Semiphysiologically Based Pharmacokinetic Model of Leflunomide Disposition in Rheumatoid Arthritis Patients.

A semiphysiologically based pharmacokinetic (semi-PBPK) population model was used to evaluate the influence of enterohepatic recycling and protein binding, as well as the effect of genetic variability in CYP1A2, CYP2C19, and ABCG2, on the large interindividual variability of teriflunomide (active metabolite) concentrations following leflunomide administration in rheumatoid arthritis (RA) patients. The model was developed with total and free teriflunomide concentrations determined in RA patients taking leflunomide, as well as mean teriflunomide concentrations following the administration of leflunomide or teriflunomide extracted from the literature. Once developed, the 15-compartment model was able to predict total and free teriflunomide concentrations and was used to screen demographic and genotypic covariates, of which only fat-free mass and liver function (ALT) improved prediction. This approach effectively evaluated the effects of multiple covariates on both total and free teriflunomide concentrations, which have only been explored previously through simplistic one-compartment models for total teriflunomide.

The rheumatoid arthritis susceptibility polymorphism PTPN22 C1858T is not associated with leflunomide response or toxicity.

WHAT IS KNOWN AND OBJECTIVE: A common polymorphism (C1858T) in the gene that encodes the protein tyrosine phosphatase non-receptor type 22 (PTPN22) is associated with altered T-cell responses and increased susceptibility to rheumatoid arthritis (RA) and other autoimmune diseases. Teriflunomide, the active metabolite of leflunomide, reduces T-cell responses through inhibition of tyrosine kinase p56LCK. We examined a potential association between PTPN22 genotype and response or toxicity to leflunomide in Caucasian RA patients taking leflunomide in combination with other disease-modifying antirheumatic drugs (DMARDs). METHODS: Patients enrolled in the Royal Adelaide Hospital RA inception cohort and taking leflunomide were eligible for inclusion. Participants were followed for 12 months after leflunomide initiation or until either another DMARD was added or leflunomide was ceased. Clinical response according to change in 28-joint Disease Activity Score (DAS28) and cessation due to toxicity were assessed. RESULTS AND DISCUSSION: A total of 94 participants were included in the study, 75 of whom carried the CC genotype, 18 the CT, whereas one individual carried the TT genotype. Over the first 12 months of leflunomide treatment, there was no statistically significant relationship between carrying the T allele and change in DAS28 (-0·84 vs. -1·15, P = 0·446) nor with cessation of leflunomide treatment due to side effects (P = 0·433). These results indicate that PTPN22 C1858T genotype has no effect on response or toxicity outcomes in leflunomide-treated RA patients. WHAT IS NEW AND CONCLUSION: This is the first study to evaluate the biologically plausible hypothesis that PTPN22 genotype might be a predictor of response/toxicity to leflunomide therapy. Despite this, PTPN22 genotype was not associated with leflunomide response or toxicity in patients with RA.

Pharmacogenomics of NAT2 and ABCG2 influence the toxicity and efficacy of sulphasalazine containing DMARD regimens in early rheumatoid arthritis.

Sulphasalazine (SSA) is a disease modifying anti-rheumatic drug (DMARD) that is commonly used to treat rheumatoid arthritis (RA). Plasma levels of SSA and its metabolite sulphapyridine are influenced by common polymorphisms in genes that encode N-acetyl transferase 2 (NAT2) and ATP-binding cassette protein G2 (ABCG2). Study participants had early RA that was treated with a combination DMARD regimen that included SSA. Toxicity was defined by cessation of SSA due to adverse effects and response as remission after 12 months of treatment. The effect of variables on toxicity was assessed by a Cox-proportional Hazard model and response by logistic regression. After correction for conventional variables, toxicity in 229 participants was influenced by NAT2 phenotype (hazard ratio=1.74 (95% confidence interval (CI) 1.01-3.21), P=0.044) and remission in 141 participants was associated with ABCG2 genotype (odds ratio=3.34 (95% CI 1.18-9.50), P=0.024). In our sample of early RA patients who were primarily treated with a combination of DMARDs, common variants in genes that encode NAT2 and ABCG2 were associated respectively with toxicity and response to SSA.

