A human brain microphysiological system derived from induced pluripotent stem cells to study neurological diseases and toxicity

Human in vitro models of brain neurophysiology are needed to investigate molecular and cellular mechanisms associated with neurological disorders and neurotoxicity. We have developed a reproducible iPSC-derived human 3D brain microphysiological system (BMPS), comprised of differentiated mature neurons and glial cells (astrocytes and oligodendrocytes) that reproduce neuronal-glial interactions and connectivity. BMPS mature over eight weeks and show the critical elements of neuronal function: synaptogenesis and neuron-to-neuron (e.g., spontaneous electric field potentials) and neuronal-glial interactions (e.g., myelination), which mimic the microenvironment of the central nervous system, rarely seen in vitro before. The BMPS shows 40% overall myelination after 8 weeks of differentiation. Myelin was observed by immunohistochemistry and confirmed by confocal microscopy 3D reconstruction and electron microscopy. These findings are of particular relevance since myelin is crucial for proper neuronal function and development. The ability to assess oligodendroglial function and mechanisms associated with myelination in this BMPS model provide an excellent tool for future studies of neurological disorders such as multiple sclerosis and other demyelinating diseases. The BMPS provides a suitable and reliable model to investigate neuron-neuroglia function as well as pathogenic mechanisms in neurotoxicology.

Guillain-Barré Syndrome Associated with Zika Virus Infection in Colombia

BACKGROUND

Zika virus (ZIKV) infection has been linked to the Guillain-Barré syndrome. From November 2015 through March 2016, clusters of cases of the Guillain-Barré syndrome were observed during the outbreak of ZIKV infection in Colombia. We characterized the clinical features of cases of Guillain-Barré syndrome in the context of this ZIKV infection outbreak and investigated their relationship with ZIKV infection.

METHODS

A total of 68 patients with the Guillain-Barré syndrome at six Colombian hospitals were evaluated clinically, and virologic studies were completed for 42 of the patients. We performed reverse-transcriptase-polymerase-chain-reaction (RT-PCR) assays for ZIKV in blood, cerebrospinal fluid, and urine, as well as antiflavivirus antibody assays.

RESULTS

A total of 66 patients (97%) had symptoms compatible with ZIKV infection before the onset of the Guillain-Barré syndrome. The median period between the onset of symptoms of ZIKV infection and symptoms of the Guillain-Barré syndrome was 7 days (interquartile range, 3 to 10). Among the 68 patients with the Guillain-Barré syndrome, 50% were found to have bilateral facial paralysis on examination. Among 46 patients in whom nerve-conduction studies and electromyography were performed, the results in 36 patients (78%) were consistent with the acute inflammatory demyelinating polyneuropathy subtype of the Guillain-Barré syndrome. Among the 42 patients who had samples tested for ZIKV by RT-PCR, the results were positive in 17 patients (40%). Most of the positive RT-PCR results were in urine samples (in 16 of the 17 patients with positive RT-PCR results), although 3 samples of cerebrospinal fluid were also positive. In 18 of 42 patients (43%) with the Guillain-Barré syndrome who underwent laboratory testing, the presence of ZIKV infection was supported by clinical and immunologic findings. In 20 of these 42 patients (48%), the Guillain-Barré syndrome had a parainfectious onset. All patients tested were negative for dengue virus infection as assessed by RT-PCR.

CONCLUSIONS

The evidence of ZIKV infection documented by RT-PCR among patients with the Guillain-Barré syndrome during the outbreak of ZIKV infection in Colombia lends support to the role of the infection in the development of the Guillain-Barré syndrome. (Funded by the Bart McLean Fund for Neuroimmunology Research and others.).

