Clinical characteristics and pathophysiological properties of newly discovered LRRK2 variants associated with Parkinson's disease.

Leucine-rich repeat kinase 2 (LRRK2) is the most common gene responsible for familial Parkinson's disease (PD). The gene product of LRRK2 contains multiple protein domains, including armadillo repeat, ankyrin repeat, leucine-rich repeat (LRR), Ras-of-complex (ROC), C-terminal of ROC (COR), kinase, and WD40 domains. In this study, we performed genetic screening of LRRK2 in our PD cohort, detecting sixteen LRRK2 rare variants. Among them, we selected seven variants that are likely to be familial and characterized them in terms of LRRK2 protein function, along with clinical information and one pathological analysis. The seven variants were S1120P and N1221K in the LRR domain; I1339M, S1403R, and V1447M in the ROC domain; and I1658F and D1873H in the COR domain. The kinase activity of the LRRK2 variants N1221K, S1403R, V1447M, and I1658F toward Rab10, a well-known phosphorylation substrate, was higher than that of wild-type LRRK2. LRRK2 D1873H showed enhanced self-association activity, whereas LRRK2 S1403R and D1873H showed reduced microtubule-binding activity. Pathological analysis of a patient with the LRRK2 V1447M variant was also performed, which revealed Lewy pathology in the brainstem. No functional alterations in terms of kinase activity, self-association activity, and microtubule-binding activity were detected in LRRK2 S1120P and I1339M variants. However, the patient with PD carrying LRRK2 S1120P variant also had a heterozygous Glucosylceramidase beta 1 (GBA1) L444P variant. In conclusion, we characterized seven LRRK2 variants potentially associated with PD. Five of the seven variants in different LRRK2 domains exhibited altered properties in kinase activity, self-association, and microtubule-binding activity, suggesting that each domain variant may contribute to disease progression in different ways.

[Guillain-Barré syndrome].

Guillain-Barré syndrome (GBS), an acute immune-mediated neuropathy, occurs following immunological stimulation, such as infection, with complement-mediated neuropathy implicated in the pathophysiology of this condition. Glycolipid antibodies produced by molecular mimicry are detected in approximately 60% of cases. Recent studies have suggested the role of cell-mediated immunity in the pathogenesis of GBS. Intravenous immunoglobulin and plasma exchange are established immunotherapies. In this article, based on the latest knowledge, we describe the pathophysiology, diagnosis, treatment, prognosis, and prognostic prediction of GBS. Furthermore, we discuss some GBS guidelines published by the European Academy of Neurology/Peripheral Nerve Society.

Impact of Istradefylline on Levodopa Dose Escalation in Parkinson's Disease: ISTRA ADJUST PD Study, a Multicenter, Open-Label, Randomized, Parallel-Group Controlled Study.

INTRODUCTION: A higher levodopa dose is a risk factor for motor complications in Parkinson's disease (PD). Istradefylline (IST) is used as adjunctive treatment to levodopa in PD patients with off episodes, but its impact on levodopa dose titration remains unclear. The objective of this study was to investigate the effect of IST on levodopa dose escalation in PD patients with wearing-off. METHODS: This was a multicenter, open-label, randomized, parallel-group controlled study (ISTRA ADJUST PD) in which PD patients experiencing wearing-off (n = 114) who were receiving levodopa 300-400 mg/day were randomized to receive IST or no IST (control). Levodopa dose was escalated according to clinical severity. The primary endpoint was cumulative additional levodopa dose, and secondary endpoints were changes in symptom rating scales, motor activity determined by a wearable device, and safety outcomes. RESULTS: The cumulative additional levodopa dose throughout 37 weeks and dose increase over 36 weeks were significantly lower in the IST group than in the control group (both p < 0.0001). The Movement Disorder Society Unified Parkinson's Disease Rating Scale Part I and device-evaluated motor activities improved significantly from baseline to 36 weeks in the IST group only (all p < 0.05). Other secondary endpoints were comparable between the groups. Adverse drug reactions (ADRs) occurred in 28.8% and 13.2% of patients in the IST and control groups, respectively, with no serious ADRs in either group. CONCLUSION: IST treatment reduced levodopa dose escalation in PD patients, resulting in less cumulative levodopa use. Adjunctive IST may improve motor function more objectively than increased levodopa dose in patients with PD. TRIAL REGISTRATION: Japan Registry of Clinical Trials: jRCTs031180248.

