Infliximab vs. adalimumab in Crohn's disease: results from 327 patients in an Australian and New Zealand observational cohort study

BACKGROUND

Maintenance anti-tumour necrosis factor-α (anti-TNFα) treatment for Crohn's disease is the standard of care for patients with an inadequate response to corticosteroids and immunomodulators.

AIM

To compare the efficacy and safety of infliximab and adalimumab in clinical practice and assess the value of concomitant immunomodulator therapy.

METHODS

We performed an observational cohort study in consecutive patients with Crohn's disease qualifying for anti-TNFα treatment in Australia and New Zealand between 2007 and 2011. Demographic and clinical data were prospectively recorded to identify independent factors associated with induction and maintenance of response to infliximab or adalimumab, or to either anti-TNFα therapy.

RESULTS

Three hundred and twenty-seven patients (183 infliximab, 144 adalimumab) successfully applied for treatment. Eighty-nine percent responded in all groups and median maintenance of response was similar for the two agents. Concomitant immunomodulator with infliximab, but not adalimumab, demonstrated a significantly longer response overall (P = 0.002), and significantly fewer disease and treatment-related complications (P = 0.017). Corticosteroids at baseline, and/or in the preceding 12 months, were associated with a 9-13 times greater risk of disease flare during maintenance treatment as compared to no corticosteroids (P < 0.0001). Maintenance of response was similar in the anti-TNF naïve and anti-TNF experienced subgroups.

CONCLUSIONS

In this large, real-life study, we demonstrate infliximab and adalimumab to have similar response characteristics. However, infliximab requires concomitant immunomodulator to achieve optimal maintenance of response comparable to adalimumab monotherapy. The results of this study will assist clinicians in further optimising patient care in their day-to-day clinical practice.

Crohn's disease and smoking: is it ever too late to quit?

BACKGROUND

Smoking increases CD risk. The aim was to determine if smoking cessation at, prior to, or following, CD diagnosis affects medication use, disease phenotypic progression and/or surgery.

METHODS

Data on CD patients with disease for ≥5 yrs were collected retrospectively including the Montreal classification, smoking history, CD-related abdominal surgeries, family history, medication use and disease behaviour at diagnosis and the time when the disease behaviour changed.

RESULTS

1115 patients were included across six sites (mean follow-up-16.6 yrs). More non-smokers were male (p=0.047) with A1 (p<0.0001), L4 (p=0.028) and perianal (p=0.03) disease. Non-smokers more frequently received anti-TNF agents (p=0.049). (p=0.017: OR 2.5 95%CI 1.18-5.16) and those who ceased smoking prior to diagnosis (p=0.045: OR 2.3 95%CI 1.02-5.21) progressed to complicated (B2/B3) disease as compared to those quitting at diagnosis. Patients with uncomplicated terminal ileal disease at diagnosis more frequently developed B2/B3 disease than isolated colonic CD (p<0.0001). B2/B3 disease was more frequent with perianal disease (p<0.0001) and if i.v. steroids (p=0.004) or immunosuppressants (p<0.0001) were used. 49.3% (558/1115) of patients required at least one intestinal surgery. More smokers had a 2nd surgical resection than patients who quit at, or before, the 1st resection and non-smokers (p=0.044: HR=1.39 95%CI 1.01-1.91). Patients smoking >3 cigarettes/day had an increased risk of developing B2/B3 disease (p=0.012: OR 3.8 95%CI 1.27-11.17).

CONCLUSION

Progression to B2/B3 disease and surgery is reduced by smoking cessation. All CD patients regardless of when they were diagnosed, or how many surgeries, should be strongly encouraged to cease smoking.

Self-processing 2A-polyproteins--a system for co-ordinate expression of multiple proteins in transgenic plants

