Diffuse Alveolar Hemorrhage in Systemic Lupus Erythematosus: Histopathologic Features and Clinical Correlations

Dysregulation of the cGAS-STING Pathway in Monogenic Autoinflammation and Lupus

One of the oldest mechanisms of immune defense against pathogens is through detection of foreign DNA. Since human DNA is compartmentalized into the nucleus, its presence in the cytosol heralds a potential threat. The cGAS-STING pathway is one of the most important cytosolic DNA sensing pathways and leads to interferon signaling, inflammasome activation, autophagy, and cell death. While STING signaling is protective at physiologic levels, chronic activation of this pathway can instead drive autoinflammation and autoimmunity. Here we discuss several monogenic disorders of the STING pathway that highlight its impact on both innate and adaptive immunity in the progressive loss of tolerance. The potential relevance of STING signaling in systemic lupus erythematosus is then discussed with a focus on future avenues for monitoring and targeting this pathway.

Lupus anticoagulant hypoprothrombinemia syndrome associated with bilateral adrenal haemorrhage in a child: early diagnosis and intervention

BACKGROUND

Lupus anticoagulant-hypoprothrombinemia syndrome (LAHPS) is characterized by bleeding and thrombosis in patients with autoimmune diseases or infections. Paediatric LAHPS exhibits various degrees of bleeding, ranging from mild to severe; however, adrenal haemorrhage due to LAHPS and its long-term clinical course have not been sufficiently described.

CASE PRESENTATION

A 9-year-old boy presented with prolonged abdominal pain and abnormal coagulation screening tests. The laboratory tests showed prolonged activated partial thromboplastin time and subsequently revealed the presence of lupus anticoagulant, anti-nuclear antibodies, and hypoprothrombinemia, leading to diagnosis of LAHPS. An enhanced computed tomogram demonstrated nodular lesions in the adrenal glands bilaterally, suggestive of adrenal haemorrhage. Laboratory and clinical manifestations exhibited life-threatening adrenal insufficiency that required hydrocortisone administration. The patient developed systemic lupus erythematosus, diagnosed 12 months later.

CONCLUSIONS

This patient with LAHPS developed rare adrenal failure due to adrenal haemorrhage, a life-threatening event that should be recognized and treated early. In our case, renal dysfunction was also observed when systemic lupus erythematosus was diagnosed 1 year after LAHPS. Our case emphasizes that early recognition of adrenal failure and careful long-term observation is required in patients with autoantibodies.

Pulmonary Hemosiderosis in a Child With Systemic Lupus Erythematosus: A Rare Presentation

Pulmonary hemorrhage is an uncommon manifestation in children and is often associated with systemic lupus erythematosus. We report a case of an adolescent girl who presented to our hospital with recurrent episodes of fever, cough, and breathlessness. Later on, she was diagnosed with pulmonary hemosiderosis as a manifestation of systemic lupus erythematosus. She was started on immunosuppressive therapy initially with prednisolone and subsequently with azathioprine and hydroxychloroquine, which improved the clinical status of the child.

Systemic lupus erythematosus and diffuse alveolar hemorrhage, etiology and novel treatment strategies

Diffuse alveolar hemorrhage is a severe respiratory complication of systemic lupus erythematosus. The illness develops over hours to a few days and is the systemic lupus erythematosus-associated syndrome with highest mortality. Although no specific symptoms have been identified, a number of features are associated with diffuse alveolar hemorrhage, with a drop in blood hemoglobin the most prominent. Dyspnea, blood-stained sputum, diffuse infiltrates identified by chest imaging, elevated single breath-diffusing capacity for monoxide, thrombocytopenia and C3 hypocomplementemia are other commonly reported signs of diffuse alveolar hemorrhage. The etiology is not completely understood but many patients develop diffuse alveolar hemorrhage concomitant with lupus nephritis, suggesting immune complex-driven pathology. Biopsy studies have identified both cases with capillaritis and a bland non-inflammatory phenotype. An animal model of diffuse alveolar hemorrhage has indicated requirement of B lymphocytes and complement receptor-mediated apoptotic body phagocytosis by monocytes as part of the pathogenesis. This review will discuss considerations when diagnosing the condition and available therapies. Infections and other causes of hemorrhage have to be excluded as these require different treatment strategies. Methylprednisolone and cyclophosphamide remain the most commonly used therapies. Plasmapheresis and rituximab are other beneficial treatment options. A few studies have also considered intrapulmonary Factor VII therapy, extracorporeal membrane oxygenation and mesenchymal stem cell therapy. There is an unmet need of better definition of diffuse alveolar hemorrhages etiology and pathology for development of improved treatment strategies.

