Ablation of the carboxy-terminal end of MAMDC2 causes a distinct muscular dystrophy.

The extracellular matrix (ECM) has an important role in the development and maintenance of skeletal muscle, and several muscle diseases are associated with the dysfunction of ECM elements. MAMDC2 is a putative ECM protein and its role in cell proliferation has been investigated in certain cancer types. However, its participation in skeletal muscle physiology has not been previously studied. We describe 17 individuals with an autosomal dominant muscular dystrophy belonging to two unrelated families in which different heterozygous truncating variants in the last exon of MAMDC2 co-segregate correctly with the disease. The radiological aspect of muscle involvement resembles that of COL6 myopathies with fat replacement at the peripheral rim of vastii muscles. In this cohort, a subfascial and peri-tendinous pattern is observed in upper and lower limb muscles. Here we show that MAMDC2 is expressed in adult skeletal muscle and differentiating muscle cells, where it appears to localize to the sarcoplasm and myonuclei. In addition, we show it is secreted by myoblasts and differentiating myotubes into to the extracellular compartment. The last exon encodes a disordered region with a polar residue compositional bias loss of which likely induces a toxic effect of the mutant protein. The precise mechanisms by which the altered MAMDC2 proteins cause disease remains to be determined. MAMDC2 is a skeletal muscle disease-associated protein. Its role in muscle development and ECM-muscle communication remains to be fully elucidated. Screening of the last exon of MAMDC2 should be considered in patients presenting with autosomal dominant muscular dystrophy, particularly in those with a subfascial radiological pattern of muscle involvement.

Autoantibody screening in Guillain-Barré syndrome.

BACKGROUND: Guillain-Barré syndrome (GBS) is an acute inflammatory neuropathy with a heterogeneous presentation. Although some evidences support the role of autoantibodies in its pathogenesis, the target antigens remain unknown in a substantial proportion of GBS patients. The objective of this study is to screen for autoantibodies targeting peripheral nerve components in Guillain-Barré syndrome. METHODS: Autoantibody screening was performed in serum samples from all GBS patients included in the International GBS Outcome study by 11 different Spanish centres. The screening included testing for anti-ganglioside antibodies, anti-nodo/paranodal antibodies, immunocytochemistry on neuroblastoma-derived human motor neurons and murine dorsal root ganglia (DRG) neurons, and immunohistochemistry on monkey peripheral nerve sections. We analysed the staining patterns of patients and controls. The prognostic value of anti-ganglioside antibodies was also analysed. RESULTS: None of the GBS patients (n = 100) reacted against the nodo/paranodal proteins tested, and 61 (61%) were positive for, at least, one anti-ganglioside antibody. GBS sera reacted strongly against DRG neurons more frequently than controls both with IgG (6% vs 0%; p = 0.03) and IgM (11% vs 2.2%; p = 0.02) immunodetection. No differences were observed in the proportion of patients reacting against neuroblastoma-derived human motor neurons. Reactivity against monkey nerve tissue was frequently detected both in patients and controls, but specific patterns were only detected in GBS patients: IgG from 13 (13%) patients reacted strongly against Schwann cells. Finally, we confirmed that IgG anti-GM1 antibodies are associated with poorer outcomes independently of other known prognostic factors. CONCLUSION: Our study confirms that (1) GBS patients display a heterogeneous repertoire of autoantibodies targeting nerve cells and structures; (2) gangliosides are the most frequent antigens in GBS patients and have a prognostic value; (3) further antigen-discovery experiments may elucidate other potential antigens in GBS.

Serum neurofilament light chain predicts long-term prognosis in Guillain-Barré syndrome patients.

