Myositis with prominent B cell aggregates may meet classification criteria for sporadic inclusion body myositis.

The objective of this study was to report the clinical, serological and pathological features of patients with autoimmune myositis other than dermatomyositis, who displayed both muscle weakness on physical examination and prominent B cell aggregates on muscle pathology, defined as ≥ 30 CD20+ cells/aggregate. Specifically, the presence of a brachio-cervical inflammatory myopathies or a sporadic inclusion body myositis (sIBM) phenotype was recorded. Over a three-year period, eight patients were identified from two university neuropathology referral centers. Seven of 8 (88%) patients had an associated connective tissue disease (CTD): rheumatoid arthritis (n=3), systemic sclerosis (n=2), Sjögren's syndrome (n=1) and systemic lupus erythematosus (n=1), while one patient died on initial presentation without a complete serological and cancer investigation. A brachio-cervical phenotype, i.e. neck weakness, proximal weakness more than distal and shoulder abduction weakness greater than hip flexors, was seen in two patients (25%), while one patient had both proximal and diaphragmatic weakness. In contrast, an IBM-like clinical phenotype was seen in the last five patients (63%), who either had finger flexor weakness and/or quadriceps weakness ≤ 4 on the manual muscle testing MRC-5 scale. Although these 5 patients met at least one set of classification criteria for sIBM, an integrated clinico-sero-pathological approach argued against a diagnosis of sIBM. In summary, in a weak patient with myositis plus an associated CTD and lymphoid aggregates at muscle pathology, B cell predominant aggregates may represent a morphological biomarker against a diagnosis of sIBM.

Colour Doppler ultrasound and the giant cell arteritis probability score for the diagnosis of giant cell arteritis: a Canadian single-centre experience.

OBJECTIVES: The aim was to compare the accuracy of colour Doppler ultrasonography (CDUS) and temporal artery biopsy (TAB) to establish the final diagnosis of GCA and to determine how the GCA probability score (GCAPS) performs as a risk stratification tool. METHODS: Descriptive statistics were performed on a retrospective cohort of patients referred to our vasculitis referral centre between 1 July 2017 and 1 October 2020 for suspected GCA. CDUS, TAB, centre-specific TAB (vasculitis centre vs referring hospitals) and GCAPS were compared against the final diagnosis of GCA as determined by a GCA expert; CDUS was also compared with TAB results. RESULTS: Data from 198 patients were included: 60 patients with GCA and 138 patients without GCA. Sixty-two patients had a TAB. Using the final diagnosis by a GCA expert as a reference, the sensitivity, specificity, positive predictive value and negative predictive value were 93.3%, 98.5%, 96.6% and 97.1% for CDUS and 69.2%, 100%, 100% and 81.8% for TAB, respectively. The false-negative rate was 6.7% for CDUS and 30.8% for TAB. False-negative TAB mostly occurred when performed in referring hospitals (57.1%) as opposed to our vasculitis centre (21.1%). With a cut-off at 9.5 points, sensitivity for GCAPS was 98.3% and specificity 74.3%. CONCLUSION: CDUS of the temporal and axillary arteries showed a high sensitivity and specificity and helped to diagnose GCA in patients with negative TAB. We validated that GCAPS is a useful clinical tool, with a score of <9.5 making the diagnosis of GCA improbable.

Optimizing Thiopurine Therapy with a Xanthine Oxidase Inhibitor in Patients with Systemic Autoimmune Diseases: A Single-Centre Experience.