Achieving co-ordinate, high-level and stable expression of multiple transgenes in plants is currently difficult. Expression levels are notoriously variable and influenced by factors that act independently on transgenes at different genetic loci. Instability of expression due to loss, re-arrangement or silencing of transgenes may occur, and is exacerbated by increasing numbers of transgenic loci and repeated use of homologous sequences. Even linking two or more genes within a T-DNA does not necessarily result in co-ordinate expression. Linking proteins in a single open reading frame--a polyprotein--is a strategy for co-ordinate expression used by many viruses. After translation, polyproteins are processed into constituent polypeptides, usually by proteinases encoded within the polyprotein itself. However, in foot-and-mouth disease virus (FMDV), a sequence (2A) of just 16-20 amino acids appears to have the unique capability to mediate cleavage at its own C-terminus by an apparently enzyme-independent, novel type of reaction. This sequence can also mediate cleavage in a heterologous protein context in a range of eukaryotic expression systems. We have constructed a plasmid in which the 2A sequence is inserted between the reporter genes chloramphenicol acetyltransferase (CAT) and beta-glucuronidase (GUS), maintaining a single open reading frame. Here we report that expression of this construct in wheatgerm lysate and transgenic plants results in efficient cleavage of the polyprotein and co-ordinate expression of active CAT and GUS. Self-processing polyproteins using the FMDV 2A sequence could therefore provide a system for ensuring co-ordinated, stable expression of multiple introduced proteins in plant cells.

Histological and electron microscopic analysis of tissue response to synthetic composite bone graft in the canine

A synthetic composite bone graft material, composed of fibrillar collagen, hydroxyapatite, and tricalcium phosphate, was evaluated in canine femoral shaft defects and compared to ungrafted defects and defects grafted with autogenous bone. The results of mechanical testing of the grafted femora in torsion at 1 year postoperatively were previously reported. This report details the histological and microscopic features of the graft sites. The results of this study suggest that the healing of the graft site is not yet complete at 1 year and that healing may be more complete in defects that received the synthetic graft as compared to ungrafted sites and autogenous bone graft. The bone tissue appears to respond to the graft particles as if they were bone particles.

Control of gene expression in plant cells using a 434:VP16 chimeric protein

The herpes simplex virus type 1 VP16 polypeptide is a potent trans-activator of viral gene expression. We have tested the ability of the VP16 activation domain to activate gene expression in plant cells. A plasmid encoding a translational fusion between the full-length 434 repressor and the C-terminal 80 amino acids of VP16, was constructed. When expressed in Escherichia coli, the chimeric protein binds efficiently to 434-binding motifs (operators). For expression in plant cells, the chimeric activator gene was placed between the cauliflower mosaic virus (CaMV) 35S promoter and nos terminator sequences in a pUC-based plasmid. The 434 operators were placed upstream of a minimal CaMV 35S promoter linked to the E. coli gus reporter gene. This reporter-expression cassette was then incorporated into the same plasmid as the 434 cI/VP16 activator-expression cassette. Two control plasmids were also constructed, one encoding the 434 protein with no activator domain and the second a chimeric activator with no DNA-binding domain. The chimeric activator was tested for its ability to activate gene expression in a tobacco protoplast transient assay system. Results are presented to show that we can obtain in plant cells significant activation of gene expression that is dependent on both DNA-binding and the presence of the activator domain.

Simultaneous asymmetric bilateral traumatic hip dislocation

A 25-year-old man presented to the emergency department with simultaneous right anterior and left posterior hip dislocations resulting from a motor vehicle accident. Simultaneous bilateral traumatic hip dislocation is an uncommon occurrence. More rare is asymmetric simultaneous bilateral hip dislocation, with only ten cases documented in the English-language literature. The importance of an anteroposterior pelvic radiograph after significant major trauma is emphasized. Several serious complications can be associated with this condition, so expeditious management in the ED is warranted.

The Escherichia coli LexA repressor-operator system works in mammalian cells

We have demonstrated the use of the Escherichia coli LexA repressor-operator system to down-regulate gene expression in mouse cells. The LexA gene was placed downstream of the RSVLTR promoter with polyadenylation and splice signals from SV40. This expression unit was introduced into mouse Ltk- cells by calcium phosphate transfection and stable transfectants selected which express LexA protein. We have used the bacterial chloramphenicol acetyltransferase gene (CAT) as our reporter gene. Transcription of this gene was driven by the HSV tk promoter, into which we have introduced one or two synthetic LexA operator sequences in various positions throughout the promoter. Necessary 3' signals were from the HSV tk gene. Repression by LexA was assessed by comparing the transient expression of tkCAT target constructs, containing LexA operator sequences in the promoter, in cells expressing LexA protein with that in control cells not expressing the repressor. We have observed up to 10-fold repression of CAT expression in LexA+ cells from promoters containing LexA operator sequences.