OBJECTIVE: To study baseline serum neurofilament light chain (sNfL) levels as a prognostic biomarker in Guillain-Barré syndrome (GBS). METHODS: We measured NfL in serum (98 samples) and cerebrospinal fluid (CSF) (24 samples) of patients with GBS prospectively included in the International GBS Outcome Study (IGOS) in Spain using single-molecule array (SiMoA) and compared them with 53 healthy controls (HCs). We performed multivariable regression to analyse the association between sNfL levels and functional outcome at 1 year. RESULTS: Patients with GBS had higher NfL levels than HC in serum (55.49 pg/mL vs 9.83 pg/mL, p<0.0001) and CSF (1308.5 pg/mL vs 440.24 pg/mL, p=0.034). Patients with preceding diarrhoea had higher sNfL than patients with respiratory symptoms or no preceding infection (134.90 pg/mL vs 47.86 pg/mL vs 38.02 pg/mL, p=0.016). sNfL levels correlated with Guillain-Barré Syndrome Disability Score and Inflammatory Rasch-built Overall Disability Scale (I-RODS) at every timepoint. Patients with pure motor variant and Miller Fisher syndrome showed higher sNfL levels than patients with sensorimotor GBS (162.18 pg/mL vs 95.50 pg/mL vs 38.02 pg/mL, p=0.025). Patients with acute motor axonal neuropathy cute motor axonal neuropathy had higher sNfL levels than other variants (190.55 pg/mL vs 46.79 pg/mL, p=0.013). sNfL returned to normal levels at 1 year. High baseline sNfL levels were associated with inability to run (OR=1.65, 95% CI 1.14 to 2.40, p=0.009) and lower I-RODS (ß -2.60, 95% CI -4.66 to -0.54, p=0.014) at 1 year. Cut-off points predicting clinically relevant outcomes at 1 year with high specificity were calculated: inability to walk independently (>319 pg/mL), inability to run (>248 pg/mL) and ability to run (<34 pg/mL). CONCLUSION: Baseline sNfL levels are increased in patients with GBS, are associated with disease severity and axonal variants and have an independent prognostic value in patients with GBS.

Study of the effect of anti-rhGAA antibodies at low and intermediate titers in late onset Pompe patients treated with ERT.

Late onset Pompe disease (LOPD) is a genetic disorder characterized by slowly progressive skeletal and respiratory muscle weakness. Symptomatic patients are treated with enzyme replacement therapy (ERT) with alglucosidase alpha (rhGAA). Although most of ERT treated patients develop antibodies against rhGAA, their influence on clinical progression is not completely known. We studied the impact of anti-rhGAA antibodies on clinical progression of 25 ERT treated patients. We evaluated patients at visit 0 and, after 1 year, at visit 1. We performed several muscle function tests, conventional spirometry and quantitative muscle MRI (qMRI) using 3-point Dixon analysis of thigh muscles at both visits. We also obtained serum samples at both visits and anti-rhGAA antibodies were quantified using ELISA. Antibody titers higher than 1:200 were identified in 18 patients (72%) of our cohort. Seven patients (28%) did not develop antibodies (0 to <1:200), 17 patients (68%) developed low to intermediate titers (1:200 to <1:31,200) and 1 patient (4%) developed high titers (>1:31,200). We analyzed the effect of low and intermediate antibody titers in clinical and radiological progression. There were no differences between the results of muscle function tests, spirometry or fat fraction analyzed using qMRI between patients with and without antibodies groups at baseline. Moreover, antibody titers did not influence muscle function test, spirometry results or qMRI results at year 1 visit. Most of the LOPD patients developed antibodies against ERT that persisted over time at low or intermediate levels. However, antibodies at these low and intermediate titers might not influence clinical response to the drug.

Patterns of care and outcome for patients with glioblastoma diagnosed during 2008-2010 in Spain.

BACKGROUND: To assess management patterns and outcome in patients with glioblastoma multiforme (GBM) treated during 2008-2010 in Spain. METHODS: Retrospective analysis of clinical, therapeutic, and survival data collected through filled questionnaires from patients with histologically confirmed GBM diagnosed in 19 Spanish hospitals. RESULTS: We identified 834 patients (23% aged >70 years). Surgical resection was achieved in 66% of patients, although the extent of surgery was confirmed by postoperative MRI in only 41%. There were major postoperative complications in 14% of patients, and age was the only independent predictor (Odds ratio [OR], 1.03; 95% confidence interval [CI],1.01-1.05; P = .006). After surgery, 57% received radiotherapy (RT) with concomitant and adjuvant temozolomide, 21% received other regimens, and 22% were not further treated. In patients treated with surgical resection, RT, and chemotherapy (n = 396), initiation of RT ≤42 days was associated with longer progression-free survival (hazard ratio [HR], 0.8; 95% CI, 0.64-0.99; P = .042) but not with overall survival (HR, 0.79; 95% CI, 0.62-1.00; P = .055). Only 32% of patients older than 70 years received RT with concomitant and adjuvant temozolomide. The median survival in this group was 10.8 months (95% CI, 6.8-14.9 months), compared with 17.0 months (95% CI, 15.5-18.4 months; P = .034) among younger patients with GBM treated with the same regimen. CONCLUSIONS: In a community setting, 57% of all patients with GBM and only 32% of older patients received RT with concomitant and adjuvant temozolomide. In patients with surgical resection who were eligible for chemoradiation, initiation of RT ≤42 days was associated with better progression-free survival.

