Joost L. M. Jongen

Mechanisms of peripheral neuropathy associated with bortezomib and vincristine in patients with newly diagnosed multiple myeloma: a prospective analysis of data from the HOVON-65/GMMG-HD4 trial.

BACKGROUND Bortezomib-induced peripheral neuropathy is a dose-limiting toxicity in patients with multiple myeloma, often requiring adjustment of treatment and affecting quality of life. We investigated the molecular profiles of early-onset (within one treatment cycle) versus late-onset (after two or three treatment cycles) bortezomib-induced peripheral neuropathy and compared them with those of vincristine-induced peripheral neuropathy during the induction phase of a prospective phase 3 trial. METHODS In the induction phase of the HOVON-65/GMMG-HD4 trial, patients (aged 18-65 years) with newly diagnosed Salmon and Durie stage 2 or 3 multiple myeloma were randomly assigned to three cycles of bortezomib-based or vincristine-based induction treatment. We analysed the gene expression profiles and single-nucleotide polymorphisms (SNPs) of pretreatment samples of myeloma plasma cells and peripheral blood, respectively. This study is registered, number ISRCTN64455289. FINDINGS We analysed gene expression profiles of myeloma plasma cells from 329 (39%) of 833 patients at diagnosis, and SNPs in DNA samples from 369 (44%) patients. Early-onset bortezomib-induced peripheral neuropathy was noted in 20 (8%) patients, and 63 (25%) developed the late-onset type. Early-onset and late-onset vincristine-induced peripheral neuropathy was noted in 11 (4%) and 17 (7%) patients, respectively. Significant genes in myeloma plasma cells from patients that were associated with early-onset bortezomib-induced peripheral neuropathy were the enzyme coding genes RHOBTB2 (upregulated by 1·59 times; p=4·5×10(-5)), involved in drug-induced apoptosis, CPT1C (1·44 times; p=2·9×10(-7)), involved in mitochondrial dysfunction, and SOX8 (1·68 times; p=4·28×10(-13)), involved in development of peripheral nervous system. Significant SNPs in the same patients included those located in the apoptosis gene caspase 9 (odds ratio [OR] 3·59, 95% CI 1·59-8·14; p=2·9×10(-3)), ALOX12 (3·50, 1·47-8·32; p=3·8×10(-3)), and IGF1R (0·22, 0·07-0·77; p=8·3×10(-3)). In late-onset bortezomib-induced peripheral neuropathy, the significant genes were SOD2 (upregulated by 1·18 times; p=9·6×10(-3)) and MYO5A (1·93 times; p=3·2×10(-2)), involved in development and function of the nervous system. Significant SNPs were noted in inflammatory genes MBL2 (OR 0·49, 95% CI 0·26-0·94; p=3·0×10(-2)) and PPARD (0·35, 0·15-0·83; p=9·1×10(-3)), and DNA repair genes ERCC4 (2·74, 1·56-4·84; p=1·0×10(-3)) and ERCC3 (1·26, 0·75-2·12; p=3·3×10(-3)). By contrast, early-onset vincristine-induced peripheral neuropathy was characterised by upregulation of genes involved in cell cycle and proliferation, including AURKA (3·31 times; p=1·04×10(-2)) and MKI67 (3·66 times; p=1·82×10(-3)), and the presence of SNPs in genes involved in these processes-eg, GLI1 (rs2228224 [0·13, 0·02-0·97, p=1·18×10(-2)] and rs2242578 [0·14, 0·02-1·12, p=3·00×10(-2)]). Late-onset vincristine-induced peripheral neuropathy was associated with the presence of SNPs in genes involved in absorption, distribution, metabolism, and excretion-eg, rs1413239 in DPYD (3·29, 1·47-7·37, 5·40×10(-3)) and rs3887412 in ABCC1 (3·36, 1·47-7·67, p=5·70×10(-3)). INTERPRETATION Our results strongly suggest an interaction between myeloma-related factors and the patients genetic background in the development of treatment-induced peripheral neuropathy, with different molecular pathways being implicated in bortezomib-induced and vincristine-induced peripheral neuropathy.

