Peripheral Neuropathy After Viral Eradication With Direct-acting Antivirals in Chronic HCV Hepatitis

A Prospective Study

Maria M. Zanone; Claudia Marinucci; Alessia Ciancio; Dario Cocito; Federica Zardo; Emanuela Spagone; Bruno Ferrero; Cristina Cerruti; Lorena Charrier; Franco Cavallo; Giorgio M. Saracco; Massimo Porta


Liver International. 2021;44(11):2611-2621. 

In This Article



Out-patients with a history of chronic HCV-infection, younger than 75, and eligible to start treatment with DAAs according to the EASL guidelines[20] attending the Hepatic Clinic at Turin University, were consecutively considered for participation in the study. Exclusion criteria included non compensated or advanced cirrhosis, current, and history of, alcohol or drug abuse, smoking, clinical history of diabetes or altered fasting glucose, hypothyroidism, connective tissue diseases or other forms of chronic arthritis/artropathy, vertebral discopathy, entrapment mononeuropathies, chronic kidney disease (stage IV-V), past or current malignancy. Further clinical information on BMI, previous anti-viral therapies (interferon, ribavirin), medication intake, viral genotype and load was obtained from medical records. The severity of liver disease was graduated according to the degree of liver fibrosis defined on Metavir stage, as estimated by FibroScan[21] and Child-Pugh score was calculated.[22] Blood samples were obtained for serum chemistry profile and cryoglobulin (CG) determination. Briefly, blood samples were kept at 37°C for 30 minutes before separation. Serum was prepared by centrifuging at 37°C for 10 minutes at 1245 g. The serum obtained was transferred to a 15-mL glass graduated conical tube, and incubated at 4°C for 7 days. If a precipitate was detected, the tube was centrifuged at 1245 g for 30 minutes at 4°C. The cryoprecipitate was visually measured according to the graduated level of the glass tube and expressed as a percentage of precipitate/serum volume.

Serum samples were frozen at −20°C for subsequent studies. Determination of HCV genotype with viral load were assessed and patients were treated according to guidelines for HCV infection,[20] and re-evaluated 10.4 ± 1.7 months (T1) after the ending of the 8 or 12 weeks course of DAA therapy, depending on DAA.

Informed consent was obtained and the investigations carried out in conformity with the Declaration of Helsinki. The study was approved by the local Ethics Committee.

Assessment of Neuropathy and Quality of Life

At T0, all participants received a full clinical and neurological examination, including deep tendon knee and ankle reflexes assessment and recording of vibratory perception threshold at the tip of the big toe, using a 128 Hz tuning fork. Electrophysiological tests were performed by standard equipment (Dantec™ Keypoint® G4, Natus Neurology Incorporated). Skin temperature was maintained at 36°C using infrared heating when needed, and nerve conduction studies were performed according to standard techniques.[23] Compound muscle action potential (CMAP) and sensory nerve action potential (SNAP) amplitudes were recorded by surface electrodes. Motor conduction velocity (MCV), distal latency (DL) and CMAP amplitude (baseline to negative peak) were measured in the median, ulnar, and peroneal nerves of both sides. Sensory nerve conduction velocity (SCV) and SNAP amplitude were measured in the median, ulnar, and sural nerves of both sides. Tests were performed according to standard techniques indicated by Kimura,[24] and the normality cut-off values adopted were derived from the mean ± SD of a group of 73 healthy control subjects studied in our laboratory (mean age 55.5 ± 12.7 years). Results were classified as normal, or as altered if any parameter of the nerve assessed was not within the control mean −2SD (for CAMP, MCV, SAP, SCV) or control mean +2SD (for DL).

Muscle strength was tested by the Medical Research Council (MRC) scale, which evaluates the strength of upper and lower limb movements, ranging from 0 (no contraction) to 5 (normal strength) and then adding the obtained values, according to MRC sum scores criteria.[25] Scores ranged from 0 to 80.

Structured validated questionnaires were used to identify symptoms related to motor and sensory function, as typically used for primary endpoints in inflammatory polyneuropathy clinical trials. Specifically, neuropathic pain (scale and number of reporting patients), impairment (sensory and motor scale), disability (scale), global impression of change according to improved or resolved symptoms, impacting on quality of life were evaluated.

The Douleur Neuropathique 4 (DN4)[26] tool evaluates neuropathic pain through 10 items: 7 evaluating pain quality as defined by the patient and 3 based upon clinical assessment of hypoaesthesia to touch and pinprick and allodynia. Total score derives from the sum of all 10 items and the cut-off value for neuropathic pain diagnosis is 4/10.[26] DN4 has 82%-83% sensitivity, and 81%-90% specificity.[26,27]

The Neuropathic Pain Symptom Inventory (NPSI)[28] is a self-administered questionnaire assessing spontaneous ongoing or paroxysmal pain, evoked pain and dysesthesia/paraesthesia. It is structured in 12 items, 10 on different symptoms, and 2 on duration, each quantified on a numerical scale ranging 0–10; total score was recorded.

The Sensory Sum Score (SSS)[29] comprises pin prick and vibration sense plus a two point discrimination value in the arms and legs, and ranges from 0 ("normal sensation") to 20 ("most severe sensory deficit").

The Inflammatory Neuropathy Cause and Treatment (INCAT)[30] tool measures disability of upper and lower limbs, testing the ability to use either arm for purposeful movements and to walk without support or wheelchair, respectively. Scores ranged from 0 (no disability) to 12 (severe disability).

Quality of life was evaluated using the Euro-QoL,[31] based upon self-evaluation of health-related quality of life assessing mobility, self-care, usual activities, pain/discomfort, and anxiety/depression, each with 3 levels of increasing severity. Index is then calculated subtracting from 1, the best health state, standard coefficients that increase with gravity.

Investigators studying clinical features were unaware of electrophysiology and lab testing results, as were the other investigators of the clinical data.

At T1, all patients were re-examined and questionnaires administered, and only those with abnormal electroneurography at baseline underwent a new electrophysiological study.

Statistical Analysis

Data are shown as absolute and relative (%) frequencies for categorical data and mean ± SD for continuous variables.

Mc Nemar test for categorical variables and paired t test or Wilcoxon signed-rank test, as appropriate, were carried out to detect significant differences between baseline and follow-up data for neurological characteristics of all patients and for electrophysiological data for patients who showed abnormal results at baseline.

Chi-square test for categorical variables and t test for continuous variables, or Wilcoxon rank-sum test in case of nonparametric distribution, were performed to assess whether significant differences for demographic and clinical data could be found between patients with and without abnormal electrophysiological results at baseline.

Chi-square test for categorical variables and t test for continuous variables, or Wilcoxon rank-sum test, as appropriate, were carried out to assess whether significant differences could be evidenced between CG+and CG- groups for socio-demographic, clinical and neurological data at baseline.

Differences between baseline and T1 for neurological data were then tested in both groups (GC+and GC-) with paired t test or Wilcoxon signed-rank test for continuous variables and Mc Nemar test for categorical variables. Differences between baseline and T1 (Δ) for neurological data were finally compared between CG+and GC- by means of chi-square test for categorical variables and t test or Wilcoxon rank-sum test for continuous variables, as appropriate.

For all tests, a P-value of less than 5% was considered significant.

All analyses were performed with Stata 14.