What interval between colorectal cancer resection and first surveillance colonoscopy? An audit of practice and yield.

AIM: Colonoscopic follow-up after colorectal cancer resection (CRC) is recommended to screen for anastomotic recurrence and metachronous neoplasia, although guidelines vary in the timings of the first investigation. We aimed to quantify current practice and yield of neoplasia at first colonoscopy in relation to time from original resection. METHOD: We conducted a retrospective case note study of all CRCs treated with curative intent within our hospital between two time periods: 2001-2003 and 2006-2007. Variables collected were the extent of preoperative luminal imaging, tumour site, procedure, timing and findings of initial colonoscopy, postoperative CT findings and mortality. The first follow-up colonoscopy findings including neoplasia formation and recurrence rates were matched with rates of complete preoperative luminal imaging. Two-year and 5-year outcomes were sought. RESULTS: A total of 863 patients underwent CRC with curative intent within these two time periods (518 vs 345). Colonoscopic follow-up rates by 2 years were 32.8%vs 54.1%. Within the first cohort 63.5% of patients underwent colonoscopy by 5 years. Significant volumes of neoplasia and resectable recurrences were found before 2 years within these groups. Earlier detection of recurrent malignancy was associated with an improved patient outcome. Complete preoperative screening of the bowel was not associated with a lower incidence of neoplasia at first postoperative colonoscopy. CONCLUSION: Our study demonstrates significant colonoscopic detection rates of neoplasia within 2 years of CRC. Patient outcomes were improved with earlier detection. We would therefore suggest an interval of no more than 2 years between resection and first surveillance colonoscopy.

Hereditary hepatic and systemic amyloidosis caused by a new deletion/insertion mutation in the apolipoprotein AI gene.

We report a Spanish family with autosomal-dominant non-neuropathic hereditary amyloidosis with a unique hepatic presentation and death from liver failure, usually by the sixth decade. The disease is caused by a previously unreported deletion/insertion mutation in exon 4 of the apolipoprotein AI (apoAI) gene encoding loss of residues 60-71 of normal mature apoAI and insertion at that position of two new residues, ValThr. Affected individuals are heterozygous for this mutation and have both normal apoAI and variant molecules bearing one extra positive charge, as predicted from the DNA sequence. The amyloid fibrils are composed exclusively of NH2-terminal fragments of the variant, ending mainly at positions corresponding to residues 83 and 92 in the mature wild-type sequence. Amyloid fibrils derived from the other three known amyloidogenic apoAI variants are also composed of similar NH2-terminal fragments. All known amyloidogenic apoAI variants carry one extra positive charge in this region, suggesting that it may be responsible for their enhanced amyloidogenicity. In addition to causing a new phenotype, this is the first deletion mutation to be described in association with hereditary amyloidosis and it significantly extends the value of the apoAI model for investigation of molecular mechanisms of amyloid fibrillogenesis.

SAA1 alleles as risk factors in reactive systemic AA amyloidosis.

SAA1 is the predominant isoform of acute phase human SAA deposited as AA amyloid fibrils in reactive systemic amyloidosis. It has recently been reported that in the Japanese population, in whom the SAA1 gamma allele occurs with a frequency of 37%, possession of, and especially, homozygosity for this allele is a significant risk factor for AA amyloidosis in adult patients with rheumatoid arthritis (RA). In contrast we report here that in a control sample of 95 healthy adult male Caucasians the SAA1 gamma allele occurs at the much lower frequency of 5.3% and that, among 41 patients with juvenile chronic arthritis (JCA) and AA amyloidosis, there was a highly significantly increased frequency of the SAA1 alpha allele (90.2%), and particularly homozygosity for this allele (80.5%), compared both to the healthy controls (75.8% and 57.9% respectively) and to 8 JCA cases without amyloid (56.3% and 12.5%). A similar trend with respect to frequency of the SAA1 alpha allele and homozygosity for it was observed among 26 adult Caucasian RA patients with AA amyloid and 26 such cases without amyloid, although it did not reach statistical significance. These results suggest that there is probably differential amyloidogenicity amongst the different SAA1 isoforms and indicate that homozygosity for SAA1 alpha and SAA1 gamma in the different populations is a significant risk factor for development of AA amyloidosis. In Caucasian patients with JCA, the presence of the homozygous SAA1 alpha genotype indicates high risk of amyloidosis and should encourage early and aggressive anti-inflammatory therapy to keep circulating SAA levels as low as possible.