Guillain-Barré Syndrome Mimicking Lumbar Spinal Stenosis with Segmental Weakness in L5-S1 Myotomes: Two Case Reports.

We herein report two cases of Guillain-Barré syndrome (GBS) mimicking lumbar spinal stenosis (LSS). Both cases were initially diagnosed as LSS based on prominent segmental weakness in the L5 and S1 myotomes and coexisting LSS on magnetic resonance imaging. However, neurological and electrophysiological examinations revealed abnormalities that extended to the upper extremities, although slight, prompting us to suspect GBS. Subsequently, serum antiganglioside antibodies and remarkable responsiveness to intravenous immunoglobulin therapy confirmed GBS. We suspect that the focal blood-nerve barrier disruption due to preexisting LSS might have contributed to the segmental weakness in this atypical GBS case.

[Epstein-Barr virus-associated subacute sensorimotor neuropathy with multiple cerebellar microbleeding: a case report].

We report the case of an 82-year-old male with subacute sensorimotor neuropathy associated with Epstein-Barr virus (EBV) infection, who presented with diplopia followed by gait disturbance due to limb weakness. Pathological findings of a biopsied cervical lymph node showed a high frequency of EBV-positive cells. EBV-DNA was detected in blood. A nerve conduction study suggested a mixture of axonal damage and demyelination. Brain MRI showed multiple microbleeds in cerebellar cortices, but cerebrospinal fluid EBV-PCR was negative, suggesting bleeding due to EBV-related vasculitis. Corticosteroid therapy improved the neurological symptoms and the patient was able to walk independently four months later. The main pathogenesis of the neuropathy in this case is likely to be a mixture of vasculitic neuropathy and immune-mediated demyelinating neuropathy, which are considered to be due to EBV reactivation.

[CIDP Refractory to Three Types of Mainstay Treatments: Appropriate Induction Therapy and Evaluation of Therapeutic Effect].

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a disease with a heterogeneous pathology. The responsiveness to mainstay treatment differs depending on the type of CIDP. The treatment strategy is determined based on the type of CIDP, characteristics of the therapeutic agents and treatment methods, and patient background. For CIDPs that do not respond to the mainstay treatment, it is necessary to review whether the induction treatment was properly performed and whether the therapeutic effect was properly evaluated using objective indicators. In particular, treatment-resistant multifocal CIDP and distal CIDP require careful differential diagnoses. Intervention trials using rituximab and anti-neonatal Fcγ receptor monoclonal antibodies are underway, and it is expected that clear treatment guidelines will soon be developed for refractory CIDP.

[A case of recurrent headache and ophthalmoplegia with a contrast-enhanced lesion of the oculomotor nerve in the cavernous region: an atypical phenotype of recurrent painful ophthalmoplegic neuropathy].

The patient was a 14-year-old boy with two previous episodes of self-remitting right ophthalmoplegia with right temporal pain at ages 9 and 12. In 2019, he developed right eyelid ptosis and diplopia 2 days after a pulsating right-sided temporoparietal headache. Recurrent headaches with ophthalmoplegia responded to high-dose steroid therapy, and the clinical features resembled recurrent painful ophthalmoplegic neuropathy (RPON). RPON generally presents with MRI findings of hypertrophy and inflammation at the root of the oculomotor nerve, a vulnerable site of the blood-brain barrier. However, the imaging features in this case were different from those in typical cases of RPON, and oculomotor nerve inflammation was found in the cavernous sinus. The order of onset of headache and oculomotor nerve palsy differed in each recurrence, suggesting that both autoimmune and vascular mechanisms may have been involved in the onset of the disease in our case.

An Atypical Phenotype of Chronic Inflammatory Demyelinating Polyradiculoneuropathy Associated with Ocular Palsy, IgM-anti Ganglioside Antibody, and Fever-induced Recurrence.

We herein report a case of recurrent multifocal, distal-dominant-sensorimotor neuropathy with ophthalmoplegia, IgM anti-GM1 antibody, and pyrexia-associated relapse. The patient developed sensory disturbance in her limbs after febrile disease at 50 years old. She had experienced several similar episodes and was admitted to the hospital at 56 years old. Based on a pathological study and electrophysiological findings consistent with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), maintenance IVIg therapy was administered and produced partial improvement with no relapse at one-year follow-up. Immunohistochemical studies suggested the presence of IgG (not IgM) anti-myelin antibodies. Chronic neuropathy with ophthalmoplegia and pyrexia-associated relapse may be a unique variant of CIDP.

