Pulmonary arterial hypertension in interferonophaties: a case report and a review of the literature

Case Report: In situ pulmonary artery thrombosis in a 12-year-old girl classified as systemic lupus erythematosus

In situ pulmonary artery thrombosis (ISPAT) is a relatively rare but potentially life-threatening complication of systemic lupus erythematosus (SLE) in children. We report the case of a 12-year-old girl who presented with fever, chest pain, and dyspnea. Immune thrombocytopenia was identified due to purpura and menorrhagia 3 months before presentation with a lowest platelet count of 12 × 109/L. The sudden onset of fever, chest pain, and dyspnea were misdiagnosed as hyperinflammatory responses caused by pneumonia; these symptoms ameliorated with glucocorticoid and antibiotic treatment. The reappearance of symptoms after dose reduction of glucocorticoids and the observation of bloody bronchoalveolar lavage fluid necessitated further evaluation. Pulmonary artery thrombosis/embolism was identified using computed tomography pulmonary angiography and high D-dimer quantitative level of 4,118 μg/L (normal <252 μg/L). Ultrasonography of the deep and superficial veins of both lower limbs and renal veins revealed no thrombosis, suggesting the diagnosis of ISPAT. Further etiological evaluation revealed positive antinuclear antibodies, lupus anticoagulant, and anti-SSA antibodies, confirming SLE. Repeated normal urine analysis indicated that lupus nephritis was unlikely. Further, the negative anticardiolipin and anti-β2 glycoprotein antibodies and temporary positive lupus anticoagulant suggested that antiphospholipid syndrome was unlikely. The patient received anticoagulants, glucocorticoids, hydroxychloroquine, and mycophenolate therapy. Her symptoms gradually improved, and she was discharged. At the 1-month follow-up, the thrombosis had resolved. During the 1-year follow-up, her condition remained well without SLE relapse. Our experience with this case emphasizes searching for SLE in the case of ISPAT and pulmonary hemorrhages. ISPAT can occur in children with SLE and may be caused by hyperinflammatory response during SLE flare.

A very rare cause of pre-capillary pulmonary hypertension: The PAMI syndrome

We report the first known case of PAMI syndrome associated with pulmonary arterial hypertension (PAH) with a positive response to cyclophosphamide and pulmonary vasodilators. The patient's history began at 7 months with severe pancytopenia and fever. As time progressed, migrating arthritis, hepatosplenomegaly, and a growth deficit manifested without a plausible explanation. At the age of 17, worsening dyspnea led to a diagnosis of severe pre-capillary pulmonary hypertension and, after a multidisciplinary evaluation, a dual therapy with both vasoactive and immunosuppressive agents led to rapid clinical improvement. After a decade of stability, stopping sildenafil caused deterioration, reversed upon reintroduction. Thirty years after the onset of signs and symptoms, a genetic test identified the underlying condition known as PAMI syndrome. As PAMI syndrome involves intense systemic inflammation similar to PAH related to systemic lupus erythematosus (SLE), parameters and functional autonomy appropriately responded to early immunosuppressive and vasoactive therapy. PAMI syndrome, a rare autoinflammatory disease, is linked to precapillary pulmonary hypertension but the exact cause and optimal treatment approach are not fully understood, requiring further research for clarification and improved treatment options.

JAK inhibitors in rheumatology

Janus kinase inhibitors (JAKis) are a group of drugs with a different mechanism of action from biologics and are most rapidly uptaken in the rheumatology field. JAK is a protein kinase activated in the cytoplasm by multiple cytokines and hormones involved in inflammatory pathology. The expression of JAK has been observed in various diseases, indicating the utility of JAK inhibitors in a wide variety of immune-mediated inflammatory diseases. Clinical trials are underway for a number of different rheumatic diseases based on the therapeutic efficacy of JAKis, which is comparable to that of biologics. This article will review the current status of JAKis for rheumatic diseases in terms of efficacy and safety and extend to future clinical applications for rare diseases.