Pyrin/marenostrin mutations in familial Mediterranean fever.

Familial Mediterranean fever (FMF) is an inherited inflammatory disease that is frequently complicated by reactive systemic (AA) amyloidosis. It is principally recognized in certain Mediterranean populations, and the diagnosis depends on clinical features. Four mutations strongly linked to FMF have lately been identified in a gene encoding a novel protein that has been named pyrin or marenostrin. We studied 27 consecutive patients of varied ethnic origin, including an English man, who had classical, probable or possible FMF. Pyrin/marenostrin genotypes were determined, and AA amyloidosis was sought using serum amyloid P component scintigraphy. Among the 23 patients with classical or probable FMF, 17 were homozygotes or compound heterozygotes for pyrin/marenostrin mutations, and in five, only single allele mutations were identified. Two new mutations, T6811 and delta M694, were discovered in addition to the four described previously. No mutations were identified in three of the four patients with possible FMF. Nine patients had AA amyloidosis, but this association was not restricted to any particular genotype. Most patients with FMF have mutations in both pyrin/marenostrin alleles, and genotyping at this locus is a valuable diagnostic test. Unidentified second mutations are likely to occur in FMF patients who have apparently solitary mutations, and therefore genotype results must be interpreted in conjunction with the clinical picture.

Prevalence and significance of the familial Mediterranean fever gene mutation encoding pyrin Q148.

Familial Mediterranean fever (FMF) is caused by more than 25 mutations in the gene MEFV, which encodes pyrin (marenostrin), a protein implicated in the regulation of neutrophil activity. Pyrin Q148, is one of the five most common variants in populations in which FMF typically occurs. Our identification of the pyrin Q148 allele in several patients from ethnic groups in which FMF is not classically recognized who had longstanding fevers or AA amyloidosis prompted us to study the prevalence of pyrin Q148 in healthy British, Indian and Chinese subjects. The gene frequency was also sought in 50 British Caucasian patients with inflammatory arthritis, 25 of whom had AA amyloidosis, five Punjabi Indians with AA amyloidosis complicating inflammatory arthritis, and seven British Caucasian patients with uncharacterized longstanding fever syndromes. The allele frequency for pyrin Q148 was 21%, 15% and 0%, respectively, among Punjabi Indian, Chinese and Caucasian British controls, and was significantly increased among the patients with AA amyloidosis and the patients with obscure fever syndromes (p<0.01). Pyrin Q148 is a polymorphism and occurs widely in global terms, and, although it may cause FMF when associated with certain other MEFV mutations, homozygosity for Q148 alone must usually be insufficient to produce FMF in the populations studied. The association of pyrin Q148 with AA amyloidosis and with obscure chronic inflammatory diseases suggests the variant may augment inflammation non-specifically, which might have been beneficial during evolution, but could potentially exacerbate many chronic inflammatory disorders.

The genetic basis of autosomal dominant familial Mediterranean fever.

Familial Mediterranean fever (FMF) is classically an autosomal recessive periodic inflammatory disease occurring in Mediterranean and Middle Eastern populations. It is caused by mutations affecting both alleles of MEFV, a gene that encodes pyrin (marenostrin), an uncharacterized neutrophil protein. Occasional reports of autosomal dominant FMF have often been discounted, on the basis that asymptomatic FMF carriers are common in certain populations, and give rise to pseudo-dominant inheritance. We performed comprehensive MEFV genotyping in five families in whom FMF appeared to be inherited dominantly. Transmission proved to be pseudo-dominant in two cases, but true dominant inheritance of FMF with variable penetrance was supported by the genotyping results in the other three families. The disease in these cases was associated with heterozygosity for either pyrin DeltaM694 alone or the compound pyrin variant E148Q/M694I, the latter occurring in two unrelated families. Complete MEFV sequencing failed to identify any coding region abnormality in the other allele in any of these cases, and, in the largest kindred, single-allele disease transmission was further supported by analysis of silent single nucleotide polymorphisms, which proved that affected individuals had at least three different complementary alleles. Studies of two further unrelated British patients with FMF associated with simple heterozygosity for pyrin DeltaM694 were also consistent with autosomal dominant inheritance. The clinical features of dominantly inherited FMF were absolutely typical, including AA amyloidosis in a patient with pyrin DeltaM694. These findings extend the spectrum of FMF, and suggest that the methionine residue at position 694 makes a crucial contribution to pyrin's function, and that a 50% complement of normal pyrin activity does not prevent susceptibility to FMF.