Zika Virus-Associated Neurological Disease in the Adult: Guillain-Barré Syndrome, Encephalitis, and Myelitis

Zika virus (ZIKV) has caused a major infection outbreak in the Americas since 2015. In parallel with the ZIKV epidemic, an increase in cases of neurological disorders which include Guillain-Barré syndrome (GBS), encephalitis, and myelitis have been linked to the infection. We reviewed the evidence suggesting a relationship between ZIKV and neurological disorders in adults. A search of the literature supporting such link included databases such as PubMed and the World Health Organization (WHO) surveillance system. Through June 1, 2016, 761 publications were available on PubMed using the search word "Zika." Among those publications as well as surveillance reports released by the WHO and other health organizations, 20 articles linked ZIKV with neurological complications other than microcephaly. They corresponded to population and surveillance studies (n = 7), case reports (n = 9), case series (n = 3), and case-control studies (n = 1). Articles were also included if they provided information related to possible mechanisms of ZIKV neuropathogenesis. Evidence based on epidemiological and virological information supports the hypothesis that ZIKV infection is associated with GBS. Although cases of encephalopathy and myelitis have also been linked to ZIKV infection, the evidence is scarce and there is a need for virological, epidemiological, and controlled studies to better characterize such relationship.

Gait Disturbance as the Presenting Symptom in Young Children With Anti-NMDA Receptor Encephalitis

This case series demonstrates a novel clinical phenotype of gait disturbance as an initial symptom in children <3 years old with anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis. Anti-NMDAR encephalitis is one of the most common causes of encephalitis in children, more common than any of the viral encephalitides and the second most common autoimmune cause after acute disseminated encephalomyelitis. Anti-NMDAR encephalitis in children often presents with disrupted speech and sleep patterns followed by progression to motor dysfunction, dyskinesias, and seizures. Because this condition can present initially with vague symptoms, diagnosis and treatment of anti-NMDAR encephalitis are often delayed. Although nearly 40% of all reported patients are <18 years old, few infants and toddlers have been reported with this disease. Four children <3 years old were diagnosed with anti-NMDAR encephalitis at our institution. Interestingly, each child presented initially with the chief concern of gait disturbance. One child presented with unsteady walking and slurred speech, suggestive of cerebellar ataxia, and 3 had inability to bear weight on a unilateral lower extremity, resulting in unsteady gait. Two of these children had seizures at the time of hospital presentation. All developed classic behavioral changes, insomnia, dyskinesias, or decreased speech immediately before or during hospitalization. When seen in the setting of other neurologic abnormalities, gait disturbance should raise the concern for anti-NMDAR encephalitis in young children. The differential diagnosis for gait disturbance in toddlers and key features suggestive of anti-NMDAR encephalitis are reviewed.

Next-generation sequencing in neuropathologic diagnosis of infections of the nervous system

Objective:

To determine the feasibility of next-generation sequencing (NGS) microbiome approaches in the diagnosis of infectious disorders in brain or spinal cord biopsies in patients with suspected CNS infections.

Methods:

In a prospective pilot study, we applied NGS in combination with a new computational analysis pipeline to detect the presence of pathogenic microbes in brain or spinal cord biopsies from 10 patients with neurologic problems indicating possible infection but for whom conventional clinical and microbiology studies yielded negative or inconclusive results.

Results:

Direct DNA and RNA sequencing of brain tissue biopsies generated 8.3 million to 29.1 million sequence reads per sample, which successfully identified with high confidence the infectious agent in 3 patients for whom validation techniques confirmed the pathogens identified by NGS. Although NGS was unable to identify with precision infectious agents in the remaining cases, it contributed to the understanding of neuropathologic processes in 5 others, demonstrating the power of large-scale unbiased sequencing as a novel diagnostic tool. Clinical outcomes were consistent with the findings yielded by NGS on the presence or absence of an infectious pathogenic process in 8 of 10 cases, and were noncontributory in the remaining 2.

Conclusions:

NGS-guided metagenomic studies of brain, spinal cord, or meningeal biopsies offer the possibility for dramatic improvements in our ability to detect (or rule out) a wide range of CNS pathogens, with potential benefits in speed, sensitivity, and cost. NGS-based microbiome approaches present a major new opportunity to investigate the potential role of infectious pathogens in the pathogenesis of neuroinflammatory disorders.

MSPrecise: A molecular diagnostic test for multiple sclerosis using next generation sequencing

BACKGROUND

We have previously demonstrated that cerebrospinal fluid-derived B cells from early relapsing-remitting multiple sclerosis (RRMS) patients that express a VH4 gene accumulate specific replacement mutations. These mutations can be quantified as a score that identifies such patients as having or likely to convert to RRMS. Furthermore, we showed that next generation sequencing is an efficient method for obtaining the sequencing information required by this mutation scoring tool, originally developed using the less clinically viable single-cell Sanger sequencing.

