donation from Juan and Stefania Speck and by grants VR-1 172711, VS1-175545, FDN-143250, GA1- 177703 and GA2- 177716, from Canadian Institutes of Health Research and COVID Immunity task force and by Sinai Health Foundation

Disclosure of Interests

Naomi Finkelstein: None declared, Roya M. Dayam: None declared, Jaclyn Law: None declared, Rogier Goetgebuer: None declared, Gary Chao: None declared, Kento T. Abe: None declared, Mitchell Sutton: None declared, Joanne M. Stempak: None declared, Daniel Pereira: None declared, David Croitoru: None declared, Lily Acheampong: None declared, Saima Rizwan: None declared, Klaudia Rymaszewski: None declared, Raquel Milgrom: None declared, Darshini Ganatra: None declared, Nathalia V. Batista: None declared, Melanie Girard: None declared, Irene Lau: None declared, Ryan Law: None declared, Michelle Cheung: None declared, Bhavisha Rathod: None declared, Julia Kitaygorodsky: None declared, Reuben Samson: None declared, Queenie Hu: None declared, Nigil Haroon: None declared, Robert Inman Consultant of: AbbVie, Janssen, Lilly, Novartis., Grant/research support from: AbbVie, Novartis, Vincent Piguet Consultant of: AbbVie, Almirall, Celgene, Janssen, Kyowa Kirin Co. Ltd, LEO Pharma,

Novartis, Pfizer, Sanofi, UCB, and Union Therapeutic, Grant/research support from: Unrestricted educational grants from AbbVie, Bausch Health, Celgene, Janssen, LEO Pharma, Lilly, L’Oréal, NAOS, Novartis, Pfizer, Pierre-Fabre, Sandoz, and Sanofi, Mark Silverberg Speakers bureau: AbbVie, Janssen, Takeda, Pfizer, Gilead and Amgen, Consultant of: AbbVie, Janssen, Takeda, Pfizer, Gilead and Amgen, Grant/research support from: AbbVie, Janssen, Takeda, Pfizer, Gilead and Amgen, Anne-Claude Grigras: None declared, Tania H. Watts: None declared, Vinod Chandran Consultant of: AbbVie, Amgen, BMS, Eli Lilly, Janssen, Novartis, Pfizer and UCB, Grant/research support from: AbbVie, Amgen, Eli-Lilly.

A221 CROHN’S DISEASE POLYGENIC RISK SCORE IS ASSOCIATED WITH FECAL CALPROTECTIN CONCENTRATION IN ASYMPTOMATIC FIRST-DEGREE RELATIVES OF CROHN’S DISEASE PATIENTS

Background

Fecal calprotectin concentration (FC), a measure of gut inflammation is reported to be significantly higher in healthy first-degree relatives (FDR) of Crohn’s disease (CD) patients compared to healthy controls. In contrast, FC in spouses of CD patients was not significantly different from controls, suggesting that a genetic predisposition rather than a shared environmental factor affects FC.

Aims

We investigated the genetic association with FC in healthy FDRs of CD patients. Notably, these subjects are known to be enriched with CD risk alleles.

Methods

We investigated 1455 healthy Caucasian FDRs of CD patients from the GEM Project. Subjects were genotyped by HumanCoreEXOME chip and ImmunoChip platforms and then imputed by the Haplotype Reference Consortium v1.1 panel (Michigan Imputation Server). SNPs with a minor allele frequency&lt;5% were removed. FC was measured using BUHLMANN ELISA kit. Heritability was estimated using a pedigree based SOLAR program and a SNP-based GCTA software. Genome wide association of FC was tested using the GEE framework that accounts for family clusters, age, sex, first 3 genetic principal components and multiplex family status (≥2 FDRs diagnosed with CD). In addition, CD-polygenic risk scores were derived based on summary statistics and imputed SNPs from a recent GWAS by pruning and thresholding (P+T) and LDPred algorithm (PMID:31002795).

Results

Among 1455 subjects, 45.2% were male, median age was 19 years (IQR 13–26), 8.8% were from multiplex families, and median FC was 52 mg/kg (IQR 31–87; 20.8% had FC&gt;100). We estimated the heritability of FC to be 27% (27.1%, standard error=9%, p&lt;0.001 by pedigree approach; 27.9%, SE=12%, p&lt;0.001 by SNP approach). An untargeted GWAS failed to show any significant association with FC (i.e. p&lt;5x10-8). The lowest p value was obtained for rs224631 (p=5x10-7). Strikingly, an increase in CD polygenic risk scores was significantly associated with an increase of FC (p=5.2x10-5 with P+T method).

Conclusions

We demonstrate that FC concentration is a heritable trait in unaffected FDRs of CD patients. Although the association between genetic variants with FC did not reach GWAS significance, CD-polygenic risk score, which incorporates small effect size CD-associated SNPs, was significantly associated with FC concentrationin this cohort. Our results suggest that FC concentration is influenced genetically with contributions from CD-associated SNPs in unaffected FDRs of CD probands. It remains to be determined if the genetic influence to FC concentration is dependent/independent with the future development of CD.

Submitted on behalf of The CCC-GEM Project research team

Funding Agencies

CCCHelmsley Charitable Trust/ Mount Sinai Hospital Fellowship Award

A41 LOSS OF SATB2 EXPRESSION IN COLORECTAL CANCER IS ASSOCIATED WITH DURATION OF INFLAMMATORY BOWEL DISEASE

Background

Patients with inflammatory bowel disease (IBD) are at higher risk for developing colitis-associated colorectal cancer (CAC). Clinical and endoscopic features are used to stratify the risk of CAC, but new biomarkers are necessary to improve this stratification. Recent studies have shown that loss of expression of special AT-rich sequence binding protein 2 (SATB2) is frequent in CAC compared to sporadic colorectal cancer and this SATB2 status is found in pre-cancerous dysplastic lesions as well. However, the relationship of known clinical risk factors for CAC and loss of SATB2 has not been explored.

