Withdrawal of intravenous immunoglobulin in chronic inflammatory demyelinating polyradiculoneuropathy.

Intravenous immunoglobulins are an efficacious treatment for chronic inflammatory demyelinating polyradiculoneuropathy. Biomarkers for disease activity are lacking, making the need for ongoing treatment difficult to assess, leading to potential overtreatment and high health-care costs. Our objective was to determine whether intravenous immunoglobulin withdrawal is non-inferior to continuing intravenous immunoglobulin treatment and to determine how often patients are overtreated. We performed a randomized, double-blind, intravenous immunoglobulin-controlled non-inferiority trial in seven centres in the Netherlands (Trial registration: ISRCTN 13637698; www.isrctn.com/ISRCTN13637698). Adults with clinically stable chronic inflammatory demyelinating polyradiculoneuropathy using intravenous immunoglobulin maintenance treatment for at least 6 months were included. Patients received either intravenous immunoglobulin withdrawal (placebo) as investigational treatment or continuation of intravenous immunoglobulin treatment (control). The primary outcome was the mean change in logit scores from baseline to 24-week follow-up on the patient-reported Inflammatory Rasch-Overall Disability Scale. The non-inferiority margin was predefined as between-group difference in mean change scores of -0.65. Patients who deteriorated could reach a relapse end point according to predefined criteria. Patients with a relapse end point after intravenous immunoglobulin withdrawal entered a restabilization phase. All patients from the withdrawal group who remained stable were included in an open-label extension phase of 52 weeks. We included 60 patients, of whom 29 were randomized to intravenous immunoglobulin withdrawal and 31 to continuation of treatment. The mean age was 58 years (SD 14.7) and 67% was male. The between-group difference in mean change Inflammatory Rasch-Overall Disability Scale scores was -0.47 (95% CI -1.24 to 0.31), indicating that non-inferiority of intravenous immunoglobulin withdrawal could not be established. In the intravenous immunoglobulin withdrawal group, 41% remained stable for 24 weeks, compared to 58% in the intravenous immunoglobulin continuation group (-17%; 95% CI -39 to 8). Of the intravenous immunoglobulin withdrawal group, 28% remained stable at the end of the extension phase. Of the patients in the restabilization phase, 94% restabilized within 12 weeks. In conclusion, it remains inconclusive whether intravenous immunoglobulin withdrawal is non-inferior compared to continuing treatment, partly due to larger than expected confidence intervals leading to an underpowered study. Despite these limitations, a considerable proportion of patients could stop treatment and almost all patients who relapsed were restabilized quickly. Unexpectedly, a high proportion of intravenous immunoglobulin-treated patients experienced a relapse end point, emphasizing the need for more objective measures for disease activity in future trials, as the patient-reported outcome measures might not have been able to identify true relapses reliably. Overall, this study suggests that withdrawal attempts are safe and should be performed regularly in clinically stable patients.

Borrelia burgdorferi sensu lato seroconversion after intravenous immunoglobulin treatment: A cohort study.

OBJECTIVE: Intravenous immunoglobulin (IVIg) consists of pooled donor immunoglobulins (IgG), possibly including anti-Borrelia burgdorferi (Bbsl) antibodies. Apparent IVIg-related Bbsl seroconversion could lead to incorrect diagnosis of Lyme borreliosis. This cohort study was designed to determine how often IVIg treatment leads to apparent Bbsl seroconversion and whether antibodies disappear post-treatment. METHODS: Sera from chronic inflammatory demyelinating polyneuropathy (CIDP) and myositis patients were analyzed, drawn pre-treatment and 6-12 weeks after the start of IVIg. In patients with apparent seroconversion, follow-up samples after treatment withdrawal were analyzed, if available. Patients treated with corticosteroids were included as controls. A two-tier protocol was used for serological testing consisting of the C6 Lyme ELISA (Oxford Immunotec) and confirmation by immunoglobulin M (IgM) and immunoglobulin G (IgG) immunoblot (Mikrogen® ). RESULTS: We included 61 patients: 51 patients were treated with IVIg and 10 with dexamethasone. Of the patients treated with IVIg, 42 had CIDP (82%) and were treated with Nanogam® (Sanquin Plasma Products). Nine patients had myositis (18%) and were treated with Privigen® (CSL Behring). Anti-Bbsl IgG seroprevalence pre-treatment was 3% (2/61). Apparent seroconversion during IVIg treatment occurred in 39% (20/51) of patients, all treated with Nanogam. Post-treatment seroreversion occurred in 92% (12/13) of patients with available follow-up samples; in 78% (7/9) seroreversion was observed within 3 months. CONCLUSIONS: Transient presence of anti-Bbsl IgG antibodies after IVIg is regularly observed. This effect appears to be dependent on the IVIg brand, probably reflecting variation in Bbsl exposure of plasma donors. Lyme borreliosis serological testing during, and weeks to months after, IVIg is therefore of limited utility.

