Implications for sequencing of biologic therapy and choice of second anti-TNF in patients with inflammatory bowel disease: results from the IMmunogenicity to Second Anti-TNF therapy (IMSAT) therapeutic drug monitoring study

BACKGROUND

Anti-drug antibodies are associated with treatment failure to anti-TNF agents in patients with inflammatory bowel disease (IBD).

AIM

To assess whether immunogenicity to a patient's first anti-TNF agent would be associated with immunogenicity to the second, irrespective of drug sequence METHODS: We conducted a UK-wide, multicentre, retrospective cohort study to report rates of immunogenicity and treatment failure of second anti-TNF therapies in 1058 patients with IBD who underwent therapeutic drug monitoring for both infliximab and adalimumab. The primary outcome was immunogenicity to the second anti-TNF agent, defined at any timepoint as an anti-TNF antibody concentration ≥9 AU/ml for infliximab and ≥6 AU/ml for adalimumab.

RESULTS

In patients treated with infliximab and then adalimumab, those who developed antibodies to infliximab were more likely to develop antibodies to adalimumab, than patients who did not develop antibodies to infliximab (OR 1.99, 95%CI 1.27-3.20, p = 0.002). Similarly, in patients treated with adalimumab and then infliximab, immunogenicity to adalimumab was associated with subsequent immunogenicity to infliximab (OR 2.63, 95%CI 1.46-4.80, p < 0.001). For each 10-fold increase in anti-infliximab and anti-adalimumab antibody concentration, the odds of subsequently developing antibodies to adalimumab and infliximab increased by 1.73 (95% CI 1.38-2.17, p < 0.001) and 1.99 (95%CI 1.34-2.99, p < 0.001), respectively. Patients who developed immunogenicity with undetectable drug levels to infliximab were more likely to develop immunogenicity with undetectable drug levels to adalimumab (OR 2.37, 95% CI 1.39-4.19, p < 0.001). Commencing an immunomodulator at the time of switching to the second anti-TNF was associated with improved drug persistence in patients with immunogenic, but not pharmacodynamic failure.

CONCLUSION

Irrespective of drug sequence, immunogenicity to the first anti-TNF agent was associated with immunogenicity to the second, which was mitigated by the introduction of an immunomodulator in patients with immunogenic, but not pharmacodynamic treatment failure.

Antibody decay, T cell immunity and breakthrough infections following two SARS-CoV-2 vaccine doses in inflammatory bowel disease patients treated with infliximab and vedolizumab

Anti tumour necrosis factor (anti-TNF) drugs increase the risk of serious respiratory infection and impair protective immunity following pneumococcal and influenza vaccination. Here we report SARS-CoV-2 vaccine-induced immune responses and breakthrough infections in patients with inflammatory bowel disease, who are treated either with the anti-TNF antibody, infliximab, or with vedolizumab targeting a gut-specific anti-integrin that does not impair systemic immunity. Geometric mean [SD] anti-S RBD antibody concentrations are lower and half-lives shorter in patients treated with infliximab than vedolizumab, following two doses of BNT162b2 (566.7 U/mL [6.2] vs 4555.3 U/mL [5.4], p <0.0001; 26.8 days [95% CI 26.2 - 27.5] vs 47.6 days [45.5 - 49.8], p <0.0001); similar results are also observed with ChAdOx1 nCoV-19 vaccination (184.7 U/mL [5.0] vs 784.0 U/mL [3.5], p <0.0001; 35.9 days [34.9 - 36.8] vs 58.0 days [55.0 - 61.3], p value < 0.0001). One fifth of patients fail to mount a T cell response in both treatment groups. Breakthrough SARS-CoV-2 infections are more frequent (5.8% (201/3441) vs 3.9% (66/1682), p = 0.0039) in patients treated with infliximab than vedolizumab, and the risk of breakthrough SARS-CoV-2 infection is predicted by peak anti-S RBD antibody concentration after two vaccine doses. Irrespective of the treatments, higher, more sustained antibody levels are observed in patients with a history of SARS-CoV-2 infection prior to vaccination. Our results thus suggest that adapted vaccination schedules may be required to induce immunity in at-risk, anti-TNF-treated patients.