Aims

To assess the association of loss of SATB2 expression in CAC with clinical characteristics of IBD.

Methods

Patients with a known diagnosis of ileocolonic or colonic Crohn’s disease (CD), ulcerative colitis (UC), or IBD unclassified (IBDU) who underwent colectomy between October 2010 and December 2017 for CAC were included. SATB2 expression in neoplastic tissue was evaluated using immunohistochemistry (IHC), where less than 5% of tumor cells showing staining was considered loss of SATB2. Tumor grade, P53 and mismatch repair (MMR) status were assessed as well. Available clinical data such as sex, smoking status, IBD diagnosis (CD, UC or IBDU), age at IBD diagnosis, duration of IBD, extent of colitis and previous medications were collected. We used a generalized linear model to assess the association between these biomarkers and clinical data.

Results

A total of 58 patients with mean age at CAC diagnosis of 50.3 ±13 years, 27 (46%) females were analyzed. Mean IBD duration was 17.6 ±10 years and 22 (37.9%), 34 (58.6%) and 2 (3.4%) were CD, UC and IBDU, respectively. Thirty-two (55.2%) CACs had loss of SATB2 expression. There was no association between age at CAC diagnosis or grade of the tumor and loss of SATB2. However, longer duration of IBD (21.2 ± 9 years vs 13.7 ± 9 years, p = 0.01) was significantly associated with loss of SATB2. There was no association between SATB2 status and other explored clinical or endoscopic variables. Tumors with P53 mutation were associated with a younger age at diagnosis of CAC (47.2 ±13 vs 55.0 ±12 years, p = 0.03), but no other associations of this marker or MMR with clinical or endoscopic variables of IBD were found.

Conclusions

Loss of SATB2 expression is significantly associated with IBD duration, a well-known risk factor for CAC. This association with duration of IBD could denote an effect of longer chronic inflammation on SATB2 status. Given the previously reported association of loss of expression of SATB2 with pre-cancerous lesions in IBD patients, this could be a potential biomarker for risk of CAC.

Funding Agencies

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

A101 USTEKINUMAB LEVELS MEASURED DURING INDUCTION ARE ASSOCIATED WITH CLINICAL AND BIOCHEMICAL OUTCOMES AT WEEK 12 OF TREATMENT IN CROHN’S DISEASE

Background

Therapeutic drug monitoring (TDM) helps guide use of anti-TNF drugs in IBD patients. In addition, higher anti-TNF levels during induction therapy have been shown to be associated with better clinical and endoscopic outcomes. The role of TDM for more novel biologics such as ustekinumab (an anti- IL-12/23 antibody used to treat Crohn’s disease) remains to be elucidated.

Aims

We set out to investigate correlations between ustekinumab drug levels measured during induction with clinical and biochemical outcomes in patients with Crohn’s disease.

Methods

Patients with Crohn’s disease commencing treatment with ustekinumab were recruited from a single tertiary referral centre. Standard weight-based induction dosing was used. TDM was performed at week 2 and week 6 following IV induction dose. A drug-tolerant assay (Prometheus) was used. Kruskal-Wallis test was used to examine association between induction dose and ustekinumab levels. CDAI, CRP, and faecal calprotectin (FCP) were measured at week 12. Pearson correlation co-efficient was used to assess the relationship between ustekinumab levels and i)CDAI ii)CRP and iii)FCP at week 12.

Results

A total of 38 ustekinumab levels in 21 patients were measured. Week 2 ustekinumab levels were available for 17 patients, 16 (94.1%) of whom had levels of greater or equal to 25μg/mL. (1 patient had a level of 19.5μg/mL.) Week 6 ustekinumab levels were available for 21 patients; median 15μg/mL (IQR 9.9–21.3). No patients had detectable antibodies to ustekinumab. There was no significant association between absolute induction dose and week 6 ustekinumab levels; p=0.46.

Of the 21 patients with week 6 levels, CDAI, CRP and FCP were available for 18, 18 and 16 patients respectively; Median CDAI 103(IQR 42–249), median CRP 2.3mg/L(IQR 1.0–11.3), median FCP 269μg/g(IQR109-932).

There was a significant negative correlation between week 6 ustekinumab levels and CDAI; r=-.609, p=0.007. A negative correlation between week 6 ustekinumab levels and FCP was also significant; r=-.526, p=0.037. There was no significant correlation between week 6 ustekinumab levels and CRP; r=-.259, p=0.298.

Conclusions

We have demonstrated inter-patient variation in drug pharmacokinetics at week 6 following induction dose of ustekinumab in patients with Crohn’s disease. Drug levels at week 6 are significantly associated with clinical and biochemical markers of disease activity (CDAI, faecal calprotectin) at week 12. Measurement of week 6 ustekinumab levels may aid early identification of patients at risk of primary non-response to ustekinumab.

Funding Agencies

Testing provided by Prometheus

The extent of B-cell activation and dysfunction preceding lymphoma development in HIV-positive people

OBJECTIVES

B-cell dysfunction and activation are thought to contribute to lymphoma development in HIV-positive people; however, the mechanisms are not well understood. We investigated levels of several markers of B-cell dysfunction [free light chain (FLC)-κ, FLC-λ, immunoglobulin G (IgG), IgA, IgM and IgD] prior to lymphoma diagnosis in HIV-positive people.

METHODS

A nested matched case-control study was carried out within the EuroSIDA cohort, including 73 HIV-positive people with lymphoma and 143 HIV-positive lymphoma-free controls. Markers of B-cell dysfunction were measured in prospectively stored serial plasma samples collected before the diagnosis of lymphoma (or selection date in controls). Marker levels ≤ 2 and > 2 years prior to diagnosis were investigated.

