JAK2 Unmutated Polycythaemia-Real-World Data of 10 Years from a Tertiary Reference Hospital.

(1) Background: Polycythaemia is defined by an increase in haemoglobin (Hb) concentration, haematocrit (Hct) or red blood cell (RBC) count above the reference range adjusted to age, sex and living altitude. JAK2 unmutated polycythaemia is frequent but under-investigated in original publications. In this retrospective cohort study, we investigated the clinical and laboratory data, underlying causes, management and outcomes of JAK2 unmutated polycythaemia patients. (2) Methods: The hospital database was searched to identify JAK2 unmutated patients fulfilling WHO 2016 Hb/Hct criteria for PV (Hb >16.5 g/dL in men and >16 g/dL in women, or Hct > 49% in men and >48% in women, or RBC mass > 25% above mean normal predicted value) between 2008 and 2019. Clinical and laboratory data were collected and analysed. (3) Results: From 727,731 screened patients, 294 (0.04%) were included, the median follow-up time was 47 months. Epo and P50 showed no clear pattern in differentiating causes of polycythaemia. In 30%, the cause remained idiopathic, despite extensive work-up. Sleep apnoea was the primary cause, also in patients under 30. Around 20% had received treatment at any time, half of whom had ongoing treatment at the end of follow-up. During follow-up, 17.2% developed a thromboembolic event, of which 8.5% were venous and 8.8% arterial. The mortality was around 3%. (4) Conclusions: Testing for Epo and P50 did not significantly facilitate identification of underlying causes. The frequency of sleep apnoea stresses the need to investigate this condition. Idiopathic forms are common. A diagnostic flowchart based on our data is proposed here. NGS testing should be considered in young patients with persisting polycythaemia, irrespective of Epo and P50 levels.

Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis in Association with Commonly Prescribed Drugs in Outpatient Care Other than Anti-Epileptic Drugs and Antibiotics: A Population-Based Case-Control Study.

INTRODUCTION: Stevens-Johnson syndrome and toxic epidermal necrolysis have been associated with the use of various drugs, but evidence is scarce. We studied the association between new use of outpatient drugs other than anti-epileptic drugs and antibiotics and Stevens-Johnson syndrome and toxic epidermal necrolysis. METHODS: We conducted a matched (1:4) case-control analysis in 480 previously validated Stevens-Johnson syndrome/toxic epidermal necrolysis cases (1995-2013). We calculated odds ratios with 95% confidence intervals for Stevens-Johnson syndrome/toxic epidermal necrolysis in new users of drugs compared to non-users. For cases of Stevens-Johnson syndrome/toxic epidermal necrolysis diagnosed ≤ 84 days after the first use of a drug, we assessed causality between drug exposure and Stevens-Johnson syndrome/toxic epidermal necrolysis using ALDEN (algorithm of drug causality in epidermal necrolysis). We calculated absolute risks by dividing the number of Stevens-Johnson syndrome/toxic epidermal necrolysis cases ≤ 84 days after new drug exposure by the total number of new users of the drug. RESULTS: There was an association between Stevens-Johnson syndrome/toxic epidermal necrolysis and the use of allopurinol (odds ratio 24.51, 95% confidence interval 2.94-204.04) and cyclooxygenase-2 inhibitors (odds ratio 24.19, 95% confidence interval 2.91-200.92). Proton pump inhibitors, fluoxetine, mirtazapine, and 5-aminosalicylates (sulfasalazine, mesalamine) were also associated with an increased risk of Stevens-Johnson syndrome/toxic epidermal necrolysis, though with lower odds ratios. ALDEN score application suggests a likely causality for these associations. Absolute risks of Stevens-Johnson syndrome/toxic epidermal necrolysis were 6.0/100,000 new users for allopurinol, and 1.9-4.3/100,000 new users for cyclooxygenase-2 inhibitors and 5-aminosalicylates, and 0.2-1.6/100,000 new users for proton pump inhibitors, fluoxetine, and mirtazapine. We found no association between Stevens-Johnson syndrome/toxic epidermal necrolysis and oxicams, benzodiazepines, citalopram, sertraline, paroxetine, venlafaxine, and phosphodiesterase-5 inhibitors despite > 100,000 new users. CONCLUSIONS: In this observational study, we observed likely causal associations between Stevens-Johnson syndrome/toxic epidermal necrolysis and use of allopurinol, cyclooxygenase-2 inhibitors, and 5-aminosalicylates, and potential associations for proton pump inhibitors, fluoxetine, and mirtazapine.

Risk of Incident Osteoarthritis of the Hand in Statin Initiators: A Sequential Cohort Study.

OBJECTIVE: To investigate the association between statin therapy initiation and incident hand osteoarthritis (OA). METHODS: We performed a propensity score-matched cohort study using data from the UK-based Clinical Practice Research Datalink. Statin initiators had ≥1 statin prescription between 1996 and 2015 and were matched 1:1 on their propensity score to noninitiators within 10 sequential 2-year cohort entry blocks. After a 180-day run-in period, patients were followed in an as-treated approach until a recorded diagnosis of hand OA or until censoring (change in exposure status, development of an exclusion criterion, or maximum follow-up of 5.5 years). We applied Cox proportional hazard regression to calculate hazard ratios (HRs) with 95% confidence intervals (95% CIs) overall and in subgroups of sex, age, statin dose, statin agent, preexisting dyslipidemia, and treatment duration. To compare results, we ran all analyses with negative and positive control outcomes and assessed generalized OA as a secondary outcome. We further performed the overall analysis with an active comparator (topical glaucoma therapy initiators). RESULTS: Among 233,608 statin initiators and the same number of noninitiators, we observed an overall HR for hand OA of 0.98 (95% CI 0.88-1.09). The observed null result remained unchanged in all subgroups. Results were highly similar for generalized OA and negative control outcomes. In addition, the active comparator analysis showed a null result with an HR for hand OA of 0.85 (95% CI 0.56-1.29). Previously known associations with positive control outcomes were observed. CONCLUSION: There was no association between statin initiation and incident hand OA in this study.