Pain in Guillain-Barre syndrome: a long-term follow-up study.

Background: Pain in Guillain-Barré syndrome (GBS) may be pronounced and is often overlooked. Objectives: To obtain detailed information about pain in GBS and its clinical variants. Methods: This was a prospective cohort study in 156 patients with GBS (including 18 patients with Miller Fisher syndrome [MFS]). We assessed the location, type, and intensity of pain using questionnaires at standard time points during a 1-year follow-up. Pain data were compared to other clinical features and serology. Results: Pain was reported in the 2 weeks preceding weakness in 36% of patients, 66% reported pain in the acute phase (first 3 weeks after inclusion), and 38% reported pain after 1 year. In the majority of patients, the intensity of pain was moderate to severe. Longitudinal analysis showed high mean pain intensity scores during the entire follow-up. Pain occurred in the whole spectrum of GBS. The mean pain intensity was predominantly high in patients with GBS (non-MFS), patients with sensory disturbances, and severely affected patients. Only during later stages of disease, severity of weakness and disability were significantly correlated with intensity of pain. Conclusions: Pain is a common and often severe symptom in the whole spectrum of GBS (including MFS, mildly affected, and pure motor patients). As it frequently occurs as the first symptom, but may even last for at least 1 year, pain in GBS requires full attention. It is likely that sensory nerve fiber involvement results in more severe pain.

Immunocytochemical localization of GDNF in primary afferents of the lumbar dorsal horn

IMMUNOCYTOCHEMISTRY was used to identify glial cell line-derived neurotrophic factor (GDNF) in rat spinal cord. Strong GDNF labeling was found in fibers and terminals in laminae I and II (outer) and to a lesser extent in the remaining laminae. A few spinal ganglion cells also contained GDNF. After dorsal root transection GDNF disappeared from the dorsal horn and after dorsal root ligation there was accumulation of GDNF only on the ganglion side of the ligation. These findings demonstrate anterograde transport of GDNF within primary afferent fibers, which constitute the only source of GDNF labeling in the dorsal horn. The strong presence of GDNF in the superficial dorsal horn may indicate that GDNF has a role in pain transmission in the adult rat spinal cord.

Dealing with Neuropathy in Plasma-Cell Dyscrasias

Peripheral neuropathy (PN) is a frequent complication of plasma-cell dyscrasias such as monoclonal gammopathy of undetermined significance, multiple myeloma, Waldenströms disease, POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes) syndrome, Castlemans disease, and light-chain amyloidosis. PN can be associated with the underlying disease or it can related to the treatment. The novel immunomodulatory drugs thalidomide and lenalidomide and the proteasome inhibitor bortezomib have changed the standard treatment of multiple myeloma. Treatment-related PN induced by thalidomide (TiPN) or bortezomib (BiPN) has become the most frequent cause of symptomatic polyneuropathy in multiple myeloma and related diseases. Dealing with PN has become a major challenge in current clinical practice for multiple myeloma patients. This review deals with practical issues such as etiology, incidence, symptoms, and clinical management of treatment-emergent PN. The major focus of the hematologist should be on the prevention of PN, primarily by frequent monitoring of the patient and by timely and adequate dose reduction of thalidomide and bortezomib. Thalidomide should not be given for periods longer than 18 months, and if it is, then patients should be carefully monitored with a low threshold for discontinuation in the face of any emergent neuropathy. In the case of BiPN, the dose of bortezomib should be reduced and/or the administration interval should be prolonged from biweekly to weekly. Adequate pain management and supportive care require a multidisciplinary approach involving the treating physician, expert nursing staff, and a neurologist as clinically indicated.