RESULTS

Two-fold higher levels of FLC-κ [odds ratio (OR) 1.84; 95% confidence interval (CI) 1.19, 2.84], FLC-λ (OR 2.15; 95% CI 1.34, 3.46), IgG (OR 3.05; 95% CI 1.41, 6.59) and IgM (OR 1.46; 95% CI 1.01, 2.11) were associated with increased risk of lymphoma > 2 years prior to diagnosis, but not ≤ 2 years prior. Despite significant associations > 2 years prior to diagnosis, the predictive accuracy of each marker was poor, with FLC-λ emerging as the strongest candidate with a c-statistic of 0.67 (95% CI 0.58, 0.76).

CONCLUSIONS

FLC-κ, FLC-λ and IgG levels were higher > 2 years before lymphoma diagnosis, suggesting that B-cell dysfunction occurs many years prior to lymphoma development. However, the predictive value of each marker was low and they are unlikely candidates for risk assessment for targeted intervention.

Ileal pouch-anal anastomosis for ulcerative colitis: a Canadian institution's experience

BACKGROUND

We aimed to summarize the outcomes of ulcerative colitis (UC) patients receiving an ileal pouch-anal anastamosis (IPAA) over an 11-year period at a high-volume Canadian inflammatory bowel disease (IBD) center.

METHODS

A retrospective chart review was performed for subjects with UC who underwent IPAA between 2002 and 2013. Patient charts were reviewed for demographic data, clinical characteristics, preoperative medical treatment, and surgical outcomes. Univariate and multivariate logistic regression modeling were used to determine significant factors in postoperative outcomes.

RESULTS

Seven hundred fifty-eight were included from the IBD database. The median age at the time of surgery was 37.1 (±12.1). Mean preoperative disease duration was 8.1 years (±8.7). Three hundred sixty-nine patients (48.7 %) had systemic corticosteroids (>15 mg/day) within 30 days prior to surgery. Of these, 286 patients had high dose (>30 mg/day) corticosteroids within 7 days of their first surgery. One hundred nine (14.0 %) IPAA procedures were performed laparoscopically. Pelvic pouches were created in traditional 2 (n = 460) and 3 (n = 285) stages; the remainder (n = 13) was performed in non-traditional staged operations. Early complications, defined as occurring within the same stay in hospital, consisted of pelvic abscess (n = 135, 17.8 %), small bowel obstruction (n = 134, 17.7 %), wound infection (n = 108, 14.3 %), and deep vein thrombosis (n = 33, 4.4 %). The overall pouch leak rate was 92 (12.1 %). There was one death in our study. The median length of stay was 10.3 days (SD6.0). Late complications, defined as occurring after discharge from hospital, consisted of anal stricture (n = 55, 7.3 %), pouch fistula (n = 26, 3.4 %), and functional pouch failure (n = 7, 0.9 %).

CONCLUSIONS

IPAA has been found to be a safe and effective method of surgical management of UC patients in a high-volume IBD center.

The epidemiology of herpes zoster in patients with invasive cancer

9562

Background: Given the limited available data, the aim of this study was to estimate the incidence of Herpes Zoster (HZ) in cancer patients. Methods: In this retrospective cohort study, we used the Kaiser Permanente Northern California cancer registry to identify adult health plan members diagnosed with an invasive hematologic malignancy (HM) or solid tumor malignancy (STM) during 2001–2005. Potential episodes of HZ were ascertained from time of cancer diagnosis through 2006 from electronic databases using inpatient and outpatient diagnoses, laboratory tests, and prescriptions for antivirals. HZ diagnoses were confirmed by abstraction and clinical review of information from patients' inpatient and outpatient medical records. Incidence rates were calculated as the number of new occurrences of HZ per person-time of follow-up. Age-standardized incidence ratios (SIRs) were computed to compare HZ rates in cancer patients to reported rates in the general population (Yawn et al, 2007). Results: Among the 4,728 STM patients (mean age 66 years, range 18–102), the rate of HZ was 12/1000 person years (py) of follow-up (total 9170 py). Among the 1504 HM patients (mean age 67 years, range 18–97), the rate of HZ was 33/1000 py (total 2355 py). The SIRs and 95% confidence intervals for STM and HM were 1.7 (1.4–2.1) and 4.5 (3.5–5.6), respectively. Among patients with HM, incidence rates were highest in the first year after cancer diagnosis (40/1000 py); rates did not appear to vary markedly over time among patients with STM. For either cancer type, HZ rates were similar for males and females and did not increase consistently with increasing age. Conclusions: Compared to the general population, the incidence of HZ was nearly 2 times higher in patients with STM and over 4 times higher in patients with HM. HZ rates did not differ markedly by age or gender.

[Table: see text]

Role and extent of neck dissection for persistent nodal disease following chemo-radiotherapy for locally advanced head and neck cancer: how much is enough?

PURPOSE

Neck dissection (ND) is routinely performed for persistent nodal disease after definitive chemo-radiotherapy (CRT) for locally advanced head and neck cancer. This study analyzes the role and extent of ND necessary after CRT based on pathologic outcome.

PATIENTS AND METHODS

The study is based on 42 patients undergoing 48 ND's for persistent nodal disease after CRT. Patients were treated to a median radiation dose of 70.4 Gy at 1.8-2 Gy per fraction concurrently with platinum based chemotherapy. Patients with documented residual disease in neck, based on clinical or radiological examination underwent ND at a median interval of 59 days after completion of CRT.