Adalimumab and Infliximab Impair SARS-CoV-2 Antibody Responses: Results from a Therapeutic Drug Monitoring Study in 11 422 Biologic-Treated Patients

BACKGROUND AND AIMS

Infliximab attenuates serological responses to SARS-CoV-2 infection. Whether this is a class effect, or if anti-tumour necrosis factor [anti-TNF] level influences serological responses, remains unknown.

METHODS

Seroprevalence and the magnitude of SARS-CoV-2 nucleocapsid antibody responses were measured in surplus serum from 11 422 (53.3% [6084] male; median age 36.8 years) patients with immune-mediated inflammatory diseases, stored at six therapeutic drug monitoring laboratories between January 29 and September 30, 2020. Data were linked to nationally held SARS-CoV-2 PCR results to July 11, 2021.

RESULTS

Rates of PCR-confirmed SARS-CoV-2 infection were similar across treatment groups. Seroprevalence rates were lower in infliximab- and adalimumab- than vedolizumab-treated patients (infliximab: 3.0% [178/5893], adalimumab: 3.0% [152/5074], vedolizumab: 6.7% [25/375], p = 0.003). The magnitude of SARS-CoV-2 reactivity was similar in infliximab- vs adalimumab-treated patients (median 4.30 cut-off index [COI] [1.94-9.96] vs 5.02 [2.18-18.70], p = 0.164), but higher in vedolizumab-treated patients (median 21.60 COI [4.39-68.10, p < 0.004). Compared to patients with detectable infliximab and adalimumab drug levels, patients with undetectable drug levels [<0.8 mg/L] were more likely to be seropositive for SARS-CoV-2 antibodies. One-third of patients who had PCR testing prior to antibody testing failed to seroconvert, all were treated with anti-TNF. Subsequent positive PCR-confirmed SARS-CoV-2 was seen in 7.9% [12/152] of patients after a median time of 183.5 days [129.8-235.3], without differences between drugs.

CONCLUSION

Anti-TNF treatment is associated with lower SARS-CoV-2 nucleocapsid seroprevalence and antibody reactivity when compared to vedolizumab-treated patients. Higher seropositivity rates in patients with undetectable anti-TNF levels support a causal relationship, although confounding factors, such as combination therapy with a immunomodulator, may have influenced the results.

Patient-led Remote IntraCapillary pharmacoKinetic Sampling (fingerPRICKS) for Therapeutic Drug Monitoring in patients with Inflammatory Bowel Disease

BACKGROUND AND AIMS

Because of COVID-19 public health restrictions, telemedicine has replaced conventional outpatient follow up for most patients with chronic immune-mediated inflammatory disorders treated with biologic drugs. Innovative solutions to facilitate remote therapeutic drug monitoring are therefore required. Low-volume intracapillary blood sampling can be undertaken by patients at home and samples returned by post to central laboratories. We sought to report the effect of the COVID-19 pandemic on requests for therapeutic drug monitoring and the equivalence, acceptability and effectiveness of low volume Patient-led Remote IntraCapillary pharmacoKinetic Sampling [fingerPRICKS] compared to conventional venepuncture.

METHODS

We undertook a cross-sectional blood sampling methods comparison study and compared sample types using linear regression models. Drug and antidrug antibody levels were measured using standard ELISAs. Acceptability was assessed using a purpose-designed questionnaire.

RESULTS

Therapeutic drug monitoring requests for adalimumab (96.5 [70.5-106] per week to 52 [33.5-57.0], p < 0.001) but not infliximab (184.5 [161.2-214.2] to 161 [135-197.5], p = 0.34) reduced during the first UK stay-at-home lockdown compared with the preceding 6 months. Fingerprick sampling was equivalent to conventional venepuncture for adalimumab, infliximab, vedolizumab and ustekinumab drug, and anti-adalimumab and anti-infliximab antibody levels. The median [interquartile range] volume of serum obtained using intracapillary sampling was 195 µL [130-210]. More than 87% [90/103] of patients agreed that intracapillary testing was easy and 69% [71/103] preferred it to conventional venepuncture. In routine care, 75.3% [58/77] of patients returned two blood samples within 14 days to permit remote assessment of biologic therapeutic drug monitoring.