Effectiveness and Safety of JAK Inhibitors in Autoinflammatory Diseases: A Systematic Review

Introduction

Autoinflammatory diseases (AID) are rare diseases presenting with episodes of sterile inflammation. These involve multiple organs and can cause both acute organ damage and serious long-term effects, like amyloidosis. Disease-specific anti-inflammatory therapeutic strategies are established for some AID. However, their clinical course frequently includes relapsing, uncontrolled conditions. Therefore, new therapeutic approaches are needed. Janus Kinase inhibitors (JAKi) block key cytokines of AID pathogenesis and can be a potential option.

Methods

A systematic review of the literature in accordance with the PRISMA guidelines was conducted. Three databases (MEDLINE, Embase and Cochrane Central Register of Controlled Trials) were searched for publications regarding the use of JAKi for AID. Data from the included publications was extracted and a narrative synthesis was performed. Criteria for defining treatment response were defined and applied.

Results

We report data from 38 publications with a total of 101 patients describing the effects of JAKi in AID. Data on Type I Interferonopathies, Adult-Onset Still's Disease (AOSD), Systemic Juvenile Idiopathic Arthritis (sJIA), Familial Mediterranean Fever (FMF), and Behçet's Syndrome (BS) was identified. From a total of 52 patients with type I interferonopathies, in seven patients (7/52, 13.5%) a complete response was achieved, most (35/52, 67.3%) showed a partial response and a minority (10/52, 19.2%) showed no treatment response. For AOSD, a complete or a partial response was achieved by eleven (11/26, 42.3%) patients each. Two sJIA patients achieved complete response (2/4, 50%) and in two cases (2/4, 50%) a partial response was reported. Half of FMF patients showed a complete response and the other half had a partial one (3/6, 50.0%). Amongst BS patients most achieved a partial response (8/13, 61.5%). Five patients showed no response to therapy (5/13, 38.5%). Overall, the most frequent AEs were upper respiratory tract infections (17), pneumonia (10), BK virus viremia (10) and viruria (4), herpes zoster infection (5), viral gastroenteritis (2) and other infections (4).

Conclusion

The results from this systematic review show that JAKi can be beneficial in certain AID. The risk of AEs, especially viral infections, should be considered. To accurately assess the risk benefit ratio of JAKi for AID, clinical trials should be conducted.

Early Use of Low-Dose Ruxolitinib: A Promising Strategy for the Treatment of Acute and Chronic GVHD

Janus kinases (JAK) are a family of tyrosine kinases (JAK1, JAK2, JAK3, and TYK2) that transduce cytokine-mediated signals through the JAK–STAT metabolic pathway. These kinases act by regulating the transcription of specific genes capable of inducing biological responses in several immune cell subsets. Inhibition of Janus kinases interferes with the JAK–STAT signaling pathway. Besides being used in the treatment of cancer and inflammatory diseases, in recent years, they have also been used to treat inflammatory conditions, such as graft-versus-host disease (GVHD) and cytokine release syndrome as complications of allogeneic hematopoietic stem cell transplantation and cell therapy. Recently, the FDA approved the use of ruxolitinib, a JAK1/2 inhibitor, in the treatment of acute steroid-refractory GVHD (SR-aGVHD), highlighting the role of JAK inhibition in this immune deregulation. Ruxolitinib was initially used to treat myelofibrosis and true polycythemia in a high-dose treatment and caused hematological toxicity. Since a lower dosage often could not be effective, the use of ruxolitinib was suspended. Subsequently, ruxolitinib was evaluated in adult patients with SR-aGVHD and was found to achieve a rapid and effective response. In addition, its early low-dose use in pediatric patients affected by GVHD has proved effective, safe, and reasonably preventive. The review aims to describe the potential properties of ruxolitinib to identify new therapeutic strategies.

