Randomized trial of facilitated subcutaneous immunoglobulin in multifocal motor neuropathy.

BACKGROUND AND PURPOSE: To optimize subcutaneous therapy with immunoglobulins, large volume infusion of immunoglobulin G facilitated by pretreatment with hyaluronidase (fSCIG) was compared to conventional infusion of multiple small dosages (cSCIG) in 20 patients with multifocal motor neuropathy. METHODS: A randomized, non-inferiority and observer-blinded cross-over design was applied with a treatment period of 24 weeks for each therapy. RESULTS: In 18 patients fSCIG was feasible, two patients leaving the study due to side-effects. The primary study variable, isometric strength, was unchanged, being 100.8% [95% confidence interval (CI) 94.8%-107.1%) in fSCIG and 105.9% (95% CI 99.8%-112.0%) in cSCIG. Secondary end-points of disability, functions, impairments and quality of life showed no differences between the two treatments. Mild and short-lasting generalized side-effects were similar in the two groups, whereas the relative frequency of localized side-effects at the injection site was increased after fSCIG [0.63 (95% CI 0.23-1.00) vs. 0.09 (95% CI 0.00-0.22), P = 0.005]. The preference of the patients favoured fSCIG for two out of five visual analogue scale scores as well as the total mean score of all preferences (P = 0.03). CONCLUSIONS: Facilitated SCIG seems effective, feasible and safe. In addition, it is preferred by patients but is accompanied by a higher frequency of short-lasting localized side-effects.

Subcutaneous immunoglobulin as first-line therapy in treatment-naive patients with chronic inflammatory demyelinating polyneuropathy: randomized controlled trial study.

BACKGROUND AND PURPOSE: Subcutaneous immunoglobulin (SCIG) is effective as maintenance treatment in chronic inflammatory demyelinating polyneuropathy (CIDP). We investigated whether multiple subcutaneous infusions are as effective as conventional therapy with intravenous loading doses in treatment-naive patients with CIDP. METHODS: Twenty patients fulfilling the clinical and electrophysiological criteria for CIDP were included and treated with either SCIG (0.4 g/kg/week) for 5 weeks or intravenous immunoglobulin (IVIG) (0.4 g/kg/day) for 5 days. After 10 weeks, patients were switched to the opposite treatment arm and followed for a further 10 weeks. All participants were evaluated at weeks 0, 2, 5 and 10 during both therapies. Primary outcome was combined isokinetic muscle strength (cIKS). Secondary outcomes were disability, clinical evaluation of muscle strength and the performance of various function tests. RESULTS: All participants received both therapies, 14 completing the protocol. Overall, cIKS increased by 7.4 ± 14.5% (P = 0.0003) during SCIG and by 6.9 ± 16.8% (P = 0.002) during IVIG, the effect being similar (P = 0.80). Improvement of cIKS peaked 2 weeks after IVIG and 5 weeks after SCIG. Disability improved during SCIG treatment only. Muscle strength determined by manual muscle testing improved after 5 and 10 weeks during SCIG but only after 5 weeks during IVIG. The remaining parameters improved equally during both treatments. Plasma immunoglobulin G levels at baseline and improvement of cIKS were related. CONCLUSION: In treatment-naive patients with CIDP, short-lasting SCIG and IVIG therapy improve motor performance to a similar degree, but with earlier maximal improvement following IVIG than SCIG treatment.

The electrophysiological response to immunoglobulin therapy in chronic inflammatory demyelinating polyneuropathy.