Diagnostic challenges in chronic inflammatory demyelinating polyradiculoneuropathy.

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) consists of a spectrum of autoimmune diseases of the peripheral nerves, causing weakness and sensory symptoms. Diagnosis often is challenging, because of the heterogeneous presentation and both mis- and underdiagnosis are common. Nerve conduction study (NCS) abnormalities suggestive of demyelination are mandatory to fulfil the diagnostic criteria. On the one hand, performance and interpretation of NCS can be difficult and none of these demyelinating findings are specific for CIDP. On the other hand, not all patients will be detected despite the relatively high sensitivity of NCS abnormalities. The electrodiagnostic criteria can be supplemented with additional diagnostic tests such as CSF examination, MRI, nerve biopsy, and somatosensory evoked potentials. However, the evidence for each of these additional diagnostic tests is limited. Studies are often small without the use of a clinically relevant control group. None of the findings are specific for CIDP, meaning that the results of the diagnostic tests should be carefully interpreted. In this update we will discuss the pitfalls in diagnosing CIDP and the value of newly introduced diagnostic tests such as nerve ultrasound and testing for autoantibodies, which are not yet part of the guidelines.

Diagnosis and treatment response in the asymmetric variant of chronic inflammatory demyelinating polyneuropathy.

The objectives were to (a) assess the diagnostic value of testing clinically affected and unaffected limbs with nerve conduction studies (NCS) in patients with the asymmetric chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) variant and to define the most useful strategy for diagnosis, and (b) describe treatment response and long-term outcome. We performed a retrospective study and included patients with a multifocal distribution of symptoms and signs, who met the probable or definite EFNS/PNS diagnostic categories for CIDP. We included 34 patients and 32 NCS datasets were available. Of these 32 patients, 25 (78%) met the electrodiagnostic criteria for definite or probable CIDP and seven (22%) for possible CIDP. Patients fulfilling the possible electrodiagnostic criteria and a supportive criterion were considered as probable CIDP. NCS of the clinically affected forearm and leg led to a probable or definite diagnosis in 13 patients (41%). Measuring both arms up to Erb's point led to a probable or definite diagnosis in 25 patients (78%), after which NCS of both legs did not contribute to additional probable or definite diagnoses. In total, 30% of patients treated with dexamethasone and 94% of patients treated with intravenous immunoglobulins (IVIg) responded. IVIg withdrawal attempts were successful in 21% of patients. After measuring the clinically affected arm up to Erb's point, NCS of the unaffected arm to Erb's point has the highest additional diagnostic yield in patients with asymmetric CIDP. Patients seem to respond better to IVIg than to corticosteroids and long-term treatment is often required, although IVIg withdrawal was successful in 21%.

Intravenous immunoglobulins in patients with clinically suspected chronic immune-mediated neuropathy.