Human epidermal growth factor receptor 2 overexpression in breast cancer of patients with anti-Yo--associated paraneoplastic cerebellar degeneration.

Isolated case reports suggest that breast tumors from patients with paraneoplastic cerebellar degeneration (PCD) and Yo antibodies overexpress human epidermal growth factor receptor 2 (HER2). HER2 overexpression is present in 15%-25% of breast cancers and is associated with poor prognosis. We retrospectively analyzed the status of HER2 in breast tumors of 27 patients with anti-Yo-associated PCD to evaluate whether HER2 overexpression in this group of patients is higher than expected. In addition, we analyzed HER2 status of 19 breast tumors from patients with paraneoplastic neurological syndromes and Ri antibodies to see whether HER2 was specifically related to anti-Yo-associated PCD. We also assessed cdr2 expression (the onconeural antigen recognized by Yo antibodies) in 21 HER2-positive breast tumors from patients without paraneoplastic neurological syndromes. HER2 was overexpressed in 26 patients (96.3%) with anti-Yo-associated PCD but only in 2 patients (10.5%) with paraneoplastic neurological syndromes associated with Ri antibodies (P< .0001). Only 5 (23.8%) of the 21 HER2-positive breast tumors showed cdr2 immunoreactivity. This study shows a very high frequency of HER2 overexpression in breast cancers in patients with anti-Yo-associated PCD but not in those from patients with Ri antibodies. Although the expression of cdr2 onconeural antigen is not high in HER2-positive breast cancers, HER2 overexpression seems to be an important requirement to develop an anti-Yo-associated PCD.

Hypersomnia as presenting symptom of anti-Ma2-associated encephalitis: case study.

We describe a patient who presented with excessive daytime sleepiness (EDS) and was eventually diagnosed with anti-Ma2 encephalitis. Neurological examination disclosed somnolence, left palpebral ptosis, and vertical gaze paresis. A brain MRI showed high signal intensity in the hypothalamus and each hippocampus. Ma2 antibodies were found in the patient's serum, and fiberbronchoscopy disclosed a lung carcinoma. After three months of steroid treatment, the results of the patient's neurological exam became normal. We conclude that anti-Ma2 encephalitis may present with mostly isolated EDS and that it may respond to steroids despite old age and the presence of an untreated lung cancer.

Frequent hypermethylation of the DNA repair gene MGMT in long-term survivors of glioblastoma multiforme.

We have performed a methylation-specific PCR approach to comparatively analyze the MGMT promoter methylation status in 186 glioblastomas (GBM) from patients with classic survival and nine from patients with long-term survival (LTS GBM). The methylation rate in LTS GBM was significantly higher (77.8% vs. 39.2%, P = 0.033) which suggests that MGMT hypermethylation is a frequent hallmark of LTS GBM and contributes to characterize this intriguing GBM subtype.

Meningeal lymphomatosis as the first manifestation of splenic marginal zone lymphoma.

Meningeal lymphomatosis (ML) as the first manifestation of a splenic marginal zone lymphoma (SMZL) is rare. The descriptions of only 2 cases with this complication, one of which had ML as the first manifestation, have been published to date. We describe a 53-year-old man, an ex-smoker, who presented with transitory episodes of bilateral loss of visual acuity. On examination, only papilledema and splenomegalia were observed. The hemogram showed a predominance of lymphocytes with a villous morphology. Cytochemical staining and an immunophenotypic analysis revealed a positive reaction to tartrate-sensitive acid phosphatase and B-lineage markers (CD19+, CD20+, CD79b+, surface immunoglobulin 3 expression, immunoglobulin D+, CD5-, CD23-, CD10-, CD25-, CD103-, and CD11c-). Magnetic resonance imaging of the brain showed tumoral infiltration in both optic nerves and in the cervicodorsal meninges. The cerebrospinal fluid examination revealed significant pleocytosis, and all lymphocytes had a phenotype identical to that of the peripheral blood, confirming the presence of ML. The bone marrow section also showed lymphocytes with an immunophenotype identical to that of the peripheral blood.A splenectomy confirmed the SMZL diagnosis. Treatment with corticosteroids and intrathecal chemotherapy was administrated; however, the response was not good, and the patient died. In this report, we discuss the other 2 cases and ML in B-cell chronic lymphoproliferative disorders.

CpG island hypermethylation of the DNA repair enzyme methyltransferase predicts response to temozolomide in primary gliomas.