The risk of Stevens-Johnson syndrome and toxic epidermal necrolysis in new users of antiepileptic drugs.

OBJECTIVE: Older antiepileptic drugs (AEDs) are known to cause Stevens-Johnson syndrome and toxic epidermal necrolysis (SJS/TEN). However, evidence for newer AED is sparse. We quantified risks of SJS/TEN in association with use of all AEDs in the United Kingdom. METHODS: In a matched case-control study of 480 previously validated SJS/TEN cases (1995-2013) we used conditional logistic regression to calculate odds ratios (ORs) with 95% confidence intervals (CIs), and calculated absolute risks of SJS/TEN within separate cohorts of new users of 28 AEDs. We assessed causality between drugs and SJS/TEN in each exposed case, using an adapted version of the algorithm of drug causality for epidermal necrolysis (ALDEN) score. RESULTS: We observed a strong association between SJS/TEN and new use of carbamazepine (OR 92.57, 95% CI 19.89-∞), phenytoin (OR 49.96, 95% CI 10.13-∞), and lamotrigine (OR 26.90, 95% CI 4.88-∞), where causality, according to the ALDEN score, was very probable or probable for most exposed cases. Absolute risks for SJS/TEN were highest for phenytoin (45.86 cases/100,000 exposed), lamotrigine (44.17 cases/100,000 exposed), and carbamazepine (20.38 cases/100,000 exposed). Despite increased ORs for valproate (40,941 exposed), gabapentin (116,037 exposed), pregabalin (59,967 exposed), and clobazam (4,300 exposed), ALDEN suggested no causal association. There were no observed cases of SJS/TEN among new users of levetiracetam (n = 96,77), clonazepam (n = 18,075), or topiramate (n = 11,307). SIGNIFICANCE: The results of our study are consistent with those of previous studies of SJS/TEN, which found increased risks of SJS/TEN in new use of carbamazepine, phenytoin, and lamotrigine. Despite frequent use, no ALDEN-score confirmed cases were observed in new users of valproate, gabapentin, pregabalin, levetiracetam, topiramate, or clonazepam.

The Epidemiology of Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis in the UK.

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare but life-threatening mucocutaneous diseases. SJS/TEN mostly manifest as a reaction to new drug use, but little is known about their incidence and epidemiology. We conducted a large observational study on the epidemiology of SJS/TEN using data from the UK-based Clinical Practice Research Datalink. Among 551 validated SJS/TEN patients, we calculated an incidence rate of 5.76 SJS/TEN cases per million person-years between 1995 and 2013, which was consistent throughout the study period and was highest in patients aged 1-10 years and 80 years or older. Within a 1:4 matched case-control analysis, black and Asian patients were at a 2-fold risk of SJS/TEN when compared with white patients. Among patients with epilepsy and gout, odds ratios for SJS/TEN were significantly increased only in the presence of recent new drug treatment with antiepileptics or allopurinol, respectively. We observed statistically significant associations between SJS/TEN and pre-existing depression, lupus erythematosus, recent pneumonia, chronic kidney disease, and active cancer, but confounding by drug use needs to be followed up. This large and longitudinal observational study on the epidemiology of SJS/TEN contributes to the understanding of this still underinvestigated severe skin disease in a European and largely white study population.

Validation of Stevens-Johnson syndrome or toxic epidermal necrolysis diagnoses in the Clinical Practice Research Datalink.

PURPOSE: To evaluate the validity of recorded diagnoses of Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) in the Clinical Practice Research Datalink (CPRD). METHODS: We identified patients with a diagnosis of SJS or TEN between 1995 and 2013 in the CPRD. We reviewed information from patient records, free text, and hospital episode statistics (HES) data, and excluded patients with no indication of a secondary care referral. Remaining patients were classified as probable, possible, or unlikely cases of SJS/TEN by two specialised clinicians or based on pre-defined classification criteria. We quantified positive predictive values (PPV) for all SJS/TEN patients and for patients categorised as 'probable/possible' cases of SJS/TEN, based on a representative subsample of 118 patients for whom we had unequivocal information (original discharge letters or HES data). RESULTS: We identified 1324 patients with a diagnosis of SJS/TEN, among whom 638 had a secondary care referral recorded. Of those, 565 were classified as probable or possible cases after expert review. We calculated a PPV of 0.79 (95% CI, 0.71-0.86) for all SJS/TEN patients with a recorded secondary care referral, and a PPV of 0.87 (95% CI, 0.81-0.93) for probable/possible cases. After excluding 14 false positive patients, our study population consisted of 551 SJS/TEN patients. CONCLUSIONS: Diagnoses of SJS/TEN are recorded with moderate diagnostic accuracy in the CPRD, which was substantially improved by additional expert review of all available information. We established a large population-based SJS/TEN study population of high diagnostic validity from the CPRD. Copyright © 2016 John Wiley & Sons, Ltd.