Morphological characterization of cholinergic partition cells: A transmitter-specific tracing study by Cre/lox-dependent viral gene expression.

BACKGROUND: Partition cells are cholinergic interneurons located in lamina VII of the spinal cord. Some partition cells are the source of the cholinergic boutons, known as C-terminals or C-boutons, that modulate the activity of spinal motor neurons. Therefore, partition cells might play an important role in motor control. Previous studies categorized partition cells into three groups (medial, intermediate, and lateral partition cells) according to their distance from the central canal. However, the morphological characteristics of the three groups remain obscure. METHODS: To analyze the morphology of partition cells, we developed an efficient technique for visualization of specific neurons at single-cell level in particular positions using adenovirus vectors and Cre/lox mediated recombination. Cre/lox conditional vectors were injected into the spinal cord of choline acetyltransferase-Cre transgenic mice, and partition cells labeled by green fluorescent protein were reconstructed from histological serial sections at the single-cell level. RESULTS: This technique allowed for the visualization of partition cells at high resolution and revealed that partition cells had various patterns of dendrite orientations and fields. Most of the visualized partition cells had more than 60% of their dendrites located in lamina VII of the spinal cord. Partition cells had dendrites extending into various Rexed's laminae (V, VI, VII, VIII, IX, and X), but none of the cells had dendrites extending dorsal to lamina IV. The dendrites of partition cells terminated both ipsilaterally and bilaterally. We also found that C-terminals on motor neurons may be derived from the middle/outer group of partition cells. CONCLUSIONS: Our results indicated that partition cells have various morphological features of the dendritic pattern and may receive differential inputs. Our results suggested that C-terminals originate not only from medial but also from intermediate/lateral cholinergic partition cells. The present study suggests that intermediate/lateral partition cells modulate activities of motor neurons through C-terminal synapses.

[Treatment Options for Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP): With a Focus on Immunoglobulin Treatment].

The disease state and clinical course of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) are diverse, and the response to treatment varies from patient to patient. Therefore, it is necessary to select a treatment and determine the appropriate dose and dosage interval while monitoring the clinical course after treatment initiation. In this article, we will discuss points to be considered and the results of studies that can be used as references in order to make an appropriate choice at each stage of CIDP treatment.

Thymoma and Autoimmune Encephalitis: Clinical Manifestations and Antibodies.

OBJECTIVE: To report the clinical, neuroimaging, and antibody associations in patients with autoimmune encephalitis (AE) and thymoma. METHODS: A retrospective cohort study of 43 patients was conducted. Antibody determination and immunoprecipitation to characterize novel antigens were performed using reported techniques. RESULTS: Patients' median age was 52 years (range: 23-88 years). Forty (93%) had neuronal surface antibodies: gamma-aminobutyric acid receptor A (GABAAR) (15), amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) (13), contactin-associated protein-like 2 (CASPR2) (4), leucine-rich, glioma inactivated 1 (LGI1) (3), glycine receptor (GlyR) (3), and unknown antigens (2). Concurrent antibodies against intracellular antigens occurred in 13 (30%; 9 anti-collapsin response mediator protein 5 [CRMP5]) and were more frequent in anti-AMPAR encephalitis (54% vs 20%; p = 0.037). The most common clinical presentation was encephalitis with multiple T2/fluid-attenuated inversion recovery hyperintense lesions in 23 (53%) patients (15 GABAAR, 5 AMPAR, and 1 unknown neuropil antibody), followed by encephalitis with peripheral nerve hyperexcitability in 7 (16%; 4 CASPR2, 2 LGI1, and 1 unknown antibody), limbic encephalitis in 6 (14%; 4 AMPAR, 1 LGI1, and 1 antibody negative), progressive encephalomyelitis with rigidity and myoclonus in 4 (9%; 3 GlyR and 1 AMPAR antibodies), and encephalitis with normal MRI in 3 (7%; AMPAR antibodies). Anti-GABAAR encephalitis was more prevalent in Japanese patients compared with Caucasians and other ethnicities (61% vs 16%; p = 0.003). In anti-AMPAR encephalitis, 3/4 patients with poor and 0/6 with good outcome had concurrent CRMP5 antibodies (p = 0.033). Immunoprecipitation studies identified metabotropic glutamate receptor 3 antibodies that were additionally found in 5 patients (3 with and 2 without encephalitis). CONCLUSIONS: AE in patients with thymoma include several clinical-radiologic syndromes that vary according to the associated antibodies. Anti-GABAAR encephalitis was the most frequent AE and occurred more frequently in Japanese patients.