Anti-Ri positive opsoclonus-myoclonus-ataxia in ovarian duct cancer

Sirs: Opsoclonus-myoclonus-ataxia (OMA) is a rare but well-characterised clinical syndrome. The finding of anti-Ri antibodies in OMA is highly specific for an underlying cancer (paraneoplastic OMA). AntiRi antibodies and OMA have mainly been associated with breast cancer and rarely with small cell lung cancer, bladder cancer or cancer of the ovarian duct [1, 7, 9, 10]. A 58-year-old woman without previous neurological disease was admitted with “trembling images” and gait instability for the past 6 days. On examination there was a counter-clockwise rotatory nystagmus on looking upward, which progressed to opsoclonus in 2 weeks. She also had cervical myoclonic jerks, progressive truncal and limb ataxia and was unable to walk without support. Opsoclonus was confirmed with electronystagmography. Magnetic resonance imaging (MRI) on admission and 2 weeks later was normal. Two lumbar punctures were performed. Cerebrospinal fluid (CSF) cell count and protein were slightly elevated (126/3 and 218/ 3 mm3, 0.54 and 0.74 g/l, respectively). No malignant cells were found in the CSF. Antibodies to neurotrophic viruses did not show a significant titre-rise in serum or CSF. Stool cultures were negative for pathogenic bacteria. Using previously described immunofluorescence and Western blotting techniques, we found strong immunoreactivity in serum and CSF [8]. Anti-Ri reactivity was confirmed on Western blotting with recombinant Ri fusion protein as substrate [2]. Titres of anti-Ri were 1:12,800 in serum and 1:512 in CSF. The anti-Ri index was 3.5, indicating intrathecal production of antiRi antibodies [4]. On screening for a malignancy, an increased CA-125 (1669 × 103 U/l) was found, and ultrasonic examination revealed a cystic right adnexal mass, which on laparotomy proved to be an anaplastic adenocarcinoma of the ovarian duct. We found no confirmation of anti-Ri reactivity in the tumour tissue [6]. Three weeks after admission, she underwent total abdominal hysterectomy and bilateral salpingo-ovariectomy, followed by radiotherapy and adjuvant chemotherapy with cis-platinum and paclitaxel. Improvement began 1 week after the operation. Following prednisone, 60 mg daily, she improved even further. The course of the disease was complicated by post-transfusion purpura, for which she received five plasma exchanges. Finally, 2 months after admission, opsoclonus and myoclonus had almost disappeared and she was able to read again. Ataxia also improved, and she could walk again without support. Prednisone was tapered. Titres of anti-Ri antibodies were 1:102,400 in serum and 1:64 in CSF; the anti-Ri index was 0.1. There was no evidence of tumour relapse, and CA-125 gradually decreased to 229 × 103 U/l 5 months after admission. Most OMA patients with anti-Ri antibodies suffer from breast cancer, although one case with small cell lung cancer, one with bladder cancer and one other case with ovarian duct cancer have been reported [1, 7, 9, 10]. Three anti-Ri positive cases were identified in OMA without detectable cancer [3, 4, 7]. Since antiRi antibodies have a high predictive value for an underlying malignancy, we performed extensive investigations, including screening for gynaecological malignancies [9]. Because the number of patients is small and because spontaneous remissions occur, no reliable data on optimal treatment exist. After a combined treatment, our patient improved clinically, and anti-Ri titres in CSF decreased. This suggests a pathogenic role for intrathecally produced antiRi antibodies, although it remains to be proven whether they are directly pathogenic by cross-reacting with tumour-epitopes and neuronal antigens [5]. We found no confirmation of cross-reactivity with tumour-epitopes, but it is known that prolonged fixation of tissue in formalin destroys Ri antigenic reactivity [7]. In conclusion, in patients with OMA and anti-Ri antibodies one must be aware of a possible underlying malignancy, mainly breast cancer. Additionally, association with ovarian duct, bladder and small cell lung cancer must be considered. The role of anti-Ri antibodies in pathogenesis is still unclear.