A new apolipoprotein Al variant, Trp50Arg, causes hereditary amyloidosis.

A man with hereditary non-neuropathic systemic amyloidosis had amyloid fibril protein subunits consisting of N-terminal fragments (residues 1-86, 1-92 and 1-93) of a previously unknown variant of apolipoprotein Al, Trp50Arg, encoded by a thymine-cytosine transition. This is the third reported amyloidogenic apoAl variant. All involve substitutions of single neutral amino acids by the cationic residue arginine, suggesting a common mechanism of amyloidogenesis. However, the phenotypic expression of these mutations varies both within and between the seven known families with hereditary apoAl amyloidosis. These findings should facilitate analysis of the molecular basis of fibrillogenesis and of factors that modulate amyloid deposition and its consequences in vivo.

The interaction of zinc oxide-based dental cements with aqueous solutions of potassium fluoride.

The ability of zinc oxide-based dental cements (zinc phosphate and zinc polycarboxylate) to take up fluoride from aqueous solution has been studied. Only zinc phosphate cement was found to take up any measurable fluoride after 5 h exposure to the solutions. The zinc oxide filler of the zinc phosphate also failed to take up fluoride from solution. The key interaction for this uptake was thus shown to involve the phosphate groups of the set cement. However, whether this took the form of phosphate/fluoride exchange, or the formation of oxyfluoro-phosphate groups was not clear. Fluoride uptake followed radicaltime kinetics for about 2 h in some cases, but was generally better modelled by the Elovich equation, dq(t)/dt = alpha exp(-betaq(t)). Values for alpha varied from 3.80 to 2.48 x 10(4), and for beta from 7.19 x 10(-3) to 0.1946, though only beta showed any sort of trend, becoming smaller with increasing fluoride concentration. Fluoride was released from the zinc phosphate cements in processes that were diffusion based up to M(t)/M(infinity) of about 0.4. No further release occurred when specimens were placed in fresh volumes of deionised water. Only a fraction of the fluoride taken up was re-released, demonstrating that most of the fluoride taken up becomes irreversibly bound within the cement.

Clinical and subclinical inflammation in patients with familial Mediterranean fever and in heterozygous carriers of MEFV mutations.

OBJECTIVE: To prospectively monitor inflammatory activity over a prolonged period in a cohort of Turkish patients with FMF, their healthy relatives and healthy controls and to relate this to their MEFV genotypes. METHODS: 43 patients with FMF and 75 of their asymptomatic relatives underwent fortnightly assessments and venesection for measurement of CRP and SAA over 5 months. 50 unrelated healthy population matched controls were also studied. MEFV genotyping was performed on all participants and comparisons were made between the different groups. RESULTS: Paired MEFV mutations were detected in 84% of FMF patients and single mutations in 12%. Substantial acute phase reactivity was seen among the patients with FMF during attacks (median SAA 693 mg/l, CRP 115 mg/l). Between attacks there was also some inflammatory activity (median SAA 6 mg/l, CRP 4 mg/l). Among healthy controls 16% were heterozygotes for MEFV mutations and 4% had two mutations. As expected there was a substantial carrier rate among healthy relatives with mutations detected in almost 92%. Asymptomatic MEFV heterozygotes had elevated acute phase proteins compared to wild type subjects. CONCLUSION: Substantial sub-clinical inflammation occurs widely and over prolonged periods in patients with FMF, indicating that the relatively infrequent clinically overt attacks represent the 'tip of the iceberg' in this disorder. Both basal and peak acute phase protein concentrations were greater in MEFV heterozygotes than in wild-type controls, regardless of mutation demonstrating a 'pro-inflammatory' phenotype among FMF carriers. Upregulation of the acute phase response among carriers of FMF may augment their innate host response and contribute to better resistance to infection.

