Anti-recoverin antibodies indicate fundus abnormalities in systemic lupus erythematosus.

OBJECTIVES: Lupus fundus abnormalities are a sight-threatening complication of systemic lupus erythematosus (SLE) and its pathogenesis remains to be studied. The aim of this study was to assess the clinical characteristics associated with the presence of anti-recoverin antibodies in patients with SLE, especially those with fundus abnormalities. METHODS: Seventy-six participants were enrolled, including 21 patients with fundus abnormalities (fundus group), 30 patients without fundus abnormalities (non-fundus group) and 25 healthy individuals. Serum anti-recoverin antibody levels were measured using enzyme-linked immunosorbent assay, and clinical and laboratory data were obtained from medical records. RESULTS: Compared with the non-fundus group, the fundus group had a higher incidence of hematuria (p < 0.05). The Systemic Erythematosus Disease Activity Index (SLEDAI) score in the fundus group was significantly higher than the non-fundus group (21.48 ± 8.06 versus 10.80 ± 5.74, p < 0.001). The levels of serum anti-recoverin antibodies in the fundus group were significantly higher than the non-fundus group (p = 0.029) or the healthy control group (p = 0.011). Anti-recoverin-negative and -positive patients differed on a number of clinical parameters, including incidence of fever, rash, antinuclear antibody, anti-dsDNA antibody, erythrocyte sedimentation rate, immunoglobulin G, complement C3 and complement C4. The average SLEDAI score of anti-recoverin-positive patients was significantly higher than anti-recoverin-negative patients (17.73 ± 8.11 versus 12.56 ± 8.37, p < 0.05). CONCLUSIONS: Anti-recoverin antibodies were related to higher disease activities in SLE, especially those with fundus abnormalities, suggesting that anti-recoverin antibodies may play an important role in the pathogenesis of fundus abnormalities in SLE.

Autoimmune basal ganglia encephalitis associated with anti-recoverin antibodies: A case report.

Autoimmune basal ganglia encephalitis causes neurological symptoms such as parkinsonism associated with basal ganglia lesions. Here, we report a case of autoimmune basal ganglia encephalitis without retinal lesions or malignancy harboring anti-recoverin antibodies. The patient was a 67-year-old Japanese woman who developed anorexia, parkinsonism, and disturbance of consciousness 7 days before admission. Brain magnetic resonance imaging showed hyperintense bilateral basal ganglia lesions on fluid-attenuated inversion recovery images. 18F-fluorodeoxyglucose-positron emission tomography showed no malignancy in the trunk, and dopamine transporter single-photon emission computed tomography with dopamine transporters revealed reduced radiotracer uptake in the basal ganglia. Further, anti-recoverin IgG antibodies were detected in serum immunoblot. Based on the clinical and imaging findings, the patient was diagnosed with autoimmune basal ganglia encephalitis with anti-recoverin antibodies and administered high-dose immunoglobulins (HD-IVIG), which led to an improvement in clinical symptoms. Anti-recoverin antibodies are paraneoplastic antibodies that explicitly bind to Ca2+-binding proteins in the retina and cause retinopathy. This pathological sequence is defined as cancer-associated retinopathy (CAR). However, in our case, autoimmune basal ganglia encephalitis developed without CAR syndrome or malignancy. Clinicians should be aware of the possibility of autoimmune basal ganglia encephalitis showing anti-recoverin antibodies but no CAR syndrome or malignancy, which should be treated with HD-IVIG therapy.

Large cell neuroendocrine carcinoma of the lung with cancer-associated retinopathy.

We report a rare case of large cell neuroendocrine carcinoma (LCNEC) of the lung with cancer-associated retinopathy (CAR). To our knowledge, only two cases of LCNEC with CAR have been reported, one in 1995 and another in 2013. CAR, typically associated with small cell lung cancer (SCLC), is one of the paraneoplastic syndromes with deterioration of visual acuity, visual field constriction, and photophobia. CAR is caused by an autoimmune system reaction against the same antigen in the tumor and retinal photoreceptor cells. To diagnose CAR, genetic retinal dystrophies or any other medical causes of retinopathy should be excluded, but there are no standard diagnostic criteria. Anti-retinal antibodies are known to be positive in CAR patients, and anti-recoverin antibodies are thought to be sensitive and specific to CAR. In our case, anti-recoverin antibodies were not detected by serum tests, but CAR could be diagnosed on the basis of ophthalmological findings including clinical symptoms, electroretinographic findings, and visual field tests. CAR with clinical features of rapid visual disorder should be considered in LCNEC patients as well as in SCLC patients.