RESULTS

Of the 42 patients undergoing ND, 11 (26%) had positive findings on pathologic evaluation. The clinical and treatment characteristics were similar for node negative and positive patients. The involved nodal level(s) were always confined within the clinically documented persistent disease. The median percentage of positive nodes to total nodes removed was 10%. Almost 50% of positive nodes removed had only microscopic or minute viable cancer pathologically. The outcome was better for pathologically node negative patients in comparison to node positive patients.

CONCLUSION

The results of this study suggest that standard ND appears to be an excessive treatment for persistent nodal disease after CRT. Limited ND or even gross nodal resection confined to involved nodal level(s) as identified clinically or radiologically should be tested in a prospective randomized trial for reducing treatment related morbidity while maintaining excellent loco-regional control.

The effect of pregnancy on the response to blood loss in a rat model

STUDY OBJECTIVES

A commonly held belief is that the blunted hemodynamic response to hemorrhage observed in pregnant women is secondary to expanded blood volume. In addition to increased blood volume, pregnancy is also a vasodilated state. Vasodilatation may have deleterious effects on the response to hemorrhage by inhibiting central blood shunting after blood loss. How these conflicting variables of increased blood volume and vasodilatation integrate into a whole body model of maternal hemorrhagic shock has yet to be studied in a controlled experiment. We tested the null hypothesis that there would be no difference in the hemodynamic and metabolic responses to hemorrhage between pregnant (PRG) and non-pregnant (NPRG) rats.

METHODS

Twenty-four adult female Sprague-Dawley rats (12 PRG and 12 NPRG) were anesthetized with Althesin via the intraperitoneal route. Femoral arteries were cannulated by cut-down. Twelve (six PRG and six NPRG) rats underwent controlled catheter hemorrhage of 25% of their total blood volume. Twelve rats (six PRG and six NPRG) served as non-hemorrhage controls. Mean arterial pressure (MAP) and base excess (BE) were measured pre-hemorrhage and then every 15 min post-hemorrhage for the next 90 min. Data were reported as mean+/-standard error of the mean (S.E.M.) over the 90-min post-hemorrhage observation period. Group comparisons were analyzed by ANOVA with repeated values post-hoc by Bonferroni. Statistical significance was defined by an alpha=0.05.

RESULTS

PRG and NPRG rats were evenly matched for MAP (P=0.788) and BE (P=0.146) pre-hemorrhage. Post-hemorrhage there were no mortalities in either group. Post-hemorrhage both the PRG and NPRG groups experienced significant (P=0.011) drops in systolic and diastolic blood pressures as compared to their non-hemorrhage controls. Post-hemorrhage there was no significant (P=0.43) difference in MAP between the PRG (89+/-2 mmHg) and NPRG (80+/-2 mmHg) rats. BE also dropped significantly within both PRG (P=0.004) and NPRG (P=0.001) groups post-hemorrhage. No significant (P=0.672) difference was noted in BE between PRG and NPRG groups post-hemorrhage -6.1+/-0.3 mEq/l and -6.9+/-0.4 mEq/l, respectively.

CONCLUSION

After a controlled hemorrhage of 25% of total blood volume we found no significant differences in MAP and BE between pregnant and non-pregnant rats. Pregnancy does not affect the response to hemorrhage.

Duane's syndrome with compressive denervation of the lateral rectus muscle

PURPOSE

To describe an unusual case of Duane's syndrome.

METHODS

Individual case report.

RESULTS

A skull base meningioma was discovered in a woman with Duane's syndrome who presented with recurrent, large-angle esotropia and uncharacteristic atrophy of the lateral rectus muscle on magnetic resonance image (MRI) scan.

CONCLUSION

Neuroimaging may be useful in unusual cases of Duane's syndrome.

A two-year experience teaching computer literacy to first-year medical students using skill-based cohorts

Because it is widely accepted that providing information online will play a major role in both the teaching and practice of medicine in the near future, a short formal course of instruction in computer skills was proposed for the incoming class of students entering medical school at the State University of New York at Stony Brook. The syllabus was developed on the basis of a set of expected outcomes, which was accepted by the dean of medicine and the curriculum committee for classes beginning in the fall of 1997. Prior to their arrival, students were asked to complete a self-assessment survey designed to elucidate their initial skill base; the returned surveys showed students to have computer skills ranging from complete novice to that of a systems engineer. The classes were taught during the first three weeks of the semester to groups of students separated on the basis of their knowledge of and comfort with computers. Areas covered included computer basics, e-mail management, MEDLINE, and Internet search tools. Each student received seven hours of hands-on training followed by a test. The syllabus and emphasis of the classes were tailored to the initial skill base but the final test was given at the same level to all students. Student participation, test scores, and course evaluations indicated that this noncredit program was successful in achieving an acceptable level of comfort in using a computer for almost all of the student body.

Decompensated strabismus after laser in situ keratomileusis

We present a case of decompensated nerve IV palsy with vertical diplopia afer bilateral laser in situ keratomileusis. As the patient was given monovision, we believe diplopia occurred with a decrease in vision in 1 eye and interruption of fusion. Although corrective spectacles to restore equal vision at distance were prescribes, the patient needed a prism to eliminate her double vision. We suggest a careful cover/uncover test and versions assessment in all candidates for refractive surgery who want monovision correction and a full ocular motility evaluation if there is any doubt about binocular issues.

Nonsurgical management of binocular diplopia induced by macular pathology

OBJECTIVE

To treat binocular diplopia secondary to macular pathology.

METHODS

Seven patients underwent evaluation and treatment. All had constant vertical diplopia caused by various maculopathies, including subretinal neovascularization, epiretinal membrane, and central serous retinopathy. Visual acuity ranged from 20/20 to 20/30 in the affected eye. All except 1 patient had a small-angle, comitant hyperdeviation with no muscle paresis. Sensory evaluation demonstrated peripheral fusion and reduced stereoacuity. Neither prism correction nor manipulation of the refractive errors corrected the diplopia. A partially occlusive foil (Bangerter) of density ranging from 0.4 to 1.0 was placed in front of the affected eye to restore stable, single vision.