The Third Man: DNA sensing as espionage in pulmonary vascular health and disease

For as long as nucleic acids have been utilized to vertically and horizontally transfer genetic material, living organisms have had to develop methods of recognizing cytosolic DNA as either pathogenic (microbial invasion) or physiologic (mitosis and cellular proliferation). Derangement in key signaling molecules involved in these pathways of DNA sensing result in a family of diseases labeled interferonopathies. An interferonopathy, characterized by constitutive expression of type I interferons, ultimately manifests as severe autoimmune disease at a young age. Afflicted patients present with a constellation of immune-mediated conditions, including primary lung manifestations such as pulmonary fibrosis and pulmonary hypertension. The latter condition is especially interesting in light of the known role that DNA damage plays in a variety of types of inherited and induced pulmonary hypertension, with free DNA detection elevated in the circulation of affected individuals. While little is known regarding the role of cytosolic DNA sensing in development of pulmonary vascular disease, exciting new research in the related fields of immunology and oncology potentially sheds light on future areas of fruitful exploration. As such, the goal of this review is to summarize the state of the field of nucleic acid sensing, extrapolating common shared pathways that parallel our knowledge of pulmonary hypertension, in a molecular and cell-specific manner. Principles of DNA sensing related to known pulmonary injury inducing stimuli are also evaluated, in addition to potential therapeutic targets. Finally, future directions in pulmonary hypertension research and treatments will be briefly discussed.

Lung involvement in monogenic interferonopathies

Monogenic type I interferonopathies are inherited heterogeneous disorders characterised by early onset of systemic and organ specific inflammation, associated with constitutive activation of type I interferons (IFNs). In the last few years, several clinical reports identified the lung as one of the key target organs of IFN-mediated inflammation. The major pulmonary patterns described comprise children's interstitial lung diseases (including diffuse alveolar haemorrhages) and pulmonary arterial hypertension but diagnosis may be challenging. Respiratory symptoms may be either mild or absent at disease onset and variably associated with systemic or organ specific inflammation. In addition, associated extrapulmonary clinical features may precede lung function impairment by years, and patients may display severe/endstage lung involvement, although this may be clinically hidden during the long-term disease course. Conversely, a few cases of atypical severe lung involvement at onset have been reported without clinically manifested extrapulmonary signs. Hence, a multidisciplinary approach involving pulmonologists, paediatricians and rheumatologists should always be considered when a monogenic interferonopathy is suspected. Pulmonologists should also be aware of the main pattern of presentation to allow prompt diagnosis and a targeted therapeutic strategy. In this regard, promising therapeutic strategies rely on Janus kinase-1/2 (JAK-1/2) inhibitors blocking the type I IFN-mediated intracellular cascade.

Biological and Clinical Changes in a Pediatric Series Treated with Off-Label JAK Inhibitors

Off-label use of medications is still a common practice in pediatric rheumatology. JAK inhibitors are authorized in adults in the treatment of rheumatoid arthritis, psoriatic arthritis and ulcerative colitis. Although their use is not authorized yet in children, JAK inhibitors, based on their mechanism of action and on clinical experiences in small series, have been suggested to be useful in the treatment of pediatric interferon-mediated inflammation. Accordingly, an increased interferon score may help to identify those patients who might benefit of JAK inhibitors. We describe the clinical experience with JAK inhibitors in seven children affected with severe inflammatory conditions and we discuss the correlation between clinical features and transcriptomic data. Clinical improvements were recorded in all cases. A reduction of interferon signaling was recorded in three out of seven subjects at last follow-up, irrespectively from clinical improvements. Other signal pathways with significant differences between patients and controls included upregulation of DNA repair pathway and downregulation of extracellular collagen homeostasis. Two patients developed drug-related adverse events, which were considered serious in one case. In conclusion, JAK inhibitors may offer a valuable option for children with severe interferon-mediated inflammatory disorders reducing the interferon score as well as influencing other signal pathways that deserve future studies.