Intravenous immunoglobulins (IVIg) are an efficacious treatment for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and multifocal motor neuropathy (MMN). IVIg is considered in patients who have a high suspicion of an inflammatory neuropathy, but do not meet diagnostic criteria. The objective of this retrospective study was to assess which diagnostic results led to the decision to administer IVIg and to determine the rate of improvement. We included consecutive patients suspected of CIDP or MMN who did not meet the electrophysiological EFNS/PNS criteria and received IVIg treatment. Patients were included in a tertiary referral center for inflammatory neuropathies and motor neuron diseases. Thirty-five patients were included; 19 patients suspected of CIDP and 16 suspected of MMN. Nerve hypertrophy on ultrasound (80% of patients suspected of CIDP and 67% of patients suspected of MMN) and/or elevated cerebrospinal fluid (CSF) protein (53% of patients suspected of CIDP and 45% of patients suspected of MMN) were the most frequent findings that supported the diagnosis. Thirteen patients suspected of CIDP (68%) and five patients suspected of MMN (31%) responded to treatment. There was no association between the presence of the EFNS/PNS supportive criteria, including nerve hypertrophy on ultrasound, and treatment response. In conclusion, enlarged nerves on ultrasound and elevated CSF protein were the main reasons to start IVIg treatment in our study, although findings did not correlate with treatment response. In tertiary referral clinics, IVIg treatment could be considered in selected patients with a high suspicion of an inflammatory neuropathy, especially in those suspected of CIDP.

Elevated leukocyte count in cerebrospinal fluid of patients with chronic inflammatory demyelinating polyneuropathy.

Cerebrospinal fluid (CSF) examination is often part of the diagnostic work-up of a patient suspected of having chronic inflammatory demyelinating polyneuropathy (CIDP). According to the European Federation of Neurological Societies and the Peripheral Nerve Society (EFNS/PNS) criteria, an elevated protein level without pleocytosis (leukocytes <10 cells/µl) is supportive of the diagnosis CIDP. It is unclear how many CSF leukocytes are compatible with the diagnosis CIDP and how extensive the diagnostic work-up should be in patients with a demyelinating neuropathy and pleocytosis. We performed a retrospective study at two tertiary neuromuscular referral clinics and identified 14 out of 273 (6%) patients with CIDP with elevated CSF leukocytes (≥10 cells/µl). All these patients met the EFNS/PNS criteria for definite or probable CIDP. Eight patients (57%) presented with a subacute onset and four patients with an antecedent infection. Most patients responded well to therapy, and eight patients are currently in remission. In four patients, lumbar puncture was repeated. A spontaneous decrease in leukocytes before start of treatment was found in three patients. Our data indicate that a mild to moderate pleocytosis in CSF does not exclude the diagnosis of CIDP, especially in patients with a subacute onset of disease.

Continuous performance test in pediatric obsessive-compulsive disorder and tic disorders: the role of sustained attention.

OBJECTIVE: Pediatric obsessive-compulsive disorder (OCD) and tic disorders (TD) are often associated with attention-deficit hyperactivity disorder (ADHD). In order to clarify the role of attention and inhibitory control in pediatric OCD and TD, a continuous performance test (CPT) was administered to a cohort of children and adolescents with OCD alone, TD alone, and OCD+TD. METHODS: A clinical cohort of 48 children and adolescents with OCD alone (n=20), TD alone (n=15), or OCD+TD (n=13) was interviewed clinically and administered the Conners Continuous Performance Test II (CPT-II). The Conners CPT-II is a 14-minute normed computerized test consisting of 6 blocks. It taps into attention, inhibitory control, and sustained attention cognitive domains. Key parameters include errors of omission (distractability), commission (inhibitory control), and variable responding over time (sustained attention). Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV) criteria were applied in a best-estimate process to diagnose OCD, TD, ADHD, and anxiety disorders. RESULTS: Children with OCD+TD had more errors of omission (p=0.03), and more hit RT block change (p=0.003) and hit SE block change (p=0.02) than subjects with OCD alone and TD alone. These deficits in sustained attention were associated with younger age and hoarding tendencies. A clinical diagnosis of ADHD in the OCD+TD group also determined worse sustained attention. CONCLUSIONS: A deficit in sustained attention, a core marker of ADHD, is also a marker of OCD+TD, compared to OCD alone and TD alone. Biological correlates of sustained attention may serve to uncover the pathophysiology of OCD and TD through genetic and imaging studies.