CONCLUSIONS

Therapeutic drug monitoring can be undertaken using patient-led remote intracapillary blood sampling and has the potential to be a key adjunct to telemedicine in patients with immune-mediated inflammatory diseases.

Infliximab is associated with attenuated immunogenicity to BNT162b2 and ChAdOx1 nCoV-19 SARS-CoV-2 vaccines in patients with IBD

OBJECTIVE

Delayed second dose SARS-CoV-2 vaccination trades maximal effectiveness for a lower level of immunity across more of the population. We investigated whether patients with inflammatory bowel disease treated with infliximab have attenuated serological responses to a single dose of a SARS-CoV-2 vaccine.

DESIGN

Antibody responses and seroconversion rates in infliximab-treated patients (n=865) were compared with a cohort treated with vedolizumab (n=428), a gut-selective anti-integrin α4β7 monoclonal antibody. Our primary outcome was anti-SARS-CoV-2 spike (S) antibody concentrations, measured using the Elecsys anti-SARS-CoV-2 spike (S) antibody assay 3-10 weeks after vaccination, in patients without evidence of prior infection. Secondary outcomes were seroconversion rates (defined by a cut-off of 15 U/mL), and antibody responses following past infection or a second dose of the BNT162b2 vaccine.

RESULTS

Geometric mean (SD) anti-SARS-CoV-2 antibody concentrations were lower in patients treated with infliximab than vedolizumab, following BNT162b2 (6.0 U/mL (5.9) vs 28.8 U/mL (5.4) p<0.0001) and ChAdOx1 nCoV-19 (4.7 U/mL (4.9)) vs 13.8 U/mL (5.9) p<0.0001) vaccines. In our multivariable models, antibody concentrations were lower in infliximab-treated compared with vedolizumab-treated patients who received the BNT162b2 (fold change (FC) 0.29 (95% CI 0.21 to 0.40), p<0.0001) and ChAdOx1 nCoV-19 (FC 0.39 (95% CI 0.30 to 0.51), p<0.0001) vaccines. In both models, age ≥60 years, immunomodulator use, Crohn's disease and smoking were associated with lower, while non-white ethnicity was associated with higher, anti-SARS-CoV-2 antibody concentrations. Seroconversion rates after a single dose of either vaccine were higher in patients with prior SARS-CoV-2 infection and after two doses of BNT162b2 vaccine.

CONCLUSION

Infliximab is associated with attenuated immunogenicity to a single dose of the BNT162b2 and ChAdOx1 nCoV-19 SARS-CoV-2 vaccines. Vaccination after SARS-CoV-2 infection, or a second dose of vaccine, led to seroconversion in most patients. Delayed second dosing should be avoided in patients treated with infliximab.

TRIAL REGISTRATION NUMBER

ISRCTN45176516.

Anti-SARS-CoV-2 antibody responses are attenuated in patients with IBD treated with infliximab

OBJECTIVE

Antitumour necrosis factor (anti-TNF) drugs impair protective immunity following pneumococcal, influenza and viral hepatitis vaccination and increase the risk of serious respiratory infections. We sought to determine whether infliximab-treated patients with IBD have attenuated serological responses to SARS-CoV-2 infections.

DESIGN

Antibody responses in participants treated with infliximab were compared with a reference cohort treated with vedolizumab, a gut-selective anti-integrin α4β7 monoclonal antibody that is not associated with impaired vaccine responses or increased susceptibility to systemic infections. 6935 patients were recruited from 92 UK hospitals between 22 September and 23 December 2020.

RESULTS

Rates of symptomatic and proven SARS-CoV-2 infection were similar between groups. Seroprevalence was lower in infliximab-treated than vedolizumab-treated patients (3.4% (161/4685) vs 6.0% (134/2250), p<0.0001). Multivariable logistic regression analyses confirmed that infliximab (vs vedolizumab; OR 0.66 (95% CI 0.51 to 0.87), p=0.0027) and immunomodulator use (OR 0.70 (95% CI 0.53 to 0.92), p=0.012) were independently associated with lower seropositivity. In patients with confirmed SARS-CoV-2 infection, seroconversion was observed in fewer infliximab-treated than vedolizumab-treated patients (48% (39/81) vs 83% (30/36), p=0.00044) and the magnitude of anti-SARS-CoV-2 reactivity was lower (median 0.8 cut-off index (0.2-5.6) vs 37.0 (15.2-76.1), p<0.0001).

