Table 1.
Clinical features of patients with AAG/APD.
Fig 1.
Schematic representation of the acetylcholine receptor (AChR) α3-Gaussia luciferase (GL) 8990.
For the ganglionic AChR (gAChR)-LIPS assay, human embryonic kidney (HEK) 293 cells were transfected with an expression plasmid for the gAChRα3 or β4-GL reporter.
Fig 2.
The Luciferase Immunoprecipitation Systems (LIPS).
The soluble fractionated component from the solubilized HEK 293F cells, including the gAChRα3 or β4-GL, reacted with human serum, and the specific luciferase activities of the gAChRα3 or β4-GL were found with the luminometer. The in vitro LIPS assay can quantitatively evaluate an interaction between an antigen and an antibody with high sensitivity and without a radioisotope.
Fig 3.
Confirmation of the LIPS assay system for the gAChRα3 or β4 with ready-made antibodies.
The anti-gAChRα3 antibody (H-100) and the anti gAChRβ4 antibody (S-15) bound the gAChRα3-GL and the gAChRβ4 reporters, respectively in a dose-dependent manner (a and b). The X-axis indicates the amount of ready-made gAChRα3 or β4 antibody used. The Y-axis indicates the gAChRα3 or β4-GL activity. The line with closed diamonds shows the results that were obtained in this experiment.
Fig 4.
LIPS for gAChR in the sera from patients with autoimmune autonomic ganglionopathy (AAG) and controls.
We tested the sera from patients with AAG, disease controls (DC), and healthy controls (HC). a) Anti-gAChRα3 antibodies were detected in 23 samples. The mean anti-gAChRα3 antibody level in the HC was 0.305 antibody index (A.I.), which was significantly lower than in the AAG samples with a mean level of 1.210 A.I. (p < 0.001). b) Anti-gAChRβ4 antibodies were also detected in seven samples, as shown in Fig. 4B (p = 0.005). The mean anti-gAChRβ4 antibody level in the HC was 0.367 A.I., which was significantly lower than the measn level of 0.618 A.I. in the AAG samples (p < 0.001).
Table 2.
Clinical and autonomic characteristics at baseline of anti-gAChR Ab positive AAG patients.
Table 3.
Autonomic function tests at baseline of anti-gAChR Ab positive AAG patients.
Fig 5.
[123I] meta-iodobenzylguanidine (MIBG) cardiac imaging. Early and Delayed.
a)123I-MIBG myocardial scintigraphy revealed that the heart/mediastinum (H/M) ratio was decreased at the baseline (early, 1.55; delay, 1.32). A reduced HM ratio indicates peripheral noradrenergic depletion. b) Combined immunomodulatory therapies resulted in a remarkable improvement in the H/M ratio (early, 2.38; delay, 2.23).