Binding of pentraxins to different nuclear structures: C-reactive protein binds to small nuclear ribonucleoprotein particles, serum amyloid P component binds to chromatin and nucleoli.

Binding of the human pentraxin plasma proteins, C-reactive protein (CRP) and serum amyloid P component (SAP), to the nuclei of human cells was studied using whole acute phase serum as the source of the proteins and confocal immunofluorescence microscopy. CRP and SAP clearly bound to distinct, different structures. Double staining with MoAbs to the Sm D and Sm B/B' components of small nuclear ribonucleoproteins confirmed that CRP bound exclusively to these particles. As expected, SAP bound to chromatin and, in addition, binding to the nucleolus was observed for the first time. These interactions demonstrated under relatively physiological conditions, with native pentraxins unseparated from serum and with nuclear constituents in situ, are likely to be of functional importance in vivo.

Familial nephropathic systemic amyloidosis caused by apolipoprotein AI variant Arg26.

A point mutation in the apolipoprotein AI (apoAI) gene causing autosomal dominant non-neuropathic systemic amyloidosis is described in a previously unreported Canadian family of British origin with five affected individuals in three generations. Amyloid deposits in the renal biopsy from the proband, a 31-year-old female presenting with hypertension and renal failure, stained immunospecifically with antiserum to apoAI. The plasma of all family members with amyloidosis contained both wild-type apoAI and a variant bearing one additional positive charge. Sequencing of the apoAI gene demonstrated that the proband was a heterozygote for a single base substitution in exon 3, changing codon 26 from GGC(Gly) to CGC(Arg). Concordance of the mutant allele with the presence of variant plasma apoAI and clinical features of amyloidosis was demonstrated. This is the third family in which this amyloidotic mutation has been described, but the distribution of amyloid deposits and their clinical effects are clearly determined by other genetic and/or environmental factors.

Apolipoprotein AI mutation Arg-60 causes autosomal dominant amyloidosis.

A mutation in the gene for apolipoprotein AI (apoAI) was identified in an English family with autosomal dominant non-neuropathic systemic amyloidosis. The plasma of all affected individuals contained a variant apoAI with one additional charge, as well as normal apoAI. The propositus was heterozygous; the coding region of his apoAI gene contained both the normal sequence and a single-base substitution changing the codon for residue 60 of the mature protein from CTG (leucine) to CGG (arginine). Allele-specific oligonucleotide hybridization showed that the other affected individuals were also heterozygotes and that there was concordance of the mutant allele with the presence of variant plasma apoAI. Amyloid fibrils isolated from the spleen of the propositus consisted of proteins that ran as a doublet with an apparent mass of approximately 10 kDa in SDS/PAGE and a trace band at 28 kDa. Electrospray mass spectrometry of the purified 10-kDa material revealed components with mass corresponding to the N-terminal 88, 92, 93, and 94 residues of apoAI each with substitution of arginine for leucine. These observations were confirmed by direct protein sequencing and laser desorption time-of-flight mass analysis. No material with the normal apoAI sequence was detected. The trace band at 28 kDa yielded the N-terminal sequence of mature apoAI, indicating that intact or minimally degraded apoAI was also present in the fibril preparation. Discovery of this mutation and the detailed characterization of the apoAI fragments that form the amyloid fibrils open additional avenues for investigation of amyloidogenesis.

Hereditary nephropathic systemic amyloidosis caused by a novel variant apolipoprotein A-I.

