[Recurrent deep vein thrombosis and myeloproliferative syndrom: emergence of JAK2 mutation five years after the initial event]

A Case Report of Large Bilateral Pulmonary Embolism in a Patient With Janus Kinase 2 (JAK2) Positive Mutation

Venous thromboembolism may be the primary presentation in patients with polycythaemia vera (PV) and essential thrombocythemia. Most patients get diagnosed with polycythaemia vera after presenting with venous or arterial thromboembolism in the first place. Most patients tend to develop thrombosis just before or at the time of diagnosis, and this risk decreases over time. Patients aged >60 years with a history of previous thrombosis, elevated haematocrit, and leukocytosis are most at risk of thrombosis. We report a case of a 74-year-old patient presenting with shortness of breath for three days. A computerized tomography pulmonary angiogram showed bilateral pulmonary emboli with right heart strain. He underwent emergency EkoSonic™ endovascular system-directed thrombolysis (EKOS™, Boston Scientific, Marlborough, MA). The patient tested positive for the Janus kinase 2 gene mutation (JAK2), met two major and one minor criterion for PV, and was discharged home on oral anticoagulation. The Janus kinase 2 (JAK2V617F) mutation is quite common in patients with polycythaemia vera, thrombocythemia, and myelofibrosis, and these patients are at risk of both arterial and venous thrombosis, hence they require long-term follow-up.

JAK3-STAT pathway blocking benefits in experimental lupus nephritis

Background

Lupus nephritis (LN) is a complex chronic autoimmune disease of unknown etiology characterized by loss of tolerance against several self-antigens. Cytokines are known to be central players in LN pathogenesis. The Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway is one important pathway that mediates signal transduction of several cytokines. In this study, we examined the pathogenic role of this pathway and how CP-690,550 treatment influences LN outcome.

Methods

Six-month-old NZB/NZWF1 mice were divided into two different treatment groups: (1) control animals given vehicle treatment, cyclophosphamide, and mycophenolate mofetil treatment as positive controls of the therapy and (2) mice treated with CP-690,550, a JAK3 inhibitor. Mice were treated for 12 weeks. We evaluated renal function, anti-double-stranded DNA (anti-dsDNA) antibody, renal histology changes, kidney complement and immunoglobulin G (IgG) deposits, T-cell and macrophage infiltration, kidney inflammatory gene expression, and circulating cytokine changes.

Results

CP-690,550 treatment significantly reduced proteinuria and improved renal function and histological lesions of the kidney. Compared with vehicle-treated animals, those undergoing CP-690,550 treatment showed significantly diminished anti-dsDNA antibody and complement component C3 and IgG deposition in glomeruli. We also observed a significant reduction of T-cell and macrophage infiltration. Kidney gene expression revealed a reduction in inflammatory cytokines and complement and related macrophage-attracting genes. Circulating inflammatory cytokines were also reduced with treatment.

Conclusions

On the basis of our results, we conclude that the JAK-STAT pathway is implicated in the progression of renal inflammation in NZB/WF1 mice and that targeting JAK3 with CP-690,550 is effective in slowing down the course of experimental LN. Thus, CP-690,550 could become a new therapeutic tool in LN and other autoimmune diseases.

[Splanchnic venous thrombosis: A monocentric study of 31 cases]

INTRODUCTION

Splanchnic vein thrombosis (SVT) denotes thrombosis of the hepatic venous system and of the extrahepatic portal system. They are often the manifestation of one or more underlying prothrombotic states and can sometimes present problems of therapeutic care.

METHODS

We report a monocentric study of 31 cases of SVT observed in an internal medicine department between January 2006 and June 2012. Epidemiological, clinical, laboratory, therapeutic and outcome data were analyzed.

RESULTS

There was a slight female predominance (sex-ratio: 1.2). Median patient age at diagnosis was 37 years. Most cases of SVT were chronic (61.2%). Abdominal pain was the predominant symptom in acute cases while the predominant signs in chronic forms were signs of portal hypertension. Extrasplanchnic thrombosis was noted in seven patients (22.5%). Behçet's disease was the most common etiology (32%). The treatment was based on anticoagulants and corticosteroids and immunosuppressants when an inflammatory etiology was found. The average follow-up was 17 months. There were five deaths (16%).

CONCLUSION

SVT often reflects the existence of a disease and/or an underlying prothrombotic state that should be identified to adapt the treatment and to avoid fatal complications.