LRP4 and hematocrit: All HT patients were negative for ab against titin, muscle specific tyrosine kinase (MuSK) receptor, low-density lipoprotein receptor-related protein 4 (LRP4), aquaporin, glutamic acid decarboxylase (GAD), voltage-gated potassium channels, acetylcholine receptor (AChr) ab, and antinuclear ab.