Plasmapheresis in Amyotrophic Lateral Sclerosis With Autoantibody Against NRIP 2 (PALADIN2)

Change in disease progression rates measuring using ALSFRS-R (Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised)

Difference between \[(ALSFRS-R at month -3 - ALSFRS-R at month 0)/3\] and \[(ALSFRS-R at month 0 - ALSFRS-R at month 12)/12\]; Months -3 to 0 vs. Months 0 to 12; the higher above ratio means higher disease progression rate

Time frame: 15 months

Change in disease progression rates measuring using ALSFRS-R (Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised)

Difference between \[(ALSFRS-R at month -3 - ALSFRS-R at month 0)/3\] and \[(ALSFRS-R at month 0 - ALSFRS-R at month 3)/3\]; Months -3 to 0 vs. Months 0 to 3; the higher above ratio means higher disease progression rate

Time frame: 6 months

Change in disease severity measuring using ALSFRS-R (Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised)

The ALSFRS-R at months 3, 6, 9,12 as compared to that at month 0; the lower the AFSFRS-R, the worse disease severity

Time frame: 12 months

Change in disease progression rates measuring using MRC (Medical Research Council score) mega-score

Difference between \[(MRC mega-score at month -3 - MRC mega-score at month 0)/3\] and \[(MRC mega-score at month 0 - MRC mega-score at month 12)/12\]; Months -3 to 0 vs. Months 0 to 12; the higher above ratio means higher disease progression rate

Time frame: 15 months

Change in disease progression rates measuring using Grips force (lb)

Description: Difference between \[(Grips force at month -3 - Grips force at month 0)/3\] and \[(Grips force at month 0 - Grips force at month 12)/12\]; Months -3 to 0 vs. Months 0 to 12; the higher above ratio means higher disease progression rate

Time frame: 15 months

Change in disease progression rates measuring using 6MWT (6 minute walking test); distance in meters

Difference between \[(distance at month -3 - distance at month 0)/3\] and \[(distance at month 0 - distance at month 12)/12\]; Months -3 to 0 vs. Months 0 to 12; the higher above ratio, the higher disease progression rate

Time frame: 15 months

Change in disease progression rates measuring using EQ-5D (EuroQol Group Life Quality Score)

Difference between \[(Score at month -3 - Score at month 0)/3\] and \[(Score at month 0 - Score at month 12)/12\]; Months -3 to 0 vs. Months 0 to 12; the higher above ratio means higher disease progression rate

Time frame: 15 months

Change in disease progression rates measuring using respiratory vital capacity (standardized vital capacity, %)

Difference between \[(vital capacity -3 - vital capacity at month 0)/3\] and \[(vital capacity at month 0 - vital capacity at month 12)/12\]; Months -3 to 0 vs. Months 0 to 12; the higher above ratio means higher disease progression rate

Time frame: 15 months

Change in disease progression rates measuring using CMAP (compound muscle action potential, mV)

Difference between \[(CMAP -3 - CMAP at month 0)/3\] and \[(CMAP at month 0 - CMAP at month 12)/12\]; Months -3 to 0 vs. Months 0 to 12; the higher above ratio means higher disease progression rate

Time frame: 15 months

Change in disease progression rates measuring using MUNE (motor unit number estimation; number)

Difference between \[(MUNE -3 - MUNE at month 0)/3\] and \[(MUNE at month 0 - MUNE at month 12)/12\]; Months -3 to 0 vs. Months 0 to 12; the higher above ratio means higher disease progression rate

Time frame: 15 months

Change in disease severity measuring using plasma NF-L (Neurofilament-light chain; pg/mL)

The NF-L at months 3, 6, 9,12 as compared to that at month 0; the lower the NF-L, the milder disease activity

Time frame: 12 months

Any side effect under plasmapheresis

Time frame: 12 months