RESULTS

The Bangerter foil eliminated the diplopia in all patients. Two patients elected not to wear the foil; 1 patient was afraid of becoming dependent, and the other was bothered by the visual blur. Visual acuity in the affected eye was reduced on average by 3 lines. All patients maintained the same level of sensory fusion, with only 2 having reduced stereoacuity. Symptoms returned when the foil was removed or its density was reduced.

CONCLUSION

Low-density Bangerter foils provide an effective, inexpensive, and aesthetically acceptable management for refractory binocular diplopia induced by macular pathology, allowing peripheral fusion to be maintained.

Absence of linkage between inflammatory bowel disease and selected loci on chromosomes 3, 7, 12, and 16

BACKGROUND & AIMS

Linkage data derived from genome-wide scans of inflammatory bowel disease (IBD) sibling-pair families have identified 4 loci on chromosomes 3, 7, 12, and 16 as potential sites for IBD susceptibility genes. The aim of this study was to investigate whether linkage analysis of another independently collected set of sibling pairs with IBD would provide further evidence of linkage between these previously reported loci and IBD.

METHODS

Using the MAPMAKER/SIBS program, the segregation of 21 microsatellite marker loci spanning the 4 putative IBD gene loci was analyzed in a study population comprising 161 families with 114 Crohn's disease, 36 ulcerative colitis, and 50 mixed IBD sibling pairs from the Greater Toronto area.

RESULTS

The results of multipoint linkage analysis showed no evidence for linkage between IBD and each of the 21 marker loci studied; the logarithm of odds scores in all instances were less than 0.8. These linkage data were found, by exclusion mapping analysis, to exclude values of lambdas ranging from 1.5 to 3.0, depending on the locus evaluated.

CONCLUSIONS

The loci previously suggested as representing IBD susceptibility loci are not linked to IBD in the Toronto population examined in this analysis.

Early diagnosis of mycotic keratitis: predictive value of potassium hydroxide preparation

Potassium hydroxide (KOH) preparation is an underutilized modality in the diagnosis of mycotic keratitis. We have earlier shown its utility in the diagnosis of Nocardia and Acanthamoeba keratitis. The aim of this study was (i) to evaluate the sensitivity, specificity and predictive value of KOH preparation, and (ii) to compare its efficacy with other methods of corneal scraping examination, for the diagnosis of mycotic keratitis. The study was conducted in two phases. In phase I, randomized corneal scrapings were examined by KOH, Gram's stain, and lactophenol cotton blue (LPCB) in 91 infectious keratitis subjects. In phase II, 53 corneal scrapings were stained with KOH and calcofluor white (CFW), and viewed with bright field (KOH) and fluorescence (CFW) microscopy. The KOH and CFW readings were recorded by an observer masked to the clinical findings and culture results. Nineteen scrapings were examined by two masked observers. In 22 culture positive fungal keratitis patients in phase I, the sensitivity of KOH, Gram's stain, and LPCB methods was 100%, 86.4%, and 77.3%, respectively. In phase II, the specificities of KOH and CFW were identical (83.8%), while the sensitivities were 81.2% and 93.7%, respectively (p = 0.59), in 16 culture positive mycotic keratitis patients. There was no significant difference between the negative and positive predictive values of KOH and CFW. Furthermore, no significant interobserver variability was found in the specificity and sensitivity. The KOH method compares well with other microscopy methods in the diagnosis of keratomycosis and has a definite place in the armamentarium of diagnostic techniques.

Mast cell derived heparin activates the contact system: a link to kinin generation in allergic reactions

Contact activation occurs when plasma comes in contact with negatively charged manmade surfaces but no substance that initiates contact activation in vivo has been identified. We have isolated a mast cell heparin proteoglycan (MC-HepPG) from a Furth mouse mastocytoma-derived cell line that is analogous to human tissue-type mast cell HepPG. This material and other glycosaminoglycans (GAGs) were tested for their ability to accelerate the reciprocal activation of factor XII and prekallikrein and the autoactivation of factor XII. Quantitative analysis showed the MC-HepPG to be as active as dextran sulfate on a weight basis; hog intestine heparin, dermatan sulfate, keratan polysulfate and chondroitin sulfate C were less active, other sulfated polysaccharides were essentially inactive. Incubation of MC-HepPG in 1:4 diluted plasma resulted in complete cleavage of high molecular weight kininogen in a factor XII-dependent reaction. All of the MC-HepPG dependent reactions described above were inhibited by preincubation of MC-HepPG with heparinase I and II but not by pretreatment with heparitinase, chondroitinase ABC or the serine protease inhibitor aPMSF thus indicating that heparin proteoglycan is indeed acting as an initiating 'surface'. We analysed the proteoglycan preparation by HPLC gel filtration. Fractions spanning a molecular weight range of > 400000-8000 were active initiators. Comparison of the chromatograms obtained before and after cleavage of GAG side chains from the protein core suggested that dissociated GAGs in the MW range 69000-17000 are the most active species rather than the complete proteoglycan. MC-HepPG GAGs therefore represent a physiologic macromolecule with activity comparable to non-physiological surfaces in a purified system and with the capability to induce activation of the contact system in diluted plasma. Its ability to promote kinin generation links cellular and humoral inflammatory responses in the perivasculature and provides a possible explanation for the elevated kinin levels observed after allergen exposure.