PURPOSE: The DNA repair enzyme O(6)-methylguanine DNA methyltransferase (MGMT) inhibits the killing of tumor cells by alkylating agents, and its loss in cancer cells is associated with hypermethylation of the MGMT CpG island. Thus, methylation of MGMT has been correlated with the clinical response to 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) in primary gliomas. Here, we investigate whether the presence of MGMT methylation in gliomas is also a good predictor of response to another emergent alkylating agent, temozolomide. EXPERIMENTAL DESIGN: Using a methylation-specific PCR approach, we assessed the methylation status of the CpG island of MGMT in 92 glioma patients who received temozolomide as first-line chemotherapy or as treatment for relapses. RESULTS: Methylation of the MGMT promoter positively correlated with the clinical response in the glioma patients receiving temozolomide as first-line chemotherapy (n = 40). Eight of 12 patients with MGMT-methylated tumors (66.7%) had a partial or complete response, compared with 7 of 28 patients with unmethylated tumors (25.0%; P = 0.030). We also found a positive association between MGMT methylation and clinical response in those patients receiving BCNU (n = 35, P = 0.041) or procarbazine/1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (n = 17, P = 0.043) as first-line chemotherapy. Overall, if we analyze the clinical response of all of the first-line chemotherapy treatments with temozolomide, BCNU, and procarbazine/1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea as a group in relation to the MGMT methylation status, MGMT hypermethylation was strongly associated with the presence of partial or complete clinical response (P < 0.001). Finally, the MGMT methylation status determined in the initial glioma tumor did not correlate with the clinical response to temozolomide when this drug was administered as treatment for relapses (P = 0.729). CONCLUSIONS: MGMT methylation predicts the clinical response of primary gliomas to first-line chemotherapy with the alkylating agent temozolomide. These results may open up possibilities for more customized treatments of human brain tumors.

Meningeal carcinomatosis as the first manifestation of a transitional cell carcinoma of the bladder.

Meningeal carcinomatosis (MC) as first manifestation of a transitional cell carcinoma (TCC) of the bladder is rare. We report a 66-year-old man, smoker, who presented with two episodes of secondarily generalized partial motor seizures. The routine blood test, brain computed tomography (CT) scan, brain magnetic resonance imaging and electroencephalogram were normal. Cerebral spinal fluid (CSF) revealed a significant pleocytosis and a morphology compatible with non-differentiated non-small cell carcinoma. Broncofiberscopy, gastrofiberscopy, thoracicoabdominopelvic CT-scan and bone scintigraphy were normal but the urine cytology revealed malignant cells similar to those found in the CSF. TCC was diagnosed by cystoscopy and later necropsy confirmed the MC of this tumor. In this report we review the literature and analyze patient survival.

Spectrum of paraneoplastic neurologic disorders in women with breast and gynecologic cancer.

We conducted the current review of the paraneoplastic neurologic syndromes (PNSs) associated with gynecologic and breast carcinomas to describe their clinical and immunologic characteristics and their relative frequency. We retrospectively reviewed 92 patients whose serum was sent to our laboratories to detect onconeural antibodies and who were diagnosed as having PNSs associated with breast or gynecologic tumors. PNSs were defined as "definitive" and "possible" (atypical PNS, no onconeural antibodies, and no improvement after tumor treatment). Forty-nine patients had breast and 43 had gynecologic cancer. Sixty-three patients had onconeural antibodies (50 Yo-ab, 5 Hu-ab, 5 Ri-ab, and 3 amphiphysin-ab). Cerebellar ataxia represented 57 (62%) of all PNSs and was associated with anti-Yo in 88%. All Yo-abnegative patients had breast cancer; 4 of them had a mild cerebellar syndrome that improved after tumor treatment. Sensorypredominant neuropathies were present in 17 (18%) patients. Seven of them had Hu-ab (5) or amphiphysin-ab (2). Other PNSs were opsoclonus-myoclonus syndrome (4 cases, Ri-ab in 2), sensorimotor neuropathy (4 cases), paraneoplastic encephalomyelitis (4 cases, Ri-ab in 3), paraneoplastic retinopathy (2 cases), amyotrophic lateral sclerosis (2 cases), stiff-person syndrome (1 with amphiphysin-ab), and limbic encephalitis (1 case). All patients with gynecologic cancer presented definitive PNS, and onconeural antibodies were diagnosed in 93% of them. In contrast, 20% of PNSs associated with breast cancer were defined as possible and the incidence of onconeural antibodies was 51%, excluding the 2 patients with paraneoplastic retinopathy in whom antiretinal antibodies were not analyzed. In patients with possible PNS, a coincidental association between the tumor and the neurologic disorder cannot be excluded.