BACKGROUND: Thiopurines are a mainstay of therapy for autoimmune diseases. However, up to 20% to 30% of patients experience overproduction of the methylated metabolites, known as 6-MMP, to the detriment of the active metabolite, 6-thioguanine nucleotide (6-TGN). These patients, commonly referred to as "shunters", are predisposed to thiopurine resistance and hepatotoxicity. In patients with inflammatory bowel diseases, the combination of thiopurine with a xanthine oxidase inhibitor (XOI) is used to reverse this skewed metabolism and to prevent treatment failure or hepatotoxicity. Data on the use of this strategy for patients with other diseases are limited. OBJECTIVES: To investigate and describe the use of thiopurine-XOI combination therapy in shunters with systemic autoimmune diseases. METHODS: Shunters treated in the study hospital between January 1, 2005, and December 31, 2015, were identified using the hospital's laboratory database, and clinical data were collected retrospectively. For each patient with optimization of thiopurine therapy, clinical and laboratory data were assessed over a 6-month period. RESULTS: Thirty-four patients were identified as shunters; for 14 of these patients, thiopurine therapy was optimized with an XOI. In these 14 patients, the median dose of azathioprine was reduced from 1.95 to 0.78 mg/kg with combination therapy. In addition, median 6-TGN level increased from 135 to 385 pmol/8 × 108 erythrocytes (p = 0.001); furthermore, 6-TGN levels rose to above 235 pmol/8 ×108 erythrocytes for 11 of the 14 patients. Conversely, the median 6-MMP level decreased from 6267 to 271 pmol/8 × 108 erythrocytes (p = 0.001). Except for a 12% increase in mean corpuscular volume, no clinically significant changes in blood count were recorded. Notable infections were reported in 3 patients, and 1 patient had to discontinue treatment because of cytopenia. After 6 months, median prednisone daily dose was reduced by 74%, from 16.7 mg to 4.4 mg (p = 0.005), and 4 patients had been weaned off corticosteroids. Of the 14 patients, 11 (79%) were in full remission, and 2 (14%) were in partial remission. CONCLUSION: Optimizing thiopurine therapy with an XOI may be a safe and effective strategy for patients with systemic autoimmune diseases.

CONTEXTE: Les thiopurines sont des piliers de l'intervention thérapeutique contre les maladies auto-immunes. Cependant, 20 % à 30 % des patients surproduisent des métabolites méthylés (connus sous le nom 6-MMP), au détriment du métabolite actif, le nucléotide 6-thioguanine (6-TGN). Ces patients, communément appelés « courts-circuiteurs ¼ sont prédisposés à résister à la thiopurine et à l'hépatotoxicité. Pour les patients ayant des maladies inflammatoires intestinales, on utilise la combinaison de thiopurine avec une xanthine oxydase inhibitrice (XOI) afin d'inverser ce métabolisme anormal et prévenir l'échec du traitement ou l'hépatotoxicité. Les données concernant l'adoption de cette stratégie pour les patients atteints d'autres maladies sont limitées. OBJECTIFS: Étudier et décrire l'utilisation de la thérapie combinée de thiopurine et de XOI pour les « courts-circuiteurs ¼ ayant des maladies auto-immunes systémiques. MÉTHODES: Les « courts-circuiteurs ¼ traités dans l'hôpital où s'est déroulée l'étude entre le 1er janvier 2005 et le 31 décembre 2015 ont été identifiés à l'aide de la base de données du laboratoire de l'hôpital et les données cliniques ont été recueillies de manière rétrospective. L'évaluation des données cliniques et de laboratoire de chaque patient bénéficiant d'une optimisation de la thérapie par la thiopurine a porté sur six mois de traitement. RÉSULTATS: Trente-quatre patients ont été identifiés comme « courts-circuiteurs ¼ et 14 d'entre eux ont bénéficié d'une optimisation de la thérapie par la thiopurine à l'aide d'une XOI. Ces derniers ont subi une thérapie de combinaison qui a fait passer la dose moyenne d'azathioprine de 1,95 à 0,78 mg/kg. De plus, le niveau moyen de 6-TGN est passé de 135 à 385 pmol/8 × 108 érythrocytes (p = 0,001). En outre, 11 des 14 patients ont vu le niveau de 6-TGN passer à plus de 235 pmol/8 ×108 érythrocytes. Inversement, le niveau moyen de 6-MMP est passé de 6267 à 271 pmol/8 × 108 érythrocytes (p = 0,001). À l'exception d'une augmentation de 12 % du volume corpusculaire moyen, aucun changement clinique important dans la numération globulaire n'a été noté. Trois patients ont développé des infections notables et l'un d'eux a dû arrêter le traitement à cause d'une cytopénie. Après six mois, la dose moyenne quotidienne de prednisone a été réduite de 74 %, pour passer de 16,7 mg à 4,4 mg (p = 0,005), et quatre patients ont été sevrés des corticostéroïdes. Sur les 14 patients, 11 (79 %) ont été déclarés en rémission totale et 2 (14 %) en rémission partielle. CONCLUSION: L'optimisation de la thérapie par la thiopurine associée à une XOI pourrait être sécuritaire et constituer une stratégie efficace pour les patients ayant une maladie auto-immune systémique.