ATP modification of serotonin-induced contraction of the rat pulmonary artery

Serotonin (5HT) and ATP are simultaneously released from activated platelets at the site of vascular injury and are hypothesized to play a significant role in hemostasis. Our laboratory investigated the modulation of vascular contraction of arterial ring segments by 5HT plus ATP as a model of the potential regulation of localized vascular tone by platelet releasates in regions of arterial damage. This study expands our focus on how these two vasoactive components, released from platelet dense granules, regulate vascular tone. 5HT- and 5HT analog-induced vasoconstrictions were measured in the presence or absence of ATP and ATP analogs with intact or deendothelialized rat pulmonary arterial ring segments suspended in organ baths. The possible presence of 5HT2 and 5HT1A receptor types in the rat pulmonary artery was demonstrated by vasoconstrictions induced by 5HT and (+)-8-hydroxy-2-(di-N-propylamino) tetralin hydrobromide (DPAT). The DPAT response was only 30%-50% of that induced by comparable concentrations of 5HT. The 5HT-induced contraction was inhibited by the 5HT2 antagonist, ketanserin. ATP equally relaxed 5HT and DPAT contracted tissue while the P2X agonist, alphabeta-methylene ATP, increased the contracted state of DPAT-treated arteries to a significantly greater extent than observed with 5HT. The P2y agonist, 3'-O-(4-benzoyl)benzoyl ATP (BzATP), the P2X agonist betagamma-methylene ATP, and ATP all relaxed 5HT-induced contractions to similar levels under a number of physiological conditions. The final level of 5HT-induced tissue contraction was the same whether ATP was added prior to, after, or simultaneously with 5HT. ATP and the phosphodiesterase inhibitor, theophylline, inhibited 5HT-induced vasoconstriction in an additive fashion. The ATP effects were endothelium dependent, while the inhibition by theophylline was not. The distribution of 5HT and ATP receptor types, as indicated by these and numerous other studies, appears to vary within different regions of the cardiovascular system. Extracellular ATP can synergistically enhance or inhibit 5HT-contracted blood vessels differentially at localized regions, which would significantly impact on localized vascular tone, and this in turn may modulate hemostasis and thrombosis.

Glomerular mesangial cell altered contractility in high glucose is Ca2+ independent

In diabetes, loss of renal arteriolar smooth-muscle cell contractility leads to intraglomerular hypertension. In glomeruli isolated from streptozotocin (STZ)-induced diabetic rats, the mesangial cells (smooth muscle-like) display loss of contractile responsiveness to angiotensin II. This study examines the mechanistic relationship between altered mesangial cell contractility and vasopressor hormone-stimulated Ca2+ signaling in high glucose. Glomeruli were isolated from normal or STZ-induced diabetic rats to observe ex vivo mesangial cell contractile function. Also, rat mesangial cells were cultured (10-20 passages) in normal (5.6 mmol/l) or high (10-25.6 mmol/l) glucose for 1-5 days. Reduction of glomerular volume and decreased planar surface area of cultured mesangial cells in response to vasoconstrictor stimulation over 60 min were measured by videomicroscopy and personal computer-based morphometry. Contraction of glomeruli isolated from STZ-administered rat in response to endothelin (ET)-1 (0.1 mumol/l) or the Ca2+ ionophore A23187 (5 mumol/l) was impaired significantly compared with that in normal glucose. In the presence of arginine vasopressin (AVP) (1.0 mumol/l) or ET-1 (0.1 mumol/l), mesangial cells demonstrated a dose-dependent loss of contractile response to increasing glucose concentrations (5.6-25.6 mmol/l) within 24 h of high-glucose exposure, which was sustained for 5 days. Mesangial cells in high glucose were consistently smaller in size compared with those in normal glucose. Mesangial cells were preloaded with myo-[2-3H]inositol and intracellular [3H] inositol phosphate release in response to AVP (1.0 mumol/l) was analyzed by Dowex chromatography. Comparing cells in normal (5.6 mmol/l) verus high (25.6 mmol/l) glucose, we observed no significant difference in stimulated inositol phosphate levels from 10 to 60 s.(ABSTRACT TRUNCATED AT 250 WORDS)

Assembly of the human plasma kinin-forming cascade along the surface of vascular endothelial cells

The generation of bradykinin by contact activation requires autoactivation of factor XII (Hageman factor) upon initiating surfaces, conversion of prekallikrein to kallikrein, and digestion of high-molecular-weight (HMW) kininogen. Endothelial cells have a high-affinity receptor that binds either HMW kininogen or factor XII in a zinc-dependent interaction, and activation of factor XII can occur along this surface to initiate kinin formation. Tissue injury, exposure of proteoglycans, or release of mast cell heparin will markedly accelerate these reactions. The bradykinin released binds to endothelial cell B-2 receptors along the inner surface of blood vessels which results in dilatation and increased vascular permeability.

Clinical utility and validation of emerging biochemical markers for mammary adenocarcinoma

The clinical utilities of the emerging biochemical markers for mammary adenocarcinoma CA 15-3, CA 549, CA M26, CA M29, and MCA (mucin-like carcinoma-associated antigen) were assessed by a formal rating according to six desirable marker characteristics. All five indicators similarly have good specificities but limited sensitivities. As a consequence, these markers mainly meet just two desirable criteria: their frequency and degree of expression reflect tumor burden and prognosis, and they may correlate with therapeutic results. The validation of these assay properties by clinical trials was evaluated by another rating system, designed to assess proband sample selection, restrictions on allowable observations, and choice of statistical descriptors. By these benchmarks, the estimates of the prior probabilities of test outcome (sensitivity and specificity) are reasonably definitive, but conclusive judgments about the posterior probabilities of test outcome ("predictive values") and about values and costs associated with testing are not possible. Three approaches to enhance the limited clinical utility of biochemical breast cancer markers are considered: shifts of the diagnostic decision threshold, marker panels, and sequential testing. However, none of these strategies improves the described performance characteristics.

