Combined pure red cell aplasia and autoimmune hemolytic anemia in systemic lupus erythematosus with anti-erythropoietin autoantibodies

A 42-year-old woman with systemic lupus erythematosus was admitted to our hospital because of severe anemia. Her bone marrow was almost normocellular and erythroblasts were nearly absent. Laboratory data showed elevated levels of lactate dehydrogenase and positive findings on Coombs' tests. On the basis of these findings, her anemia was diagnosed as the overlap of pure red cell aplasia with autoimmune hemolytic anemia. Radioimmunoprecipitation assay revealed that her serum was positive for anti-erythropoietin antibodies before therapy. Furthermore, the autoantibodies inhibited proliferation of an erythropoietin-dependent cell line in a dose-dependent manner. Immunosuppressive treatment improved the anemia accompanied with disappearance of the autoantibodies.     

IgE Receptor-Mediated Mast-Cell Renin Release

Renin is a newly discovered constituent of mast cells. Given that mast cells play a major role in IgE-mediated allergic hypersensitivity, we investigated whether activation of the high-affinity IgE receptor FcεRI elicits release of mast-cell renin. Cross-linking of FcεRI on the surface of mature bone marrow–derived mast cells elicited release of enzymatically active renin protein. The angiotensin I–forming activity of the renin protein was completely blocked by the selective renin inhibitor BILA 2157, which excludes formation of angiotensin I by proteases other than renin. FcεRI-mediated mast-cell renin release was inhibited by dexamethasone and potentiated by the proinflammatory mediator PGE₂. Furthermore, cross-linking of mast-cell FcεRI in ex vivo murine hearts passively sensitized with monoclonal anti-DNP IgE also resulted in mast-cell degranulation and overflow of renin. Our findings indicate that IgE-mediated allergic hypersensitivity provokes release of renin from both cultured and resident cardiac mast cells, a process likely to be exacerbated in a chronic inflammatory background. Given the widespread distribution of mast cells, and the presence of angiotensinogen and angiotensin-converting enzyme in many tissues, renin release in immediate hypersensitivity reactions could result in local angiotensin II generation and multiorgan dysfunctions.Mast cells (MCs) express and secrete active renin.^1–3 MCs are known to play a major role in IgE-mediated allergic reactions.^4,5 Whether immediate hypersensitivity can elicit MC renin release is a question of major basic and translational importance, given the ubiquitous presence of MCs^3,6,7 and the multiplicity of angiotensin-induced organ dysfunctions.⁸ To address this question, we used murine bone marrow–derived MCs (BMMCs) and MCs in ex vivo murine hearts. Here, we report the novel finding that specific cross-linking of the high-affinity FcεRI receptor on the surface of BMMCs and heart MCs elicits the release of enzymatically active renin protein. This process is inhibited by glucocorticoids and is enhanced by PGE₂. Similarly, cross-linking of MC FcεRI in ex vivo murine hearts resulted in MC degranulation and overflow of renin.     

Intravascular ultrasound assessment of the association between spatial orientation of ruptured coronary plaques and remodeling morphology of culprit plaques in ST-elevation acute myocardial infarction

The aim of this study was to assess the association between the spatial location of plaque rupture and remodeling pattern of culprit lesions in acute anterior myocardial infarction (MI). Positive remodeling suggests a potential surrogate marker of plaque vulnerability, whereas plaque rupture causes thrombus formation followed by coronary occlusion and MI. Intravascular ultrasound (IVUS) can determine the precise spatial orientation of coronary plaque formation. We studied 52 consecutive patients with acute anterior MI caused by plaque rupture of the culprit lesion as assessed by preintervention IVUS. The plaques were divided into those with and without positive remodeling. We divided the plaques into three categories according to the spatial orientation of plaque rupture site: myocardial (inner curve), epicardial (outer curve), and lateral quadrants (2 intermediate quadrants). Among 52 plaque ruptures in 52 lesions, 27 ruptures were oriented toward the epicardial side (52%), 18 toward the myocardial side (35%), and 7 in the 2 lateral quadrants (13%). Among 35 plaques with positive remodeling, plaque rupture was observed in 21 (52%) on the epicardial side, 12 (34%) on the myocardial side, and 2 (6%) on the lateral side. However, among 17 plaques without positive remodeling, plaque rupture was observed in 6 (35%), 6 (35%), and 5 (30%), respectively (p?=?0.047). Atherosclerotic plaques with positive remodeling showed more frequent plaque rupture on the epicardial side of the coronary vessel wall in anterior MI than those without positive remodeling.     

Three cases of pneumatosis intestinalis presenting in autoimmune diseases

Pneumatosis intestinalis (PI) is a comparatively rare disease characterized by the presence of intramural gas in the gastrointestinal tract. PI is known to be associated with several clinical conditions, such as pulmonary diseases, gastrointestinal diseases, and traumatic injury, as well as autoimmune disorders. In particular, PI is commonly seen in systemic sclerosis (SSc) but rarely in systemic lupus erythematosus and dermatomyositis (DM). In this report, we present three cases of PI presenting in autoimmune diseases, including DM, Sj?gren's syndrome, and limited SSc, and further discuss its background characteristics.     

Case of cystoid macular edema induced by systemic administration of paclitaxel: evaluations with electroretinograms

Purpose

To report abnormal full-field electroretinograms (ERGs) in a patient with cystoid macular edema (CME) induced by systemic paclitaxel.

Methods

This is an observational case report. Full-field ERGs were recorded to evaluate the retinal function using the RETeval system and conventional ERGs using contact lens electrodes with built-in white light-emitting diodes. Optical coherence tomography (OCT) was also used to assess the retinal morphology.

Results

A 70-year-old man, who was diagnosed with gastric cancer, had undergone gastrectomy. Subsequently, systemic paclitaxel was administered once a week as an adjuvant therapy. After the tenth course of paclitaxel, he experienced blurred vision in both eyes and visited our department of ophthalmology. OCT revealed the presence of CME in both eyes, and the RETeval flicker ERGs showed a marked reduction in the amplitudes and a prolongation of the implicit times in both eyes. Conventional ERGs showed that the amplitudes of the oscillatory potentials (OPs) were also severely attenuated. The abnormal OCT findings and reduced visual acuity recovered to normal at 1 and 2 months, respectively, after the discontinuation of paclitaxel. However, the flicker ERGs did not recover to normal values until 4 months after the discontinuation of paclitaxel.

Conclusion

These results suggest that the ERGs can be used to monitor the changes in the overall retinal function in patients receiving paclitaxel.