OBJECTIVE

To determine the accuracy of MSPrecise, the diagnostic test that identifies the presence of the RRMS-enriched mutation pattern from patient cerebrospinal fluid B cells.

METHODS

Cerebrospinal fluid cell pellets were obtained from RRMS and other neurological disease (OND) patient cohorts. VH4 gene segments were amplified, sequenced by next generation sequencing and analyzed for mutation score.

RESULTS

The diagnostic test showed a sensitivity of 75% on the RRMS cohort and a specificity of 88% on the OND cohort. The accuracy of the test in identifying RRMS patients or patients that will develop RRMS is 84%.

CONCLUSION

MSPrecise exhibits good performance in identifying patients with RRMS irrespective of time with RRMS.

Systemic Tolerance Mediated by Melanoma Brain Tumors Is Reversible by Radiotherapy and Vaccination

PURPOSE

Immune responses to antigens originating in the central nervous system (CNS) are generally attenuated, as collateral damage can have devastating consequences. The significance of this finding for the efficacy of tumor-targeted immunotherapies is largely unknown.

EXPERIMENTAL DESIGN

The B16 murine melanoma model was used to compare cytotoxic responses against established tumors in the CNS and in the periphery. Cytokine analysis of tissues from brain tumor-bearing mice detected elevated TGFβ secretion from microglia and in the serum and TGFβ signaling blockade reversed tolerance of tumor antigen-directed CD8 T cells. In addition, a treatment regimen using focal radiation therapy and recombinant Listeria monocytogenes was evaluated for immunologic activity and efficacy in this model.

RESULTS

CNS melanomas were more tolerogenic than equivalently progressed tumors outside the CNS as antigen-specific CD8 T cells were deleted and exhibited impaired cytotoxicity. Tumor-bearing mice had elevated serum levels of TGFβ; however, blocking TGFβ signaling with a small-molecule inhibitor or a monoclonal antibody did not improve survival. Conversely, tumor antigen-specific vaccination in combination with focal radiation therapy reversed tolerance and improved survival. This treatment regimen was associated with increased polyfunctionality of CD8 T cells, elevated T effector to T regulatory cell ratios, and decreased TGFβ secretion from microglia.

CONCLUSIONS

These data suggest that CNS tumors may impair systemic antitumor immunity and consequently accelerate cancer progression locally as well as outside the CNS, whereas antitumor immunity may be restored by combining vaccination with radiation therapy. These findings are hypothesis-generating and warrant further study in contemporary melanoma models as well as human trials.

Differentiating neuromyelitis optica from other causes of longitudinally extensive transverse myelitis on spinal magnetic resonance imaging

BACKGROUND

Although spinal magnetic resonance imaging (MRI) findings of neuromyelitis optica (NMO) have been described, there is limited data available that help differentiate NMO from other causes of longitudinally extensive transverse myelitis (LETM).

OBJECTIVE

To investigate the spinal MRI findings of LETM that help differentiate NMO at the acute stage from multiple sclerosis (MS) and other causes of LETM.

METHODS

We enrolled 94 patients with LETM into our study. Bright spotty lesions (BSL), the lesion distribution and location were evaluated on axial T2-weighted images. Brainstem extension, cord expansion, T1 darkness and lesion enhancement were noted. We also reviewed the brain MRI of the patients during LETM.

RESULTS

Patients with NMO had a greater amount of BSL and T1 dark lesions (p < 0.001 and 0.003, respectively). The lesions in NMO patients were more likely to involve greater than one-half of the spinal cord's cross-sectional area; to enhance and be centrally-located, or both centrally- and peripherally-located in the cord. Of the 62 available brain MRIs, 14 of the 27 whom were NMO patients had findings that may be specific to NMO.

CONCLUSIONS

Certain spinal cord MRI features are more commonly seen in NMO patients and so obtaining brain MRI during LETM may support diagnosis.

