Clinical Characterization of Definite Autoimmune Limbic Encephalitis: A 30-case Series.

Objective Limbic encephalitis (LE) is an inflammatory condition of the limbic system that has an acute or subacute onset. Several types of antibodies are related to the onset of LE, including anti-N-methyl D-aspartate receptor (NMDAR) antibodies and voltage-gated potassium channel (VGKC)-complex antibodies. However, the characteristics and prevalence of LE remain unclear, especially in Asian cohorts, due to the rarity. We aimed to survey their characteristics. Materials and Methods Data of 30 cases clinically defined as "definite autoimmune LE" (based on the standard criteria) were retrospectively collected. These patients were categorized into four subtypes: NMDAR (+) (n=8), VGKC (+) (n=2), antibodies related to paraneoplastic syndrome (n=2), and an antibody-negative group (uncategorized) (n=18). Results LE is rare in Japan, and affected only 30 of 16,759 hospital patients (0.2%) over a ten-year period. The NMDAR (+) group showed distinctive symptoms, while the other three groups had similar indications. Brain MRI indicated significant medial temporal lobe atrophy at one year follow up after discharge. The prevalence of cognitive dysfunction as a complication was 64% (9/14). First-line immunotherapy resulted in a good outcome. A drastic improvement was seen from 4.0±1.1 to 1.1+ on the modified Rankin Scale. A good treatment outcome was observed in all groups (NMDAR, VGKC, and uncategorized), suggesting the importance of an early clinical diagnosis and the early initiation of treatment. Furthermore, we reviewed 26 cases that were clinically diagnosed as definitive autoimmune LE in previous case reports. Conclusion Our findings show that the establishment of a clinical diagnosis based on the clinical criteria of definitive autoimmune LE is important for the initiation of immunotherapy.

Epiplakin Is a Paraneoplastic Pemphigus Autoantigen and Related to Bronchiolitis Obliterans in Japanese Patients.

All plakin family proteins are known to be autoantigens in paraneoplastic pemphigus (PNP). In this study, we first examined whether PNP sera also react with epiplakin, another plakin protein, by various immunological methods using 48 Japanese PNP sera. Immunofluorescence confirmed that cultured keratinocytes expressed epiplakin. Epiplakin was detected by 72.9% of PNP sera by immunoprecipitation-immunoblotting with KU-8 cell extract, but not by immunoblotting of either normal human epidermal extract or KU-8 cell extract. Epiplakin was essentially not detected by 95 disease and normal control sera. Statistical analyses of various clinical and immunological findings revealed a significant correlation of the presence of anti-epiplakin antibodies with both bronchiolitis obliterans and mortality. No epiplakin-negative PNP case developed bronchiolitis obliterans. However, although 29.4% of European patients with PNP had bronchiolitis obliterans, significant correlation with anti-epiplakin autoantibodies was not observed. In further studies for lung, immunofluorescence showed the presence of epiplakin in normal human lung, particularly respiratory bronchiole, immunoprecipitation-immunoblotting showed that PNP sera reacted with epiplakin in cultured lung cells, and mice injected with polyclonal antibody specific to epiplakin histopathologically showed abnormal changes in small airway epithelia. These results indicated that epiplakin is one of the major PNP autoantigens and is related to PNP-related bronchiolitis obliterans.

Coloration of fundus lesions in bilateral diffuse uveal melanocytic proliferation.

PURPOSE: To report differences in the coloration of fundus lesions between Asian and Caucasian patients with bilateral diffuse uveal melanocytic proliferation (BDUMP). CASES: This syndrome was detected in 2 Japanese patients, 69 and 73 years old, with lung cancer who visited our department complaining of visual disturbances. The coloration of the fundus lesions was investigated in these 2 patients. RESULTS: The fundus lesions in the first patient appeared gray or grayish-brown in color at the first visit. Six months later, the fundus appeared as a mixture of white to dark-brown lesions. The fundus in the second patient exhibited a mixture of white, gray, and dark-brown lesions from the first visit. CONCLUSIONS: The fundus lesions in these BDUMP patients appeared gray or grayish-brown in color at the early stage of the disease, probably because of the abundance of melanin pigments in the uveal melanocytes. At the advanced stage, the fundus exhibited a mixture of dark-brown lesions due to melanin deposits and white, depigmented lesions caused by atrophy and/or necrosis of the melanocytes.