[Diffuse alveolar hemorrhage in children]

Diffuse alveolar hemorrhage (DAH) is a clinical syndrome with major clinical manifestations of hemoptysis, anemia, and diffuse infiltration in the lung. DAH has a high mortality rate in the acute stage and is a life-threatening emergency in clinical practice. Compared with adult DHA, childhood DHA tends to have a specific spectrum of underlying diseases. It has long been believed that idiopathic pulmonary hemosiderosis (IPH) is the main cause of childhood DAH; however, with the increase in reports of childhood DAH cases, the etiology spectrum of childhood DAH is expanding. The treatment and prognosis of DAH with different etiologies are different. This review article gives a general outline of childhood DAH, with focuses on DAH caused by IPH, systemic lupus erythematosus, anti-neutrophil cytoplasmic antibody-related vasculitis, COPA syndrome, or IgA vasculitis.

Pulmonary manifestations in systemic lupus erythematosus: pleural involvement, acute pneumonitis, chronic interstitial lung disease and diffuse alveolar hemorrhage

Systemic lupus erythematosus is the diffuse autoimmune connective tissue disease that most frequently involves pulmonary involvement, affecting 20% of 90% of the patients. The percentage varies depending on the defining criteria (symptoms, pulmonary tests or histopathological studies). At least once during the disease course, 50% of those affected have pleural and/or pulmonary manifestations, which are associated with higher morbidity and mortality. Pulmonary involvement has no correlation with lupus activity biomarkers, and it is necessary to rule out infectious processes in the initial approach. Bacterial infection is most frequently the cause of lung involvement in lupus and is one of the most important causes of death. Pulmonary involvement is considered to be primary when it is associated with disease activity, and secondary when other causes participate. Drugs have been reported to be associated with pulmonary damage, including interstitial disease. The incidence of malignant lung diseases is increased in systemic lupus erythematosus. Treatment depends on the type and severity of pulmonary involvement.

Efficacy of Rituximab in a Systemic Lupus Erythematosus Patient Presenting with Diffuse Alveolar Hemorrhage

Diffuse alveolar hemorrhage (DAH) is a life-threatening complication of systemic lupus erythematosus (SLE). Although infrequent, its mortality is very high. While there are no established therapeutic guidelines, DAH has been traditionally managed with high-dose intravenous (IV) corticosteroids, cyclophosphamide, and plasma exchange. The efficacy of alternative therapies such as rituximab has been described only in a few cases. Herein, we report a 25-year-old Hispanic man who presented with acute-onset SLE manifested by polyarthralgia, nephritis, seizures, pancytopenia, severe hypocomplementemia, and elevated anti-dsDNA antibodies. His disease course was complicated by DAH. His condition was refractory to high-dose intravenous (IV) methylprednisolone pulses, IV cyclophosphamide, and plasmapheresis. Given the lack of clinical response, he was started on IV rituximab 375 mg/m² weekly for a total of four courses. He rapidly improved after the first two doses. Over the next seven months, he did not present recurrent pulmonary symptoms. Follow-up chest computed tomography did not show residual abnormalities. This case, together with other reports, suggests that rituximab is an effective therapeutic option for DAH in SLE.