SCN1A variations and response to multiple antiepileptic drugs.

In the current study, we have used the haplotype-tagging single-nucleotide polymorphisms (SNPs) to determine associations between genetic variants in SCN1A and treatment response in 519 Caucasian patients with known response status for epilepsy treated with antiepileptic drugs (AEDs) with sodium channel blocking effects. Nine SNPs within SCN1A were genotyped in this cohort. The only association observed was for rs10188577. A greater proportion of drug-resistant patients were heterozygous compared with drug responsive patients (48.3% vs 35.4%, P=0.014). After correction for potential confounding factors, the association for rs10188577 was only marginally significant (P=0.049). In light of our findings, it seems unlikely that rs10188577 could be a major determinant of response to AEDs. However, looking at the influence of rs10188577 on the expressed quantitative trait association patterns within the immediate vicinity of SCN1A, we found significant associations with neighbouring sodium channel genes, SCN7A and SCN9A (P<0.025), which warrants further studies.

IL7RA polymorphisms and chronic inflammatory arthropathies.

The C allele of a single nucleotide polymorphism (SNP), rs6897932, located in the interleukin-7 receptor alpha chain (IL7RA) was recently found to be associated with multiple sclerosis and Type I diabetes. We analysed 13 SNPs in the IL7RA gene in a combined cohort of patients with chronic inflammatory arthropathies (rheumatoid arthritis and juvenile idiopathic arthritis; 368 patients and 532 unaffected subjects). No significant associations with disease were found with the exception of the non-synonymous SNP rs6897932. This SNP showed modest enrichment of the TT genotype in arthritic patients compared with controls [P = 0.02; OR 1.72 (95% CI 1.08-2.75)]. Our data are suggestive for a role of rs6897932 in predisposition to chronic inflammatory arthropathies.

The MHC2TA-168A/G and +1614G/C polymorphisms and risk for multiple sclerosis or chronic inflammatory arthropathies.

The -168A-G polymorphism has been shown to influence transcription of the MHC2TA gene and has been implicated in several inflammatory/autoimmune disorders. Attempts to reproduce these findings have been inconclusive. We investigated the role of this promoter single nucleotide polymorphism (SNP) in 440 multiple sclerosis (MS), 293 rheumatoid arthritis (RA), 74 juvenile idiopathic arthritis (JIA) patients and 316 healthy controls from Northern Ireland. We also genotyped a non-synonymous SNP in exon 11, +1614G/C. There was no significant difference in the -168G allele frequencies and carriage rates in the separate RA, JIA, or MS collections compared with the control group [odds ratio (OR) = 1.1, 95% confidence intervals (CI) = 0.86-1.44; OR = 1.1, 95% CI = 0.75-1.68; OR = 1.1, 95% CI = 0.84-1.35, respectively]. Assessment of the common phenotype (chronic inflammatory disease; n = 807 vs 316 controls) was negative as well. Carriage of +1614C was protective against JIA (OR = 0.6, 95% CI = 0.3-1.0) and showed a similar trend in RA and MS (OR = 0.7, 95% CI = 0.5-1.0; OR = 0.8, 95% CI = 0.6-1.0, respectively). The common phenotype (chronic inflammatory disease) was also significant (OR = 0.7, 95% CI = 0.6-1.0).

The CTLA4+49A/G and CT60 polymorphisms and chronic inflammatory arthropathies in Northern Ireland.

Rheumatoid and juvenile idiopathic arthritis (RA, JIA) are chronic inflammatory arthropathies with an autoimmune background. The cytotoxic T-lymphocyte antigen-4 (CTLA-4) protein plays a key role in the down-regulation of T cell activation. We analyzed the CTLA4 +49A/G and CT60 polymorphisms in cohorts of Northern Irish RA and JIA patients and healthy control subjects using restriction fragment length polymorphism methods. The +49 A allele was increased in RA (61.2%; P=0.02; OR=1.28; 95% C.I.=1.04-1.58) and JIA (61.8%; P=0.14) patients compared to the control population (55.3%). No significant association was observed for the CT60 polymorphism. Haplotype analysis revealed a significantly different distribution of +49 A/G-CT60 haplotypes in RA and JIA patients compared to controls (P value<0.00001 and 0.030 for comparison of RA and JIA patients with controls, respectively). Our results suggest that the CTLA-4 gene is involved in predisposition to inflammatory arthropathies in the Northern Irish population.