Re-analysis of metagenomic sequences from acute flaccid myelitis patients reveals alternatives to enterovirus D68 infection

Metagenomic sequence data can be used to detect the presence of infectious viruses and bacteria, but normal microbial flora make this process challenging. We re-analyzed metagenomic RNA sequence data collected during a recent outbreak of acute flaccid myelitis (AFM), caused in some cases by infection with enterovirus D68. We found that among the patients whose symptoms were previously attributed to enterovirus D68, one patient had clear evidence of infection with Haemophilus influenzae, and a second patient had a severe Staphylococcus aureus infection caused by a methicillin-resistant strain. Neither of these bacteria were identified in the original study. These observations may have relevance in cases that present with flaccid paralysis because bacterial infections, co-infections or post-infection immune responses may trigger pathogenic processes that may present as poliomyelitis-like syndromes and may mimic AFM.  A separate finding was that large numbers of human sequences were present in each of the publicly released samples, although the original study reported that human sequences had been removed before deposition.

Gadolinium-based MRI characterization of leptomeningeal inflammation in multiple sclerosis

OBJECTIVE

To determine the frequency and nature of leptomeningeal contrast enhancement in multiple sclerosis (MS) via in vivo 3-tesla postcontrast T2-weighted, fluid-attenuated inversion recovery (FLAIR) MRI and 7-tesla postmortem MRI-pathology correlation.

METHODS

Brain MRI, using the postcontrast T2-weighted, FLAIR technique, was prospectively collected in 299 MS cases and 37 age-matched neurologically healthy controls. Expert raters evaluated focal gadolinium enhancement in the leptomeningeal compartment. Two progressive MS cases came to autopsy after in vivo MRI characterization. Pathologic and immunohistochemical examination assessed the association of enhancement with leptomeningeal inflammation and adjacent cortical demyelination.

RESULTS

Focal contrast enhancement was detected in the leptomeningeal compartment in 74 of 299 MS cases (25%) vs 1 of 37 neurologically healthy controls (2.7%; p = 0.001). Enhancement was nearly twice as frequent (p = 0.009) in progressive MS (39/118 cases, 33%) as in relapsing-remitting MS (35/181, 19%). Enhancing foci generally remained stable throughout the evaluation period (up to 5.5 years). Pathology showed perivascular lymphocytic and mononuclear infiltration in the enhancing areas in association with flanking subpial cortical demyelination.

CONCLUSION

Leptomeningeal contrast enhancement occurs frequently in MS and is a noninvasive, in vivo marker of inflammation and associated subpial demyelination. It might therefore enable testing of new treatments aimed at eliminating this inflammation and potentially arresting progressive MS.

Impact of minocycline on cerebrospinal fluid markers of oxidative stress, neuronal injury, and inflammation in HIV-seropositive individuals with cognitive impairment

Elevated cerebrospinal fluid (CSF) levels of markers of oxidative stress, neuronal injury, and inflammation and decreased neurotransmitter levels have been reported in HIV-associated neurocognitive disorders (HAND). Minocycline may have a neuroprotective effect by inhibiting inducible nitric oxide synthase, which produces nitric oxide, a compound that induces oxygen free radical production. In A5235, "Phase II, Randomized, Placebo-Controlled, Double-Blind Study of Minocycline in the Treatment of HIV-Associated Cognitive Impairment," minocycline was not associated with cognitive improvement, but the effect on the above CSF measures was not examined previously. The objective of this study was to examine the effect of minocycline on markers of oxidative stress, neuronal injury, neurotransmitter levels, and inflammation from CSF in participants in A5235. One hundred seven HIV+ individuals received either minocycline 100 mg or placebo orally every 12 h for 24 weeks. Twenty-one HIV+ individuals received the optional lumbar punctures. Lipid and protein markers of oxidative stress (e.g., ceramides and protein carbonyls), glutamate, neurotransmitter precursors, kynurenine metabolites, neurofilament heavy chain, and inflammatory cytokines were measured in the CSF before and after treatment. The 24-week change in ceramides was larger in a beneficial direction in the minocycline group compared to the placebo group. The two groups did not differ in the 24-week changes for other markers.These results suggest that minocycline may decrease lipid markers of oxidative stress (ceramides) in individuals with HAND; however, an effect of minocycline on other CSF markers was not observed. A larger sample size is needed to further validate these results.