CONCLUSIONS

Infliximab is associated with attenuated serological responses to SARS-CoV-2 that were further blunted by immunomodulators used as concomitant therapy. Impaired serological responses to SARS-CoV-2 infection might have important implications for global public health policy and individual anti-TNF-treated patients. Serological testing and virus surveillance should be considered to detect suboptimal vaccine responses, persistent infection and viral evolution to inform public health policy.

TRIAL REGISTRATION NUMBER

ISRCTN45176516.

Root-cause analyses of missed opportunities for the diagnosis of colorectal cancer in patients with inflammatory bowel disease

BACKGROUND

Colonoscopic surveillance in patients with inflammatory bowel disease (IBD) leads to earlier detection of colorectal cancer (CRC) and reduces CRC-associated mortality. However, it is limited by poor adherence in practice.

AIM

To identify missed opportunities to detect IBD-associated CRC at our hospital METHODS: We undertook root-cause analyses to identify patients with missed opportunities to diagnose IBD-associated CRC. We matched patients with IBD-associated CRC to patients with CRC in the general population to identify differences in staging at diagnosis and clinical outcomes.

RESULTS

Compared with the general population, patients with IBD were at increased risk of developing CRC (odds ratio 2.7 [95% CI 1.6-3.9], P < 0.001). The mean incidence of IBD-associated CRC between 1998 and 2019 was 165.4 (IQR 130.4-199.4) per 100 000 patients and has not changed over the last 20 years. Seventy-eight patients had IBD-associated CRC. Forty-two (54%) patients were eligible for CRC surveillance: 12% (5/42) and 10% (4/42) patients were diagnosed with CRC at an appropriately timed or overdue surveillance colonoscopy, respectively. Interval cancers occurred in 14% (6/42) of patients; 64% (27/42) of patients had a missed opportunity for colonoscopic surveillance where root-cause analyses demonstrated that 10/27 (37%) patients known to secondary care had not been offered surveillance. Four (15%) patients had a delayed diagnosis of CRC due to failure to account for previous colonoscopic findings. Seventeen (63%) patients were managed by primary care including seven patients discharged from secondary care without a surveillance plan. Matched case-control analysis did not show significant differences in cancer staging or 10-year survival outcomes.

CONCLUSION

The incidence of IBD-associated CRC has remained static. Two-thirds of patients eligible for colonoscopic surveillance had missed opportunities to diagnose CRC. Surveillance programmes without comprehensive and fully integrated recall systems across primary and secondary care are set to fail.

Real-world Effectiveness of Tofacitinib for Moderate to Severe Ulcerative Colitis: A Multicentre UK Experience

BACKGROUND

Tofacitinib is a partially selective Janus kinase inhibitor approved for the treatment of refractory moderate to severe ulcerative colitis [UC]. We sought to define the effectiveness and adverse effects of tofacitinib in a real-world cohort.

METHODS

We conducted a retrospective observational cohort study of 134 patients with UC [64% male; median age 37 years [range 16-81]; 83% of patients had previously received at least one biologic] treated with tofacitinib from October 2018 to October 2019 in four UK centres. Disease activity was assessed using the Simple Clinical Colitis Activity Index [SCCAI] or partial Mayo score [PMS], depending on study site. Response and remission were defined as a reduction in SCCAI or PMS of ≥3and SCCAI ≤2 or a PMS ≤1, respectively.

RESULTS

Overall, 74% (88/119; 95 confidence interval [CI] 65-81%] patients responded to tofacitinib at Week 8 and steroid-free remission was observed in 44% [47/108; 95% CI 3453%] patients at Week 26. Primary non-response was independently associated with younger age [p = 0.014] and higher C-reactive protein [CRP] levels at baseline [p = 0.004]. Only 23% [3/13] of patients who continued tofacitinib in the setting of primary non-response were in steroid-free remission at Week 26. Prior biologic exposure did not influence response or remission rates. Dose escalation, however, recaptured response in approximately half of patients who had lost response. Dyslipidaemia was observed in 20% [27/134; 95% CI 1428%] of patients, but adverse events necessitating drug withdrawal were uncommon and no venous thromboembolic events occurred.