OBJECTIVE: To characterize changes in motor nerve conduction studies (MNCS) and motor unit number index (MUNIX) following treatment with subcutaneous immunoglobulin and to assess whether these changes are related to muscle strength. METHODS: Data from 23 patients participating in a randomized, controlled trial were analyzed. MNCS and MUNIX were performed before and after 12 weeks of treatment. Isokinetic strength (IMS) was measured in various muscles together with grip strength (GS). RESULTS: Proximally evoked compound muscle action potential (CMAP) amplitudes and MUNIX tended to be better preserved in treated patients (P=.049 and .045). Changes in other parameters did not differ between groups. There was no correlation between changes in electrophysiological parameters and IMS. Changes in GS were related to median nerve motor conduction velocity, distal motor latency, CMAP amplitudes, and distally evoked CMAP duration (P=.013-.035). CONCLUSION: Proximally evoked CMAP amplitudes appear to be the best MNCS parameter to assess treatment outcome in chronic inflammatory demyelinating polyneuropathy.

Subcutaneous immunoglobulin preserves muscle strength in chronic inflammatory demyelinating polyneuropathy.

BACKGROUND AND PURPOSE: Subcutaneous immunoglobulin (SCIG) is superior to placebo treatment for maintenance of muscle strength during 12 weeks in patients with chronic inflammatory demyelinating polyneuropathy (CIDP). The present study evaluated whether SCIG preserves muscle strength for 1 year in an open-label follow-up study. METHODS: Seventeen responders to intravenous immunoglobulin (IVIG) who had participated in the previous study of SCIG versus placebo in CIDP were included. After one IVIG infusion 2 weeks prior to baseline, all continued on SCIG treatment at weekly equal dosage and were evaluated after 3, 6 and 12 months. Primary end-points were changes in muscle strength evaluated by isokinetic dynamometry in four affected muscle groups and a composite score of muscle performance and function tests, including Medical Research Council (MRC) score, grip strength, 40-m walking test (40-MWT) and nine-hole peg test (9-HPT). Secondary end-points were changes of each of the listed parameters at each time point as well as an overall disability sum score (ODSS). RESULTS: The dose of SCIG was significantly unaltered during the follow-up period. Overall the isokinetic dynamometry value increased by 7.2% (P = 0.033) and after 3, 6 and 12 months by 5.7%, 8.2% and 6.8% (ns). The overall composite score at all time intervals and for each interval remained unchanged. Amongst the secondary parameters the MRC score increased significantly by 1.7% (P = 0.007), whereas grip strength, 40-MWT, 9-HPT and ODSS remained unchanged. CONCLUSION: SCIG preserves muscle strength and functional ability in patients with CIDP who previously responded to IVIG. SCIG should be considered as an alternative in long-term treatment of CIDP patients.

Hemolytic anemia following high dose intravenous immunoglobulin in patients with chronic neurological disorders.

BACKGROUND AND PURPOSE: High dose intravenous immunoglobulin (IVIG) is an established treatment for various neuromuscular disorders. Recently, cases of hemolytic anemia following IVIG have been observed. The objective of this study was to determine the extent of anemia and hemolysis after IVIG and its relationship to the AB0 blood type system. METHODS: In a prospective study 34 de novo treated patients were given 2.0 g/kg bodyweight of Privigen and 50 patients received either Privigen [n = 28; 1.53 ± 0.4 g/kg (mean ± SD)] or Kiovig (n = 22; 1.7 ± 0.4 g/kg) as maintenance therapy. The de novo patients all had a post-polio syndrome, whereas the remaining patients received maintenance therapy for the neuromuscular disorders chronic inflammatory demyelinating polyradiculoneuropathy and multifocal motor neuropathy. Blood sampling was performed before and 2 weeks after infusion of IVIG. RESULTS: Following IVIG treatment blood hemoglobin declined from 8.6 ± 0.9 to 8.0 ± 1.2 mM, P < 0.001. Reticulocyte counts and levels of bilirubin and lactate dehydrogenase were increased and haptoglobin levels decreased. The decline of hemoglobin was 0.9 ± 1.2 mM after de novo therapy versus 0.4 ± 0.8 mM after maintenance therapy with Privigen (P = 0.05) and 0.2 ± 0.3 mM after maintenance therapy with Kiovig (P = 0.47). In de novo patients compared with patients on maintenance therapy reticulocyte count and lactate dehydrogenase level increased whereas haptoglobin level decreased. Anemia correlated with the AB0 blood type system with a significant difference between type 0 (n = 17; +0.3 ± 0.4 mM) and type A, B and AB (n = 48; -1.0 ± 1.0 mM), anemia being most pronounced in type AB. CONCLUSION: Moderate hemolytic anemia is a concomitant complication of high dose IVIG in subjects with blood types A, B and AB.