Clinical utility and validation of emerging biochemical markers for mammary adenocarcinoma

The clinical utilities of the emerging biochemical markers for mammary adenocarcinoma CA 15-3, CA 549, CA M26, CA M29, and MCA (mucin-like carcinoma-associated antigen) were assessed by a formal rating according to six desirable marker characteristics. All five indicators similarly have good specificities but limited sensitivities. As a consequence, these markers mainly meet just two desirable criteria: their frequency and degree of expression reflect tumor burden and prognosis, and they may correlate with therapeutic results. The validation of these assay properties by clinical trials was evaluated by another rating system, designed to assess proband sample selection, restrictions on allowable observations, and choice of statistical descriptors. By these benchmarks, the estimates of the prior probabilities of test outcome (sensitivity and specificity) are reasonably definitive, but conclusive judgments about the posterior probabilities of test outcome ("predictive values") and about values and costs associated with testing are not possible. Three approaches to enhance the limited clinical utility of biochemical breast cancer markers are considered: shifts of the diagnostic decision threshold, marker panels, and sequential testing. However, none of these strategies improves the described performance characteristics.

Bradykinin generation by dialysis membranes: possible role in anaphylactic reaction

Several recent reports have described a high incidence of anaphylactic reactions in patients being dialyzed with high-flux membranes while simultaneously using angiotensin-converting enzyme inhibitors. Many of these reports implicate polyacrylonitrile (PAN) as the membrane commonly involved in these reactions. To elucidate potential mechanisms of these anaphylactic reactions, whether dialysis membranes can activate the Hageman factor-dependent (contact) pathways as assessed by the in vitro generation of activated Hageman factor (Hfa), as well as the formation of kallikrein and subsequent bradykinin generation was examined. Both cuprophane (CUP) and PAN membranes were able to activate Hageman factor and convert prekallikrein to kallikrein as measured by an ELISA against kallikrein-C1-inactivator complexes. Subsequently, the active kallikrein was able to cleave bradykinin from its endogenous substrate, high-molecular-weight kininogen. However, it was found that the PAN membrane consistently led to an earlier and significantly higher formation of Hfa and kallikrein when compared with CUP. Importantly, there was also a pronounced but transient generation of bradykinin by the PAN membrane, in contrast to slower bradykinin formation by CUP, with both normal and uremic blood. It was proposed that the early and vigorous bradykinin generation induced by the contact of blood with PAN could explain, in part, the pathogenesis of the reported anaphylactoid reactions.

Activation of factor XI in plasma is dependent on factor XII

The activation of factor XI initiates the intrinsic coagulation pathway. Until recently it was believed that the main activator of factor XI is factor XIIa in conjunction with the cofactor high molecular weight kininogen on a negatively charged surface. Two recent reports have presented evidence that in a purified system factor XI is activatable by thrombin together with the soluble polyanion dextran sulfate. To assess the physiological relevance of these findings we studied the activation of factor XI in normal and factor XII-deficient plasma. We used either kaolin/cephalin or dextran sulfate as a surface for the intrinsic coagulation pathway, tissue factor to generate thrombin via the extrinsic pathway, or the addition of alpha-thrombin directly. 125I-factor XI, added to factor XI-deficient plasma at physiologic concentrations (35 nmol/L), is rapidly cleaved on incubation with kaolin. The kinetics appear to be exponential with half the maximum cleavage at 5 minutes. Similar kinetics of factor XI cleavage are seen when 40 nmol/L factor XIIa (equal to 10% of factor XII activation) is added to factor XII-deficient plasma if an activating surface is provided. Tissue factor (1:500) added to plasma did not induce cleavage of factor XI during a 90-minute incubation, although fibrin formation within 30 seconds indicated that thrombin was generated via the extrinsic pathway. Adding 1 mumol/L alpha-thrombin (equivalent to 50% prothrombin activation) directly to factor XII deficient or normal plasma (with or without kaolin/cephalin/Ca2+ or dextran sulfate) led to instantaneous fibrinogen cleavage, but again no cleavage of factor XI was observable. We conclude that in plasma surroundings factor XI is not activated by thrombin, and that proposals of thrombin initiation of the intrinsic coagulation cascade are not supportable.

Effect of Neurotropin on the activation of the plasma kallikrein-kinin system

Bradykinin (BK), an important mediator of allergic reactions and pain induction, is released by the activation of the plasma kallikrein-kinin (K-K) cascade. Neurotropin is a biological material obtained from inflamed rabbit skin inoculated with vaccinia virus and is widely used clinically in Japan as an effective agent for these disorders. Since its mechanism of action is not clearly known, we have investigated the effects of Neurotropin on the human plasma K-K system. In dextran sulfate-activated plasma, Neurotropin inhibited the formation of BK, the cleavage of high molecular weight kininogen (HK) and the formation of kallikrein-C1 inhibitor and activated coagulation factor XII (FXIIa)-C1 inhibitor complexes. Experiments using purified enzyme of the K-K cascade indicated that Neurotropin inhibited surface-mediated activation of coagulation factor XII (FXII) and the activation of prekallikrein by FXIIa. Neurotropin also inhibited the binding of FXII and HK to the activating surface. These data suggest that the ameliorating effects of Neurotropin in allergic disorders and pain syndromes may be related to this ability to inhibit activation of the K-K cascade and consequently the formation of BK.