Recognising the spectrum of scleromyositis: HEp-2 ANA patterns allow identification of a novel clinical subset with anti-SMN autoantibodies.

OBJECTIVE: To describe systemic sclerosis (SSc) with myopathy in patients without classic SSc-specific and SSc-overlap autoantibodies (aAbs), referred to as seronegative scleromyositis. METHODS: Twenty patients with seronegative scleromyositis diagnosed by expert opinion were analysed retrospectively for SSc features at myositis diagnosis and follow-up, and stratified based on HEp-2 nuclear patterns by indirect immunofluorescence (IIF) according to International Consensus of Autoantibody Patterns. Specificities were analysed by protein A-assisted immunoprecipitation. Myopathy was considered an organ involvement of SSc. RESULTS: SSc sine scleroderma was a frequent presentation (45%) at myositis diagnosis. Myositis was the most common first non-Raynaud manifestation of SSc (55%). Lower oesophagal dysmotility was present in 10 of 11 (91%) investigated patients. At follow-up, 80% of the patients met the American College of Rheumatology/EULAR SSc classification criteria. Two-thirds of patients had a positive HEp-2 IIF nuclear pattern (all with titers ≥1/320), defining three novel scleromyositis subsets. First, antinuclear antibody (ANA)-negative scleromyositis was associated with interstitial lung disease (ILD) and renal crisis. Second, a speckled pattern uncovered multiple rare SSc-specific aAbs. Third, the nuclear dots pattern was associated with aAbs to survival of motor neuron (SMN) complex and a novel scleromyositis subset characteriszed by calcinosis but infrequent ILD and renal crisis. CONCLUSIONS: SSc skin involvement is often absent in early seronegative scleromyositis. ANA positivity, Raynaud phenomenon, SSc-type capillaroscopy and/or lower oesophagal dysmotility may be clues for scleromyositis. Using HEp-2 IIF patterns, three novel clinicoserological subsets of scleromyositis emerged, notably (1) ANA-negative, (2) ANA-positive with a speckled pattern and (3) ANA-positive with nuclear dots and anti-SMN aAbs.

Statin-induced anti-HMGCR myopathy: successful therapeutic strategies for corticosteroid-free remission in 55 patients.

OBJECTIVE: To describe successful therapeutic strategies in statin-induced anti-HMGCR myopathy. METHODS: Retrospective data from a cohort of 55 patients with statin-induced anti-HMGCR myopathy, sequentially stratified by the presence of proximal weakness, early remission, and corticosteroid and IVIG use at treatment induction, were analyzed for optimal successful induction and maintenance of remission strategies. RESULTS: A total of 14 patients achieved remission with a corticosteroid-free induction strategy (25%). In 41 patients treated with corticosteroids, only 4 patients (10%) failed an initial triple steroid/IVIG/steroid-sparing immunosuppressant (SSI) induction strategy. Delay in treatment initiation was independently associated with lower odds of successful maintenance with immunosuppressant monotherapy (OR 0.92, 95% CI 0.85 to 0.97, P = 0.015). While 22 patients (40%) presented with normal strength, only 9 had normal strength at initiation of treatment. CONCLUSION: While corticosteroid-free treatment of anti-HMGCR myopathy is now a safe option in selected cases, initial triple steroid/IVIG/SSI was very efficacious in induction. Delays in treatment initiation and, as a corollary, delays in achieving remission decrease the odds of achieving successful maintenance with an SSI alone. Avoiding such delays, most notably in patients with normal strength, may reset the natural history of anti-HMGCR myopathy from a refractory entity to a treatable disease.

Metabolite monitoring to guide thiopurine therapy in systemic autoimmune diseases.