Subcutaneous immunoglobulin in responders to intravenous therapy with chronic inflammatory demyelinating polyradiculoneuropathy.

BACKGROUND AND PURPOSE: We hypothesized that subcutaneous administration of immunoglobulins (SCIG) in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is feasible, safe and superior to treatment with saline for the performance of muscle strength. METHODS: Thirty patients with motor involvement in maintenance therapy with intravenous immunoglobulin (IVIG) fulfilling the EFNS/PNS criteria for CIDP, aged 18-80 years, were randomized either to SCIG at a dose corresponding to their pre-study IVIG dose or to subcutaneous saline given twice or thrice weekly for 12 weeks at home. At the start and end of the trial as well as 2 weeks before (-2, 0, 10, 12 weeks), isokinetic strength performance of four predetermined and weakened muscle groups was measured. Also, an Overall Disability Sum Score (ODSS), 40-m-walking test (40-MWT), nine-hole-peg test, Neurological Impairment Score (NIS), Medical Research Council (MRC) score, grip strength, standardized electrophysiological recordings from three nerves, and plasma IgG levels were evaluated. RESULTS: SCIG treatment was well tolerated in all 14 patients. Six patients complained of mild side-effects at the injection site. In the SCIG group there was an increase of isokinetic muscle strength of 5.5 ± 9.5% (P < 0.05) as compared with a decline of 14.4 ± 20.3% (P < 0.05) in the placebo group; the difference between the two groups being significant (P < 0.01). ODSS, NIS, MRC, grip strength and 40-MWT improved following SCIG versus saline. CONCLUSIONS: SCIG treatment in CIDP is feasible, safe and effective, and seems an attractive alternative to IVIG.

Pulmonary apelin levels and effects in rats with hypoxic pulmonary hypertension.

BACKGROUND: The peptide apelin is localised in the vascular endothelium and highly expressed in pulmonary tissue. The aim of this study was to investigate whether apelin could be a potential lung-derived plasma marker for pulmonary hypertension, and study the effect of apelin in pulmonary arteries. METHODS: Apelin protein levels were measured in the lung, right ventricle, and plasma from normoxic and chronic hypoxic rats with pulmonary hypertension. Isolated intrapulmonary arteries were mounted in microvascular myographs and the effect of apelin investigated. Finally, the distribution of apelin receptors in pulmonary tissue was visualised by immunohistochemistry. RESULTS: Total pulmonary apelin content was not changed by hypoxia. Right ventricular apelin concentrations and content were lower than in the lung, but increased substantially in hypoxia in correlation with right ventricular pressure. Plasma apelin did not reflect pulmonary or right ventricular apelin levels. In pulmonary arteries from normoxic rats, apelin inhibited vasoconstriction to endothelin-1 and angiotensin-II. However, in arteries from hypoxic rats, apelin failed to inhibit contraction to angiotensin-II and endothelin-1. No difference in immunoreaction for apelin receptors was found in lung sections and arteries from normoxic versus chronic hypoxic rats. CONCLUSIONS: Apelin changes in the right ventricle seem more specific for pulmonary hypertension than do changes in pulmonary tissue, which does not speak in favour of apelin as a lung-derived marker for this disease. During normoxic conditions, apelin has a modulating effect on vasoconstriction which is lost in chronic hypoxia. This may reflect alterations in the signal transduction downstream of the apelin receptor.