CONCLUSIONS

In this multicentre real-world cohort, tofacitinib was well tolerated and clinically effective in a treatment-refractory UC population.

Quality improvement project identifies factors associated with delay in IBD diagnosis

BACKGROUND

Delay in the diagnosis of inflammatory bowel disease (IBD) is common and contemporary UK studies are lacking.

AIM

To determine factors associated with, and the consequences of, a prolonged time to diagnosis in IBD.

METHODS

This quality improvement study included 304 adults with a new IBD diagnosis made between January 2014 and December 2017 across 49 general practices (GP) and gastroenterology secondary care services. Outcome measures were demographic, clinical and laboratory factors associated with a delayed time, defined as greater than upper quartile, to: (a) patient presentation (b) GP referral (c) secondary care diagnosis, and factors associated with a complicated disease course (hospitalisation and/or surgery and/or biologic treatment) in the year after diagnosis.

RESULTS

The median [IQR] diagnosis sub-intervals were: (a) patient = 2.1 months [0.9-5.1]; (b) GP = 0.3 months [0.0-0.9]; (c) secondary care = 1.1 months [0.5-2.1]. 50% of patients were diagnosed within 4 months and 92% were diagnosed within 2 years of symptom onset. Diagnostic delay was more common in Crohn's disease (7.6 months [3.1-15.0]) than ulcerative colitis (3.3 months [1.9-7.3]) (P < 0.001). Patients who presented as an emergency (P < 0.001) but not those with a delayed overall time to diagnosis (P = 0.35) were more likely to have a complicated disease course.

CONCLUSION

Time to patient presentation is the largest component of time to IBD diagnosis. Emergency presentation is common and, unlike a delayed time to diagnosis, is associated with a complicated disease course.

Identification of a novel cyprinid herpesvirus 3 genotype detected in koi from the East Asian and South-East Asian Regions

Cyprinid herpesvirus 3 (CyHV-3) is a highly contagious virus that causes significant morbidity and mortality in common carp Cyprinus carpio L. and considered to be one of the most important pathogens of koi and common carp worldwide. Cyprinid herpesvirus 3 infected consignments imported from East Asian and South-East Asian regions were identified during quarantine period in Singapore, and virus from a 2005 consignment was successfully isolated in koi fin cells. A combination of sequence analyses and duplex PCR were used to characterize 15 CyHV-3 isolates detected in koi consignments between 2005 and 2011. Sequence analyses of the enlarged 9/5, SphI-5 and TK gene regions identified both the Asian 1 (n = 11) and European 4 (n = 4) genotypes. Duplex PCR analysis of two variable marker regions between ORF29 and ORF30 (marker I) as well as ORF133 and its upstream region (marker II) revealed viruses of genotypes J (I⁺⁺ II⁺ ), U/I (I^-- II^- ), an intermediate genotype (I⁺⁺ II^- ) and a novel genotype, I⁺⁺ II^+Δ , which was identified in viruses from seven different consignments. This novel genotype has a 13-bp deletion in marker II, while maintaining the I⁺⁺ allele of marker I. The I⁺⁺ II^+Δ genotype may have emerged from East Asian and South-East Asian regions in recent years.

The pathology of 'scale drop syndrome' in Asian seabass, Lates calcarifer Bloch, a first description

This is the first pathological description of 'scale drop syndrome' (SDS) in Asian seabass, Lates calcarifer Bloch. Cumulative mortality was estimated at 40-50%. The vasculitis in all major organs including the skin and associated tissue necrosis was distinctive. The dermis overlying scale beds was often necrotic and associated with scale loss. Necrosis of splenic ellipsoids, renal glomeruli and choroid rete glands of eye were further hallmarks of a disease with systemic vascular involvement. The brain was not spared vascular damage, and the resulting multifocal encephalomalacia probably accounts for the spiral swimming behaviour in some affected fish. Other lesions included accentuated hepatic lobulation and gastric gland necrosis. Nuclear chromatin margination and karyolysis in hepatocytes, renal tubular epithelium and gastric and intestinal epithelium suggest specific targeting of cells. Basophilic cytoplasmic inclusions were present in spleen, kidney, liver, heart and choroid rete, but they were not prominent. Using transmission electron microscopy, two morphological forms of virions were observed: single- and double-enveloped hexagonal virions. Based on size and morphology, these virions resemble iridovirus or herpesvirus. The cause of SDS is unknown, but the pathological changes, especially the vasculitis, suggest an infectious aetiology, possibly viral.