6-Thioguanine nucleotide (6-TGN) is the active metabolite of thiopurine drugs azathioprine and 6-mercaptopurine. 6-Methylmercaptopurine (6-MMP) is an inactive and potentially hepatotoxic metabolite. A subgroup of patients (shunters) preferentially produce 6-MMP instead of 6-TGN, therefore displaying thiopurine resistance and risk for hepatotoxicity. Outside inflammatory bowel disease literature, few data exist regarding individualized thiopurine therapy based on metabolite monitoring. This study sought to describe metabolite monitoring in patients receiving weight-based thiopurine for systemic autoimmune diseases. Patients were enrolled using a laboratory database, and data were retrospectively collected. The correlation between the highest thiopurine dose (mg/kg) and the 6-TGN concentration (pmol/8 × 108 erythrocytes) was estimated with Pearson's correlation coefficient. Seventy-one patients with various systemic autoimmune conditions were enrolled. The correlation between the thiopurine dose and the 6-TGN level was weak for the overall patient sample (r = 0.201, p = 0.092) and for the subgroup of non-shunters (r = 0.278, p = 0.053). Subjects with 6-MMP levels >5700 pmol/8 × 108 erythrocytes had more hepatic cytolysis compared to subjects with 6-MMP <5700, OR = 4.36 (CI 95% 1.18-16.13, p = 0.027). Twenty-two patients (31%) were identified as shunters. Six shunters developed hepatotoxicity, five of which had 6-MMP concentration >5700. Eleven non-shunters had hepatotoxicity, one of which had 6-MMP >5700. Thiopurine metabolite monitoring shows wide variability in 6-TGN levels among patients treated with weight-based thiopurine for systemic autoimmune diseases. Thirty-one percent of the patients in our series fulfilled the shunter definition. Thiopurine metabolite monitoring and dose adjustment to improve maintenance of remission and avoid hepatotoxicity should be studied prospectively.

A rare case of a carcinoid myocardial mass.

Right-sided valvular disease is characteristic of the carcinoid syndrome. In contrast, myocardial involvement is unusual. We present a case of an asymptomatic patient who had a myocardial carcinoid tumor discovered during surgery for coronary artery disease. The clinical presentation, diagnostic tests and modalities, and outcomes after surgery are discussed in this case report.

Febuxostat as a novel option to optimize thiopurines' metabolism in patients with inadequate metabolite levels.

OBJECTIVE: To report the use of febuxostat in order to potentiate thiopurines' metabolism in a patient on azathioprine (AZA) therapy with low metabolite 6-thioguanine nucleotides (6-TGN) levels and elevated metabolite 6-methylmercaptopurine (6-MMP) levels. CASE SUMMARY: A 44-year-old woman with a history of anti-signal recognition particle necrotizing myopathy was treated with AZA-allopurinol combination therapy. When she developed an atypical drug-induced hypersensitivity syndrome, allopurinol was replaced by the new xanthine oxidase (XO) inhibitor febuxostat, at a daily dose of 40 mg. Febuxostat-AZA combination was successful with 6-TGN reaching therapeutic levels while 6-MMP levels remained low. After 5 months, she developed similar manifestations that she had presented on AZA-allopurinol combination. Febuxostat and AZA were then stopped. DISCUSSION: AZA and 6-MP are both inactive pro-drugs that undergo a complex metabolic transformation leading to active 6-TGN and potentially hepatotoxic 6-MMP. Some patients with unfavorable thiopurine metabolism might benefit from addition of XO inhibitor allopurinol in order to potentiate 6-TGN and reduce 6-MMP levels. It is likely that febuxostat, via its XO inhibition, would exhibit the same effect on thiopurines' metabolism. CONCLUSION: It has been shown that low dose of febuxostat was able to prevent hypermethylation and to potentiate 6-TGN levels in an AZA-treated patient. Thus, febuxostat could be useful in optimizing thiopurines' metabolism, but more data are needed before this practice can be recommended. The mechanisms by which febuxostat optimizes thiopurines' metabolism remain to be confirmed. Also, the optimal dose of febuxostat for this use remains to be determined.