Phase II trial of liposomal daunorubicin in malignant pleural mesothelioma.

BACKGROUND: To assess the response rate, toxicity and survival in patients with malignant pleural mesothelioma treated with liposomal daunorubicin. The study design allowed for dose escalation pending toxicity. PATIENTS AND METHODS: Liposomal daunorubicin (DaunoXome, Nexstar, USA) 120 mg/m2 was administered every 21 days to a maximum of 6 cycles. Patients had to have histologically-proven malignant pleural mesothelioma. Patients were all chemotherapy-naïve with ECOG performance status 0-2. RESULTS: Fourteen patients were enrolled. There were no objective or symptomatic responses though nine patients (64%) had stable disease on therapy. Myelosuppression was the major toxicity with 9 of 11 patients evaluable for toxicity experiencing grade 3 or 4 neutropenia. Other toxicities seen in at least 30% of patients included grade 3 infection and grade 2 nausea and vomiting. The median overall survival by intention-to-treat analysis was 6.1 months from the time of first treatment. The median duration of stable disease from time of first treatment for patients not progressing on therapy was 5.1 months. CONCLUSIONS: Liposomal daunorubicin 120 mg/m2 has no useful clinical activity in patients with malignant pleural mesothelioma. Toxicity was substantial with most patients experiencing at least one episode of grade 3 or 4 neutropenia. Liposomal daunorubicin cannot be recommended for patients with malignant pleural mesothelioma.

Prevalence and characteristics of breakthrough pain in patients with non-malignant terminal disease admitted to a hospice.

A prospective survey was undertaken to determine the prevalence and characteristics of breakthrough pain in patients with non-malignant terminal disease admitted to a hospice. Of the 78 admissions surveyed, 10 patients were confused or too unwell to take part and 25 were pain-free. The remaining 43 reported 86 pains (range 1-6 per patient); of these patients, 27 (63%) had breakthrough pain and identified 52 pains (range 1-5 per patient). Breakthrough pain was classified as somatic (46%) visceral (14%), neuropathic (25%) or mixed aetiology (15%); 60% of pains were severe or excruciating. The mean number of daily breakthrough pain episodes was five (range 1-13), 54% of which occurred suddenly. Most pains (56%) were unpredictable; 75% lasted less than 30 min. These findings suggest that breakthrough pain is common in patients with non-malignant terminal disease; it is frequent, short lasting and often unpredictable, thus making treatment difficult.

Drugs and syringe drivers: a survey of adult specialist palliative care practice in the United Kingdom and Eire.

Subcutaneous delivery of drugs using a syringe driver is common practice within specialist palliative care units. There is, however, little documented information regarding clinical practice. A survey performed in 1992 reported that at least 28 drugs were used in combination with others in a single syringe driver. The aim of the present study was to reassess practice in this field and to enquire more specifically about newer drugs. Postal questionnaires were sent to all adult specialist palliative care in-patient units in the UK and Eire (n = 208). One hundred and sixty-five units (79%) responded. The most common syringe driver in use was the Graseby 26 (61% of responding units). Most units delivered the contents of the syringe over 24 h, and water was usually used as the diluent in 90% of cases. The maximum number of drugs that respondents were prepared to mix in a single syringe was usually three (51%) or four (35%). In the UK, all units used diamorphine in doses from 2.5 mg/24 h upwards. All respondents also used haloperidol, in doses from 0.5 to 60 mg/24 h. A total of 28 different drugs were used in syringe drivers. The most common combinations were diamorphine and midazolam (37%), diamorphine and levomepromazine (35%), diamorphine and haloperidol (33%), and diamorphine and cyclizine (31%). In conclusion, there is much in common with regard to the way in which drugs are delivered in syringe drivers. However, a wide variety of drugs and drug combinations are still in use.