Angiographic suppression of the artery of Adamkiewicz by venous hypertension resolving after embolization in a case of spinal epidural arteriovenous fistula

A case of complete angiographic suppression of the artery of Adamkiewicz and anterior spinal artery in a patient with a spinal epidural arteriovenous fistula (AVF) is reported. Slow flow AVFs typically present with progressive myelopathy secondary to spinal venous hypertension (SVH). The lack of a normal venous phase during angiography and its restoration after treatment is commonly observed with these lesions, yet a similar phenomenon seems exceptional at the arterial level. Right T11 intercostal artery angiograms obtained before and after treatment of a left L4 epidural AVF documented the initial suppression of the artery of Adamkiewicz and anterior spinal artery, and their normal appearance immediately after correction of the SVH by embolization. This report confirms that SVH can angiographically suppress prominent and functionally important spinal arteries, re-emphasizing the potential role played by secondary arterial changes in SVH induced myelopathy. This hemodynamic phenomenon also represents a potential pitfall during diagnostic and therapeutic endovascular procedures.

Quantification of Plasmodium falciparum histidine-rich protein-2 in cerebrospinal spinal fluid from cerebral malaria patients

A cerebrospinal fluid (CSF) biomarker for cerebral malaria (CM) has not been validated. We examined the detection, semiquantification, and clinical use of the Plasmodium falciparum histidine-rich protein-2 (PfHRP-2) as a parasite antigen biomarker for CM. The PfHRP-2 was detected in archival CSF samples from CM patients from Tanzania both by a newly developed sensitive and specific immuno-polymerase chain reaction (72 of 73) and by rapid diagnostic tests (62 of 73). The geometric mean PfHRP-2 CSF concentration was 8.76 ng/mL with no differences in those who survived (9.2 ng/mL), those who died (11.1 ng/mL), and those with neurologic sequelae (10.8 ng/mL). All aparasitemic endemic and nonendemic control samples had undetectable CSF PfHRP-2. In a separate group of 11 matched plasma and CSF cerebral malaria patient samples, the ratio of plasma to CSF PfHRP-2 was 175. The CSF PfHRP-2 reflects elevated plasma PfHRP-2 rather than elevated CM-specific CSF ratios, falling short of a validated biomarker.

Focal compression of the upper left thoracic intersegmental arteries as a potential cause of spinal cord ischemia

BACKGROUND AND PURPOSE

This study was prompted by recurrent angiographic observations of focal stenoses involving the proximal segment of the left upper thoracic intersegmental arteries, a few centimeters distal to their origin. The purpose was to investigate the nature and prevalence of this anomaly.

MATERIALS AND METHODS

The existence of non-ostial thoracic intersegmental artery stenoses was evaluated in 50 angiograms; the contribution of stenosed branches to the anterior spinal artery was recorded. Angiograms performed in 3 patients with right-sided aortas were also reviewed. The topographic relationships of the upper thoracic intersegmental artery with surrounding structures were investigated in 3 cadavers.

RESULTS

Thirty-seven non-ostial stenoses were found in 26 patients (52%), predominantly on the left side (92%), between T3 and T8, most frequently at T4 and T5 (54%). Severe lesions were observed in 10% of cases. Patients with stenoses had fewer detectable anterior radiculomedullary arteries between T3 and T5 (35% versus 54%). Upper intersegmental artery stenoses, documented on the left side of all 3 specimens, appeared to be caused by the recurrent path of these intersegmental arteries related to the leftward position of the thoracic aorta, and by their course around reinforced paramedian longitudinal strands of the endothoracic fascia.

CONCLUSIONS

Upper thoracic intersegmental artery stenoses are frequent. They result from the leftward deviation of the descending aorta and the existence of a fixed point along the course of the intersegmental arteries related to the endothoracic fascia. Because contributors to the spinal vascularization often originate at similar levels, these stenoses may play a role in the susceptibility of the upper and midthoracic spinal cord to ischemia.