Intrathecal injection of GDNF and BDNF induces immediate early gene expression in rat spinal dorsal horn

Glial cell line-derived neurotrophic factor (GDNF) and brain-derived neurotrophic factor (BDNF) are potent trophic factors for dorsal root ganglion cells. In addition, these factors are produced in subsets of dorsal root ganglion cells and transported anterogradely to their terminals in the superficial dorsal horn of the spinal cord, where they constitute the only source of GDNF and BDNF. We investigated the effect of 10 mug GDNF and BDNF injected by lumbar puncture on the expression of the immediate early gene (IEG) products c-Fos, c-Jun, and Krox-24 in the adult rat dorsal horn. In the dorsal horn of S1 spinal segments, GDNF and BDNF induced a strong increase in IEG expression, which was most pronounced in laminae I and II (2.9- to 4.5-fold). More distal from the injection site, in the dorsal horn of L1/L2 spinal segments, the increase in IEG expression was less pronounced, suggesting a concentration-dependent effect. In order to explain the effects of intrathecally injected GDNF, we investigated whether lumbo-sacral dorsal horn neurons expressed RET protein, the signal-transducing element of the receptor complex for GDNF. It was found that several of these neurons contained RET immunoreactivity and that some of the RET-labeled neurons had the appearance of nociceptive-specific cells, confirming their presumed role in pain transmission. Additionally, using double-labeling immunofluorescence combined with confocal microscopy, it was found that after intrathecal GDNF injection 35% of c-Fos-labeled cells were also labeled for RET. These results demonstrate that intrathecally administered GDNF and BDNF induce IEG expression in dorsal horn neurons in the adult rat, supposedly by way of their cognate receptors, which are present on these neurons. We further suggest that the endogenous release of GDNF and BDNF, triggered by nociceptive stimuli, is involved in the induction of changes in spinal nociceptive transmission as in various pain states.

High-dose intravenous immunoglobulin therapy for myasthenia gravis

Abstract The objective of this open, retrospective study was to investigate whether intravenous immunoglobulin (IVIg) could induce a clinically obvious improvement in patients with generalized myasthenia gravis (MG), as judged by MG functional status. Fourteen patients with generalized MG were treated during at least one episode with 0.4 g IVIg per kilogram body weight per day for 5 consecutive days. Patients with confounding variables were excluded; this left 11 patients (16 episodes) to be further analysed. We defined improvement as at least a one-step improvement in MG functional status (according to the University of Virginia’s Modification of Osserman’s classification). Of the treatment episodes, 56% were classified as positive responses. If improvement occurred, onset of improvement started after 3 (1–12) days and peak effect was reached after 7 (4– 30) days (median and range). All four patients who required artificial ventilation could be weaned from it 8.5 (6–11) days after the start of IVIg (median and range). Of the patients treated on two occasions, only one patient had a positive response during both. In MG functional status 5, improvement was observed during five of seven episodes. None of the patients with MG functional status 3 responded. Patients with an acute relapse of MG seemed to respond equally well to IVIg compared with patients with subacute deterioration/ chronic-static state (50% versus 60%). The MG functional status at the start of IVIg and on the day of maximal improvement was compared for all episodes together, and significant improvement was noted (P = 0.0052). We did not see any serious side-effects after IVIg treatment. This retrospective analysis suggests that high-dose IVIg is an effective therapy in some patients with deterioration of generalized MG. If improvement occurs, it starts within a few days of the onset of IVIg and the effect seems to peak within 2 weeks.