The potential of capillary birthmarks as a significant marker for capillary malformation-arteriovenous malformation syndrome in children who had nontraumatic cerebral hemorrhage

BACKGROUND/PURPOSE

Capillary malformation-arteriovenous malformation (CM-AVM) is a new autosomal dominant disorder with cutaneous capillary malformations (CM) and high-flow cerebral arteriovenous malformations (AVM). Patients may have Parkes-Weber syndrome. This study determined if cutaneous CM are a significant indicator of CM-AVM in children with cerebral bleeds.

METHODS

Children with cerebral AVMs between 1991 and 2009 were reviewed. A family history of brain hemorrhage, AVMs, or cutaneous birthmarks was elicited. Patients and siblings were examined for CM and a family tree recorded. A brief questionnaire determined the family's opinion regarding screening for this syndrome.

RESULTS

Of 30 families, 1 family had Parkes-Weber syndrome. In 3 families, both patient and relatives had CM. In 9 families, patients had no CM, but relatives had them. One family had hereditary hemorrhagic telangiectasia. From the survey, 80% of families would be concerned about vascular marks, and 87% of families would allow screening for cerebral AVMs.

CONCLUSION

A family history of vascular marks may predict families at risk of having a cerebral AVM with hemorrhage. Most families would agree to screening. However, family history and physical examination alone do not confirm CM-AVM but form a useful screening tool to identify families needing further investigations with genetic testing and/or magnetic resonance imaging.

Quantifying risk of death and disability associated with raised blood pressure

Raised blood pressure is one of the most important underlying risk factors for morbidity and mortality in the world today, ranking alongside tobacco in estimates of the worldwide attributable burden of mortality. It is a major risk factor for coronary heart disease and the major risk factor for stroke. Taken together, the cardiovascular diseases are estimated to account for some 28% of all deaths in the world. Already many more of such deaths are occurring in the developing than the developed world, and this burden of disease is set to worsen as a result of demographic changes in the poorer countries, together with adoption of Western lifestyle. The development of unfavourable blood pressure patterns in populations is a key factor underlying this worldwide epidemic. Both primary prevention (for example through improved diet) and secondary prevention (through drug treatment and non-pharmacologic approaches) are needed.

Intrauterine and life course factors in the aetiology of adult cardiovascular disease

International comparisons of age-adjusted coronary heart disease mortality show the high rates in the eastern and northern Europe, and northern Finland belongs to the areas with the highest rates. This stresses the importance of further studies on the determinants of the disease in this area. There is growing evidence to suggest that patterns of early growth and other life course factors play an important role in the origins and development of cardiovascular disease (CVD), but understanding the processes which mediate these effects is limited. Low birth weight and some other birth measures are related to increased CVD mortality, hypertension and type 2 diabetes, even though inconsistencies between and within the studies exist. With the present available evidence there is a need to address the key issues of possible confounding of perinatal and early life measures with those in later life in relation to the CVD risk. There is a need to replicate studies and establish new ones by assembling cohorts where indicators of prenatal and postnatal growth have been previously recorded drawn from different populations living under different conditions.

Vitamin C and blood pressure--an overview

BACKGROUND

Laboratory and some epidemiological studies suggest that antioxidants, such as vitamin C, are protective for cardiovascular disease. This protective effect may be mediated through blood pressure (BP). This is the first systematic review of epidemiological studies of vitamin C and BP.

METHOD

Published cross-sectional studies, prospective studies and trials in humans were identified that examined the association between vitamin C intake or plasma vitamin C levels and BP. Relevant references were located by MEDLINE search 1966-1996, EMBASE search 1980-1996, by searching personal bibliographies, books and reviews and from citations in located articles.