Mechanisms of epileptogenesis in pediatric epileptic syndromes: Rasmussen encephalitis, infantile spasms, and febrile infection-related epilepsy syndrome (FIRES)

The mechanisms of epileptogenesis in pediatric epileptic syndromes are diverse, and may involve disturbances of neurodevelopmental trajectories, synaptic homeostasis, and cortical connectivity, which may occur during brain development, early infancy, or childhood. Although genetic or structural/metabolic factors are frequently associated with age-specific epileptic syndromes, such as infantile spasms and West syndrome, other syndromes may be determined by the effect of immunopathogenic mechanisms or energy-dependent processes in response to environmental challenges, such as infections or fever in normally-developed children during early or late childhood. Immune-mediated mechanisms have been suggested in selected pediatric epileptic syndromes in which acute and rapidly progressive encephalopathies preceded by fever and/or infections, such as febrile infection-related epilepsy syndrome, or in chronic progressive encephalopathies, such as Rasmussen encephalitis. A definite involvement of adaptive and innate immune mechanisms driven by cytotoxic CD8(+) T lymphocytes and neuroglial responses has been demonstrated in Rasmussen encephalitis, although the triggering factor of these responses remains unknown. Although the beneficial response to steroids and adrenocorticotropic hormone of infantile spasms, or preceding fever or infection in FIRES, may support a potential role of neuroinflammation as pathogenic factor, no definite demonstration of such involvement has been achieved, and genetic or metabolic factors are suspected. A major challenge for the future is discovering pathogenic mechanisms and etiological factors that facilitate the introduction of novel targets for drug intervention aimed at interfering with the disease mechanisms, therefore providing putative disease-modifying treatments in these pediatric epileptic syndromes.

Rasmussen's encephalitis: clinical features, pathobiology, and treatment advances

Rasmussen's encephalitis is a rare chronic neurological disorder, characterised by unilateral inflammation of the cerebral cortex, drug-resistant epilepsy, and progressive neurological and cognitive deterioration. Neuropathological and immunological studies support the notion that Rasmussen's encephalitis is probably driven by a T-cell response to one or more antigenic epitopes, with potential additional contribution by autoantibodies. Careful analysis of the association between histopathology and clinical presentation suggests that initial damage to the brain is mediated by T cells and microglia, suggesting a window for treatment if Rasmussen's encephalitis can be diagnosed early. Advances in neuroimaging suggest that progression of the inflammatory process seen with MRI might be a good biomarker in Rasmussen's encephalitis. For many patients, families, and doctors, choosing the right time to move from medical management to surgery is a real therapeutic dilemma. Cerebral hemispherectomy remains the only cure for seizures, but there are inevitable functional compromises. Decisions of whether or when surgery should be undertaken are challenging in the absence of a dense neurological deficit, and vary by institutional experience. Further, the optimum time for surgery, to give the best language and cognitive outcome, is not yet well understood. Immunomodulatory treatments seem to slow rather than halt disease progression in Rasmussen's encephalitis, without changing the eventual outcome.

Glycerol rhizotomy and radiofrequency thermocoagulation for trigeminal neuralgia in multiple sclerosis

Object

Patients with trigeminal neuralgia due to multiple sclerosis (TN-MS) and idiopathic TN (ITN) who underwent glycerol rhizotomy (GR) and radiofrequency thermocoagulation with glycerol rhizotomy (RFTC-GR) were compared to investigate the effectiveness of these percutaneous ablative procedures in the TN-MS population.

Methods

Between 1998 and 2010, 822 patients with typical TN were evaluated; 63 (8%) had TN-MS and 759 (92%) had ITN. Pain relief comparisons were made between 22 GR procedures in patients with TN-MS and 470 GR procedures in patients with ITN; 50 RFTC-GR procedures in patients with TN-MS and 287 RFTC-GR procedures in patients with ITN were compared. Analysis of time to recurrence included only procedures that achieved complete pain relief without medications.

Results

After 15 of the GR procedures (68%) in patients with TN-MS and 315 of the procedures (67%) in those with ITN, the patients were pain free without medications (p = 0.736). After 36 of the RFTC-GR procedures (72%) in patients with TN-MS and 210 of the procedures (73%) in those with ITN, the patients were pain free without medications (p = 0.657). The difference in pain relief between GR and RFTC-GR for patients with TN-MS was not significant (p = 0.447). The median time to failure of GR was 20 months in patients with TN-MS compared with 25 months in those with ITN (p = 0.403). The median time to failure of RFTC-GR was 26 months in the TN-MS population compared with 21 months in the ITN population (p = 0.449). Patients with TN-MS experienced similar times to recurrence whether they were treated with GR or RFTC-GR (p = 0.431).

