Disease activity in chronic inflammatory demyelinating polyneuropathy: A comparative study of clinical and skin biopsy markers

Abstract

Introduction/Aims: Epidermal nerve fiber involvement in chronic inflammatory demyelinating neuropathy (CIDP) has been reported in a limited number of patients.We quantified small-fiber involvement in a mixed cohort of patients with typical CIDP and CIDP variants to evaluate relationships with clinical outcome measures at different disease stages.Methods: Intraepidermal nerve fiber densities (IENFDs) were evaluated by skin punch biopsies of 23 patients with CIDP and 13 healthy controls at the forearm, thigh, and distal leg. Skin sections were optimally interpreted in all three regions in 16 CIDP patients and 10 age-and sex-matched healthy controls. Statistical analysis was performed in these subjects. Results:The IENFDs in forearm, thigh, and distal leg were similar among seven typical CIDP and nine CIDP variants. IENFDs in those regions were significantly reduced in CIDP compared with healthy controls, with a moderate negative correlation with scores on the International Neuropathy Cause and Treatment (INCAT) Upper Limb Functional Disability Scale. The reduction in IENFD compared with controls was more remarkable in the distal leg. In clinically unstable CIDP patients, the IENFDs of distal leg and forearm were significantly reduced compared with stable CIDP patients and controls. Stable CIDP patients had significantly reduced IENFDs in distal leg and forearm compared with controls.Discussion: In this exploratory study, we confirm that small fibers are also affected in CIDP. Larger studies are needed to explore longitudinal changes of IENFD in CIDP and its relation to disease stage.

Disease activity in chronic inflammatory demyelinating polyneuropathy: association between circulating B-cell subsets, cytokine levels, and clinical outcomes

“…In our study, memory B cells were not directly correlated with disability scores whereas they were negatively correlated with IENDs in distal leg. In our previous report, IENFDs in the distal leg were also negatively correlated with INCAT disability scores [ 12 ]. Different from AIDP patients, the percentages of memory B cells were still increased in CIDP patients with remission and stable disease status compared to healthy controls.…”

“…IENFD values are presented in Supplementary Table S2 . Among those subjects, the skin biopsy findings and IENFD values of 16 CIDP patients and all 10 healthy volunteers were presented in detail in a previous report [ 12 ]. In summary, healthy subjects and clinically stable CIDP patients showed abundant epidermal nerves arising from subepidermal plexuses.…”

“…Skin punch biopsies were taken unilaterally from the left side of all patients but from the affected side in multifocal CIDP patients. Skin biopsy specimens from the distal leg were used for ribonucleic acid (RNA) expression studies and processed for the IENFD as previously described [ 12 ] following quantification rules of European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) guidelines [ 13 , 14 ].…”