RESULTS

Cross-sectional data were available from 18 populations. Ten of 14 reported an inverse association between plasma vitamin C and BP and three of four reported an inverse association with vitamin C intake. The two non-randomised and four randomised controlled trials were all small. Of the randomised trials one reported a significant decrease in BP, one a non-significant decrease and two were uninterpretable.

CONCLUSIONS

We found a consistent cross-sectional association between higher vitamin C intake or status and lower BP, though no study controlled adequately for confounding by other dietary factors. Further cross-sectional studies are required to establish whether an independent association exists. If this is shown to be the case larger and longer term trials will be needed to confirm the association is causal. Potentially the impact on cardiovascular disease of a modest change in mean population vitamin C intake is large.

Urinary biochemical markers of dietary intake in the INTERSALT study

The INTERSALT Study, an international, collaborative, cross-sectional investigation of the relation between blood pressure and dietary and other factors, used quality-controlled, standardized procedures and assessment of multiple possible confounding factors to study 10,079 men and women in 52 population-based samples in 32 countries. In this study 24-h urinary excretion data were used as biochemical markers of intakes of sodium, potassium, and protein, with repeat examinations done in a randomly selected 8% of participants to asses reliability and correct for regression-dilution bias. INTERSALT showed that high salt intake, low potassium intake, excess alcohol consumption, and energy imbalance resulting in overweight are critically involved in the origins of the high blood pressure prevalent among a majority of adult populations. The findings also show that obtaining accurate estimates of associations between dietary intake and blood pressure requires large population-based samples, high-quality dietary information, control for multiple confounding variables, and modern multivariate methods of data analyses, including correction of observed associations for within-person variation in intake.

Comparative study of the T cell response to two allelic forms of a malarial vaccine candidate protein

T cell responses to two allelic forms of the merozoite surface Ag 2 (MSA2) of Plasmodium falciparum were mapped in mice using the rMSA2 proteins, Ag 1609 which has the sequence of the FCQ27/PNG strain and Ag 1615 which has the sequence of the Indochina 1 strain. Lymph node cells of BL/10 and B10.BR mice immunized with either Ag 1609 or Ag 1615 responded to both Ag in in vitro proliferation assays. Lymph node cells of BALB/c mice did not respond. The T cell determinants recognized by the responder strains were mapped to conserved and variant regions of these Ag using overlapping synthetic peptides. The determinants recognized by each mouse strain were distinct. Marked difference in sequence between the central regions of the two rMSA2 proteins did not affect antigenic processing of the conserved N and C terminal regions. Hence lymph node cells of BL/10 mice immunized with either Ag 1615 or Ag 1609 recognized an immunodominant T cell determinant at the highly conserved N terminal end within the sequence YSNTFINNAYNMSIR (peptide 3b) and B10.BR mice similarly immunized recognized an immunodominant determinant at the highly conserved C terminal within the sequence CTDGNKENCGAATSL (peptide 23). Several peptides identified as containing immunodominant T cell determinants specific to BL/10 mice induced peptide-specific T cells in both BL/10 and B10.BR mouse strains when used as immunogens. However, the ability of the peptide-primed T cells to proliferate in response to the rMSA2 proteins was confined to BL/10 mice. An example of this was observed with peptides 3b and N (KNESKYSNTFINNAYNMSIRRSMAN). Peptide N was able to prime B10.BR and BL/10 mice for an enhanced antibody response when these mice were subsequently immunized with Ag 1615 even though Ag 1615-specific T cell proliferation was not detected in B10.BR mice primed with N. The study concluded that 1) conserved sequences such as peptide N when used in vaccines may give rise to MSA2-specific memory Th cells amenable to boosting by subsequent exposure to all parasite strains and 2) peptide priming may be a useful pathway for inducing defined memory Th cells in a wider population and for preferentially inducing T dependent over T independent responses to some malarial Ag.