Conclusions

Pain relief and durability of relief outcomes of GR and RFTC-GR were similar in patients with TN-MS and ITN, reinforcing their use as preferred treatments of TN-MS. The GR and RFTC-GR achieved comparable outcomes in patients with TN-MS, suggesting that both can be used to good effect.

Global NeuroAIDS roundtable

In May 2012, the Division of AIDS Research at the National Institute of Mental Health (NIMH) organized the "Global NeuroAIDS Roundtable" in conjunction with the 11th International Symposium on Neurovirology and the 2012 Conference on HIV in the Nervous System. The meeting was held in New York, NY, USA and brought together NIMH-funded investigators who are currently working on projects related to the neurological complications of AIDS (NeuroAIDS) in Africa, Asia, Eastern Europe, and Latin America in order to provide an opportunity to share their recent findings and discuss the challenges encountered within each country. The major goals of the roundtable were to evaluate HIV-associated neurocognitive impairment and determine if it may be directly attributable to distinct HIV subtypes or clades and to discuss the future priorities for global NeuroAIDS research. At the "Global NeuroAIDS Roundtable", presentations of preliminary research indicated that HIV-associated neurocognitive impairment is prevalent in all countries examined regardless of which HIV clade is present in the region. The only clear-cut difference between HIV-1 clades was in relation to subtypes A and D in Uganda. However, a key point that emerged from the discussions was that there is an urgent need to standardize neurocognitive assessment methodologies across the globe before definitive conclusions can be drawn regarding the relationship between HIV clade diversity and neuropathogenesis. Future research directions were also discussed at the roundtable with particular emphasis on the potential of viral and host factor molecular interactions to impact the pathophysiology of HIV-associated neurocognitive disorders (HAND) from a global perspective.

PML-IRIS in a patient treated with brentuximab

A 38-year-old woman was diagnosed with cutaneous anaplastic T-cell lymphoma that proved refractory to methotrexate, bexarotene, denileukin diftitox, interferon γ-1b, interferon α-2b, vorinostat, and pralatrexate. She was therefore started on the newly approved monoclonal anti-CD30 antibody brentuximab vedotin. Treatment with brentuximab 1.8 mg/kg IV every 3 weeks quickly led to disappearance of her cutaneous tumors. The day after her second brentuximab infusion she developed word-finding difficulties and unsteady gait. Due to further neurologic deterioration, she was admitted to an outside hospital. Brain MRI revealed multifocal enhancing white matter lesions throughout bilateral cerebral hemispheres and posterior fossa (figure, A-C). Brain biopsy was performed 15 days after her last brentuximab dose to rule out metastases and she was diagnosed with progressive multifocal leukoencephalopathy (PML) (figure, J). The patient was discharged home with hospice care. Upon discharge, she was started on prednisone 50 mg daily to help treat her eczema. Her family brought her to our clinic for a second opinion.

GH, but not GHRH, plays a role in the development of experimental autoimmune encephalomyelitis

GH has been suggested to influence the function of the immune system in several species. Experimental autoimmune encephalomyelitis (EAE) (an animal model for multiple sclerosis) has been reported not to occur in GH-deficient (GHD) mice. The aim of this study was to elucidate the effects of GH and GHRH replacement on development of EAE in a mouse model of isolated GHD due to removal of the GHRH gene [GHRH knockout (GHRHKO)]. We studied two groups of adult female mice: 12 GH-sufficient animals (control) and 36 GHRHKO animals. All mice were immunized with myelin oligodendrocyte glycoprotein peptide, a peptide known to induce EAE. GHRHKO mice were left untreated or were treated for 4 wk with daily sc injections of recombinant GH or of a GHRH super agonist JI-38 (JI38-GHD). Evaluation of EAE symptoms was carried out daily, and T-proliferative assay and histopathological analysis of the spinal cord were performed. GHRHKO mice were less prone to develop EAE when compared with control mice. GH (but not JI-38) restored the original susceptibility of mice to the disease, despite lack of complete serum IGF-I normalization. GH treatment was also associated with a markedly increase in spleen size and T-cell proliferation specific to myelin oligodendrocyte glycoprotein peptide. GH (but not GHRH) plays an important role in the development of EAE.