The evidence for pharmacologic treatment of neuropathic cancer pain: Beneficial and adverse effects

CONTEXT The prevalence of neuropathic pain in patients with cancer pain has been estimated to be around 40%. Neuropathic pain may be caused by tumor invasion and is considered as mixed nociceptive-neuropathic pain, or caused by an anticancer treatment and considered as purely neuropathic pain. The use of adjuvant analgesics in patients with cancer is usually extrapolated from their efficacy in nononcological neuropathic pain syndromes. OBJECTIVES In this systematic review, we sought to evaluate the evidence for the beneficial and adverse effects of pharmacologic treatment of neuropathic cancer pain. METHODS A systematic review of the literature in PubMed and Embase was performed. Primary outcome measures were absolute risk benefit (ARB), defined as the number of patients with a defined degree of pain relief divided by the total number of patients in the treatment group, and absolute risk harm (ARH), defined as the fraction of patients who dropped out as a result of adverse effects. RESULTS We identified 30 articles that fulfilled our inclusion criteria. Overall, ARB of antidepressants, anticonvulsants, other adjuvant analgesics, or opioids greatly outweighed ARH. There were no significant differences in ARB or ARH between the four groups of medication or between patients with mixed vs. purely neuropathic pain. Because of the low methodological quality of the studies, we could not draw conclusions about the true treatment effect size of the four groups of medications. CONCLUSION Once a diagnosis of neuropathic pain has been established in patients with cancer, antidepressants, anticonvulsants, or other adjuvant analgesics should be considered in addition to or instead of opioids.

Distribution of RET immunoreactivity in the rodent spinal cord and changes after nerve injury.

RET (for “rearranged during transfection”) is a transmembrane tyrosine kinase signaling receptor for members of the glial cell line‐derived neurotrophic factor (GDNF) family of ligands. We used RET immunohistochemistry (IHC), double‐labeling immunofluorescence (IF), and in situ hybridization (ISH) in adult naïve and nerve‐injured rats to study the distribution of RET in the spinal cord. In the dorsal horn, strong RET‐immunoreactive (‐ir) fibers were abundant in lamina II‐inner (IIi), although this labeling was preferentially observed after an antigen‐unmasking procedure. After dorsal rhizotomy, RET‐ir fibers in lamina IIi completely disappeared from the dorsal horn, indicating that they were all primary afferents. After peripheral axotomy, RET‐ir in primary afferents decreased in lamina IIi and appeared to increase slightly in laminae III and IV. RET‐ir was also observed in neurons and dendrites throughout the dorsal horn. Some RET‐ir neurons in lamina I had the morphological appearance of nociceptive projection neurons, which was confirmed by the finding that 53% of RET‐ir neurons in lamina I colocalized with neurokinin‐1. GDNF‐ir terminals were in close proximity to RET‐ir neurons in the superficial dorsal horn. In the ventral horn, RET‐ir was strongly expressed by motoneurons, with the strongest staining in small, presumably γ‐motoneurons. Increased RET expression following peripheral axotomy was most pronounced in α‐motoneurons. The expression and regulation pattern of RET in the spinal cord are in line with its involvement in regenerative processes following nerve injury. The presence of RET in dorsal horn neurons, including nociceptive projection neurons, suggests that RET also has a role in signal transduction at the spinal level. This role may include mediating the effects of GDNF released from nociceptive afferent fibers. J. Comp. Neurol. 500:1136–1153, 2007.

General Aspects and Mechanisms of Peripheral Neuropathy Associated With Bortezomib in Patients With Newly Diagnosed Multiple Myeloma

Introduction of the proteasome inhibitor bortezomib (Velcade, Millennium Pharmaceuticals, The Takeda Oncology Company, Cambridge, MA) has substantially improved outcomes for patients with multiple myeloma (MM), and has become one of the cornerstones of current anti-myeloma treatment regimens. However, with the introduction of bortezomib it has become clear that peripheral neuropathy (PN) is one of the most frequent, potentially disabling, nonhematologic complications of bortezomib, often requiring dose modification or discontinuation, with a potential negative impact on clinical endpoints and quality of life. To find a balance between maximal benefit of bortezomib treatment, while maintaining quality of life, it is necessary to minimize toxicity. Here, we discuss all aspects of bortezomib-induced peripheral neuropathy (BiPN), and elaborate on the mechanisms underlying the development of BiPN.