Comparative study of the T cell response to two allelic forms of a malarial vaccine candidate protein

T cell responses to two allelic forms of the merozoite surface Ag 2 (MSA2) of Plasmodium falciparum were mapped in mice using the rMSA2 proteins, Ag 1609 which has the sequence of the FCQ27/PNG strain and Ag 1615 which has the sequence of the Indochina 1 strain. Lymph node cells of BL/10 and B10.BR mice immunized with either Ag 1609 or Ag 1615 responded to both Ag in in vitro proliferation assays. Lymph node cells of BALB/c mice did not respond. The T cell determinants recognized by the responder strains were mapped to conserved and variant regions of these Ag using overlapping synthetic peptides. The determinants recognized by each mouse strain were distinct. Marked difference in sequence between the central regions of the two rMSA2 proteins did not affect antigenic processing of the conserved N and C terminal regions. Hence lymph node cells of BL/10 mice immunized with either Ag 1615 or Ag 1609 recognized an immunodominant T cell determinant at the highly conserved N terminal end within the sequence YSNTFINNAYNMSIR (peptide 3b) and B10.BR mice similarly immunized recognized an immunodominant determinant at the highly conserved C terminal within the sequence CTDGNKENCGAATSL (peptide 23). Several peptides identified as containing immunodominant T cell determinants specific to BL/10 mice induced peptide-specific T cells in both BL/10 and B10.BR mouse strains when used as immunogens. However, the ability of the peptide-primed T cells to proliferate in response to the rMSA2 proteins was confined to BL/10 mice. An example of this was observed with peptides 3b and N (KNESKYSNTFINNAYNMSIRRSMAN). Peptide N was able to prime B10.BR and BL/10 mice for an enhanced antibody response when these mice were subsequently immunized with Ag 1615 even though Ag 1615-specific T cell proliferation was not detected in B10.BR mice primed with N. The study concluded that 1) conserved sequences such as peptide N when used in vaccines may give rise to MSA2-specific memory Th cells amenable to boosting by subsequent exposure to all parasite strains and 2) peptide priming may be a useful pathway for inducing defined memory Th cells in a wider population and for preferentially inducing T dependent over T independent responses to some malarial Ag.

The incidence of adrenal and other antibodies in the sera of patients with idiopathic adrenal insufficiency (Addison's disease)

The histories of 118 (sixty-one males, fifty-seven females) with idiopathic Addison's disease were reviewed and their sera tested for adrenal, thyroid, gastric and parathyroid antibodies. Adrenal antibodies were found in approximately 50% of patients with idiopathic Addison's disease. The majority of these patients, particularly the females, had an associated diagnosed disease. Studies of antibodies to various tissues is of assistance in detecting the frequent sub-clinical occurrence of other diseases in idiopathic Addison's disease. The onset of idiopathic Addison's disease in sixty-four of the group was during adult life, in forty-seven during childhood, and in seven was not known. In fifty-one the diagnosis of an associated disease had been made (hypoparathyroidism, eighteen; pernicious anaemia, seven; moniliasis, seven; diabetes, ten; cirrhosis, two; alopecia, three; thyroid disease, thirty). A further twenty-four patients had antibodies to gastric, thryoid or parathyroid tissue. The finding of an associated disease, or antibody other than adrenal, was greatest in adult females (thirty-three of thirty-nine), frequent in female children (thirteen of seventeen), less common in adult males (eleven of twenty-five) and least in male children (thirteen of thirty). Only forty-three of the group had no evidence of an associated disease. Adrenal antibodies were found in fifty-seven of the 118 patients studied, occurring most frequently in females with a diagnosed associated disease (twenty-three of thirty), and least commonly in males without an associated disease (seven of forty).

The incidence of parathyroid and other antibodies in the sera of patients with idiopathic hypoparathyroidism

Parathyroid antibodies were demonstrated in 38% of seventy-four patients with idiopathic hypoparathyroidism, 26% of ninety-two patients with idiopathic Addison's disease, 12% of forty-nine patients with Hashimoto's thyroiditis, and in 6% of 245 control patients. A significant percentage of patients with idiopathic hypoparathyroidism also had adrenal, thyroid and/or gastric parietal cell antibodies, even in the absence of diagnosed Addison's disease, thyroid disease, or pernicious anaemia. The antibody(s) against parathyroid tissue are not against parathyroid hormone, and do not cross-react in absorption studies with gastric, thyroid, adrenal, liver or kidney tissue. Species specificity was not investigated. The diagnostic and theoretic considerations are presented.