Continuous infusion gallium nitrate for patients with advanced refractory urothelial tract tumors

A Phase I-II trial of gallium nitrate was conducted in 40 patients with bidimensionally measurable urothelial tract tumors who had failed to respond to combination chemotherapy with methotrexate, vinblastine, doxorubicin, and cisplatin. Partial responses were observed in 4 of 23 patients (17.4%) who received 350 mg/m2/d or more for 5 days by continuous intravenous infusion. In two additional patients who received 350 mg/m2/d or more, a minor response and a mixed response were observed. The median duration of response was 4 months (range, 2 to 8 months). A dose-response relationship was suggested because no responses were observed in 17 patients who received less than 350 mg/m2/d. Myelosuppression was minimal. The dose-limiting toxic reaction was a reversible optic neuropathy that occurred in 3 of 11 patients who received 400 mg/m2/d. Further evaluation of infusional gallium nitrate is warranted in patients with urothelial tract malignant tumors.

Chronic abdominal pain in adolescents

Although there are very few prospective studies of CAP, organic causes of the problem are misdiagnosed probably in less than 5% of adolescents. Response to treatment seems to be better in males who have had signs and symptoms for less than 6 months, and is rather poor for patients with complaints exceeding 2 years. An organized nomenclature is necessary for classifying dysfunctional disorders, and physicians must recognize that these patients represent a heterogeneous population. In general, adequate data for the number of the adolescent population affected by these diseases is not available, so that physicians are still required to depend to a large extent on speculation and anecdotal information in assessing and managing these patients.

Clinical pharmacology of the neuromuscular blocking agents

Neuromuscular blocking agents are among the most commonly used drugs during general anesthesia. They compete with acetylcholine and interfere with the transmission of nerve impulses resulting in skeletal muscle relaxation. Based on their mechanism of action, neuromuscular blocking agents are classified as either depolarizing or nondepolarizing. Succinylcholine is a short-acting depolarizing agent. Commonly used nondepolarizing agents are curare (long-acting), pancuronium (long-acting), atracurium (intermediate-acting), and vecuronium (intermediate-acting). Neuromuscular blocking agents are used clinically to facilitate endotracheal intubation and to provide skeletal muscle relaxation during surgery. This article provides an overview of the physiology of the neuromuscular transmission and summarizes our current knowledge on the use of these agents during general anesthesia.

Cutaneous photosensitivity and coproporphyrin abnormalities in the Alagille syndrome

Porphyria cutanea tarda-like blistering, fragility, and scarring of light-exposed skin was observed in four children with the Alagille syndrome. Abnormally elevated levels of serum porphyrins, of which coproporphyrin isomers I and III together accounted for 50%-89% of the total, were found in these four children but also in three other children with the Alagille syndrome without such skin lesions. The ratio for isomer I to III for total serum coproporphyrin concentration was determined in six cases; the concentration of isomer I was greater than or equal to that of isomer III in each case. Urinary total porphyrin excretion was found to be elevated in six of the seven cases, with 72% +/- 8% occurring as coproporphyrins I and III. The ratio for urinary coproporphyrin I to III was greater than or equal to 1 in six of these patients, the reverse of the typical normal isomer distribution. Inasmuch as the presence or absence of photocutaneous lesions did not correlate with levels of porphyrins in serum or urine, other factors may be involved in the pathogenesis of the skin lesions.

Pathways of kinin formation and role in allergic diseases

We have developed new assays for the assessment of the plasma kinin forming system which have increased sensitivity and specificity. We utilize double-antibody ELISA assays for quantitation of complexes of activated Hageman factor-C1 inhibitor, kallikrein-C1 inhibitor, and kallikrein-alpha 2-macroglobulin which reflect activation of each enzyme. The fraction of cleaved high-molecular-weight kininogen is determined by immunoblotting using a monoclonal antibody to the light chain, and bradykinin is determined by radioimmunoassay. Activation of the Hageman factor-dependent pathway of kinin formation can occur when plasma is in contact with initiating surfaces or when C1 inhibitor function is diminished. The latter mechanism can occur in hereditary angioedema, in which the protein is absent or dysfunctional, or when plasma is diluted so that the effect of inhibitors is diminished and Hageman factor autoactivation is facilitated. Thus apparent "spontaneous" generation of bradykinin is seen upon incubation of plasma of hereditary angioedema patients under conditions in which normal plasma is unaffected. Studies of late-phase reactions have used a cutaneous model in which induced blisters are unroofed and challenged with antigen or buffer control using chambers which can be changed hourly. A time course of mediator release is obtained by assay of the blister fluids. Whereas most histamine is released during the first half hour, significantly elevated levels of activated Hageman factor and kallikrein complexes with C1 inactivator are seen in antigen-challenged sites between 4 and 6 hr. The presence of such complexes correlated with the presence of late-phase reactions rather than the histamine values or the magnitude of the immediate reaction. Although late-phase reactions are characterized by cellular infiltration, release of a variety of inflammatory low-molecular-weight mediators, and deposition of fibrin, activation of the Hageman factor-dependent pathway of kinin formation is also likely to be contributory.

The autoactivation of factor XII (Hageman factor) induced by low-Mr heparin and dextran sulphate. The effect of the Mr of the activating polyanion

Human Factor XII is known to undergo autoactivation in the presence of dextran sulphate of Mr 500,000. We have now studied the dependence of this reaction on the Mr of the dextran sulphate by using fractions resolved by gel filtration. We have found that autoactivation can be induced by dextran sulphate fractions with Mr as low as 3000, and there is a marked dependence of the rate constant of autoactivation on the Mr value. Fractions with Mr below 8000 gave very low rates of autoactivation; there was a sharp increase in the rate obtained when the Mr of the dextran sulphate was greater than 10,000. Various preparations of heparin were also able to support the autoactivation of Factor XII and gave a very similar relationship between molecular size and reaction rate. The data provide support for the hypothesis that the mechanism by which the 'surface' acts in contact activation involves the presence, on the same particle, of multiple binding sites for the proteins.