We report a family with autosomal-dominant hereditary systemic amyloidosis in three generations, presenting with renal involvement. Two members of the current generation received renal transplants for end-stage renal failure 16 and 18 years ago, and remain very well clinically despite massive visceral amyloidosis. Two other members of this generation, aged 32 and 47 years, have massive systemic amyloid but no clinical disability. Individuals known to be affected in previous generations died of renal failure in early adult life. Amyloid deposits in the proband, one of the transplanted individuals, were composed of apolipoprotein A-I (apoA-I), and among living family members there was complete concordance between amyloidosis and the presence of a novel 9 base pair in-frame deletion mutation in exon 4 of the apoA-I gene, causing a loss of residues Glu70Phe71Trp72. This predicts the acquisition of a single extra positive charge by mature apoA-I, and this variant was detected in the plasma of all carriers. All the previously reported amyloidogenic variants of apoA-I also carry an extra positive charge, indicating that this electrostatic change is likely to be relevant to the amyloidogenicity of apoA-I.

Transthyretin Ile73Val is associated with familial amyloidotic polyneuropathy in a Bangladeshi family. Mutations in brief no. 158. Online.

Amyloidosis is characterised by the extraceullular deposition of certain different proteins in a distinctively abnormal fibrillar conformation. All types of amyloid fibril share remarkably similar structural and biophysical properties despite substantial chemical heterogeneity among their respective precursor proteins. Hereditary amyloidosis associated with genetically determined protein variants is rare, but is extremely important as a model for studying the pathogenesis of amyloidosis generally. We report a novel mutation of the transthyretin (TTR) coding for TTR Ile73Val which is associated with familial amylodotic polyneuropathy (FAP) in a Bangladeshi family. The mutation was detected by direct sequencing of the PCR-amplified TTR exons. It creates an additional Accl restriction exzyme site in exon 3, allowing confirmation of its presence by RFLP. Amyloid detected in sural nerve and colonic biopsies was shown to be composed of TTR by immunohistochemistry. The predominant clinical features were progressive autonomic and sensori-motor peripheral neuropathy, beginning at age 50 years. The proband's father and two siblings had similar illnesses. These findings indicate Val73 is an amyloidogenic variant of TTR.

Transthyretin Leu12Pro is associated with systemic, neuropathic and leptomeningeal amyloidosis.

We report a middle-aged woman with a novel transthyretin (TTR) variant, Leu12Pro. She had extensive amyloid deposition in the leptomeninges and liver as well as the involvement of the heart and peripheral nervous system which characterizes familial amyloid polyneuropathy caused by variant TTR. Clinical features attributed to her leptomeningeal amyloid included radiculopathy, central hypoventilation, recurrent subarachnoid haemorrhage, depression, seizures and periods of decreased consciousness. MRI showed a marked enhancement throughout her meninges and ependyma, and TTR amyloid deposition was confirmed by meningeal biopsy. The simultaneous presence of extensive visceral amyloid and clinically significant deposits affecting both the peripheral and central nervous system extends the spectrum of amyloid-related disease associated with TTR mutations. The unusual association of severe peripheral neuropathy with symptoms of leptomeningeal amyloid indicates that leptomeningeal amyloidosis should be considered part of the syndrome of TTR-related familial amyloid polyneuropathy.

Molecular mechanisms of fibrillogenesis and the protective role of amyloid P component: two possible avenues for therapy.

Amyloid deposits regress when the supply of fibril precursor proteins is sufficiently reduced, indicating that amyloid fibrils are degradable in vivo. Serum amyloid P component (SAP), a universal constituent of amyloid deposits, efficiently protects amyloid fibrils from proteolysis in vitro, and may contribute to persistence of amyloid in vivo. Drugs that prevent binding of SAP to amyloid fibrils in vivo should therefore promote regression of amyloid and we are actively seeking such agents. A complementary strategy is identification of critical molecular processes in fibrillogenesis as targets for pharmacological intervention. All amyloidogenic variants of apolipoprotein AI contain an additional positive charge in the N-terminal fibrillogenic region of the protein. This is unlikely to be a coincidence and should be informative about amyloidogenesis by this protein. The two amyloidogenic variants of human lysozyme, caused by the first natural mutations found in its gene, provide a particularly powerful model system because both the crystal structure and folding pathways of wild-type lysozyme are so well characterized. The amyloidogenic variant lysozymes have similar 3D crystal structures to the wild type, but are notably less thermostable. They unfold on heating, lose enzymic activity, and aggregate to form amyloid fibrils in vitro.