Prevalence and characteristics of breakthrough pain in cancer patients admitted to a hospice.

A prospective survey was undertaken to determine the prevalence and characteristics of breakthrough pain in cancer patients admitted to a hospice. Of 414 consecutive admissions, 33 patients were confused or too unwell to take part and 136 were pain-free. The remaining 245 reported 404 pains (range 1-5 per patient); of these patients, 218 (89%) had breakthrough pain and identified 361 pains (range 1-5 per patient). Breakthrough pain was classified as somatic (46%) visceral (30%), neuropathic (10%) or mixed etiology (16%). Thirty-eight percent of pains were severe or excruciating. The average number of daily breakthrough pain episodes was 4 [corrected] (range 1-14); 49% occurred suddenly. Most (59%) were unpredictable, and 72% lasted less than 30 minutes. Seventy-five percent of patients were dissatisfied with their pain control. Breakthrough pain is common among patients admitted to our hospice. It is frequent, short lasting, often unpredictable and not necessarily related to chronic pain making treatment difficult.

Should high-dose chemotherapy be used to consolidate second or third line treatment in relapsing germ cell tumours?

Thirty consecutive patients with relapsing germ cell tumours (GCT) were treated with induction chemotherapy and high-dose chemotherapy consolidation (HDCT). Overall, 47% were progressionfree and 53% were alive with a median follow up of 40 months. Initially, HDCT was given as consolidation of third line VIP (etoposide/ifosfamide and cisplatin), following failure of a weekly cisplatin regimen. During 1995, paclitaxel was introduced into second line therapy with cisplatin and ifosfamide (TIP), with immediate consolidation using HDCT. At the same time the carboplatin dosing calculation was changed and an area under the curve (AUC) formula rather than by mg/m2 was used to calculate this. The main determinant of post-treatment renal dysfunction was pretreatment renal function rather than the AUC dose of carboplatin. Only a raised LDH prior to induction or absolute refractory disease in response to induction chemotherapy predicted poor survival following HDCT. In patients relapsing following HDCT, the outcome was poor with many patients relapsing in the central nervous system and other new sites of disease. Further responses were seen to chemotherapy or radiotherapy but these were not sustained. The failure to improve results when HDCT was used as second line rather than third line chemotherapy consolidation was disappointing and adds to further uncertainty of the role of this approach as far as timing and the ideal preparative regimen are concerned.

Syringoacanthoma: an acrosyringeal tumour.

Syringoacanthoma is a rare benign appendage tumour derived from the intraepidermal portion of the acrosyringium. We report its occurrence in 3 women. In each case the tumour clinically most resembled a seborrhoeic keratosis. Its importance histopathologically lies in the need to differentiate it from conditions such as malignant melanoma, squamous cell carcinoma, intraepidermal carcinoma, Paget's disease and metastasis, which may all show intraepidermal spread.

Fluorescent lights, ultraviolet lamps, and risk of cutaneous melanoma.

Exposure to solar radiation is increasingly being associated with a risk of cutaneous melanoma, and some risk has also been attributed to exposure to fluorescent lights. The risk of cutaneous melanoma associated with exposure to some sources of artificial ultraviolet radiation was examined in a case-control study in a Scottish population with fairly low exposure to natural ultraviolet radiation. The risk was not significantly or consistently raised for exposure to fluorescent lights at home or at work. The use of ultraviolet lamps and sunbeds, however, was associated with a significantly increased risk (relative risk = 2.9; 95% confidence interval 1.3 to 6.4), and the risk was significantly related to duration of use. The risk was particularly raised among people who have first used [corrected] ultraviolet beds or lamps more than [corrected] five years before presentation (relative risk = 9.1; 95% confidence intervals 2.0-40.6), in whom it was significantly related to cumulative hours of exposure. The risks associated with exposure to ultraviolet lamps and sunbeds remained significant after adjustment for other risk factors for melanoma.