Cholesterol-added antigens can enhance antiglycolipid antibody activity: Application to antibody testing.

We analysed the effect of adding cholesterol to glycolipid antigens on antibody activity with enzyme-linked immunosorbent assay in 123 subjects consisting of 96 patients with Guillain-Barré syndrome, 25 Miller Fisher syndrome, and two Bickerstaff brainstem encephalitis. The use of cholesterol-added GM1 antigens increased anti-GM1 activity in 11 out of 23 anti-GM1-positive patients and resulted in six out of 100 anti-GM1-negative patients becoming anti-GM1-positive. Enhancement of anti-GM1 activity by cholesterol addition was significantly associated with antecedent gastrointestinal infection. The use of cholesterol-added glycolipid antigens can increase the detection rate of anti-glycolipid antibodies and accurately evaluate the anti-glycolipid antibody activity in vivo.

Guillain-Barré syndrome after COVID-19 in Japan.

We report the first case of Guillain-Barré syndrome (GBS) associated with SARS-CoV-2 infection in Japan. A 54-year-old woman developed neurological symptoms after SARS-CoV-2 infection. We tested for various antiganglioside antibodies, that had not been investigated in previous cases. The patient was diagnosed with GBS based on neurological and electrophysiological findings; no antiganglioside antibodies were detected. In previous reports, most patients with SARS-CoV-2-infection-related GBS had lower limb predominant symptoms, and antiganglioside antibody tests were negative. Our findings support the notion that non-immune abnormalities such as hyperinflammation following cytokine storms and microvascular disorders due to vascular endothelial damage may lead to neurological symptoms in patients with SARS-CoV-2 infection. Our case further highlights the need for careful diagnosis in suspected cases of GBS associated with SARS-CoV-2 infection.

Serum IgG anti-GD1a antibody and mEGOS predict outcome in Guillain-Barré syndrome.

OBJECTIVE: Approximately 15%-20% of patients with Guillain-Barré syndrome (GBS) are unable to walk independently at 6 months from the onset of neurological symptom. The modified Erasmus GBS outcome score (mEGOS) has been reported as a prognostic tool.Herein we investigated the association between a poor outcome, inability to walk independently at 6 months and presence of antiganglioside antibodies. METHODS: The clinical and serological data of 177 patients with GBS were retrospectively collected in Japan to assess the associations between a poor outcome and serum IgG antibodies against each ganglioside (GM1, GD1a, GalNAc-GD1a, GQ1b and GT1a). In addition, we investigated whether the combination of mEGOS and serum IgG antibodies against gangliosides is useful in predicting a poor outcome. RESULTS: The patients with IgG anti-GD1a antibodies more frequently showed poor outcomes than those without these antibodies (9 (36%) of 25 vs 8 (6%) of 127 patients, p<0.001). Particularly, 80% showed a poor outcome when they had both serum IgG anti-GD1a antibody and a high mEGOS of ≥10 on day 7 of admission. CONCLUSIONS: The combination of serum IgG anti-GD1a antibodies and a high mEGOS could help in making a more accurate prognosis of patients than mEGOS alone, especially for predicting poor outcomes.

Efficacy and Safety of Rituximab in Refractory CIDP With or Without IgG4 Autoantibodies (RECIPE): Protocol for a Double-Blind, Randomized, Placebo-Controlled Clinical Trial.

BACKGROUND: Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an immune-mediated peripheral neuropathy that is currently classified into several clinical subtypes, which are presumed to have different pathogenic mechanisms. Recently, studies identified a subgroup of patients with CIDP who were positive for IgG4 autoantibodies against paranodal proteins, such as neurofascin-155 and contactin-1, who respond poorly to first-line therapies for typical CIDP, including intravenous immunoglobulin therapy. OBJECTIVE: This study aims to evaluate the efficacy and safety of intravenous rituximab according to IgG4 autoantibody status in patients with refractory CIDP. METHODS: The Evaluation of the Efficacy and Safety of Rituximab in Refractory CIDP Patients with IgG4 Autoantibodies in the Exploratory Clinical (RECIPE) trial consists of 2 cohorts: a multicenter, placebo-controlled, randomized study cohort of 15 patients with IgG4 autoantibody-positive CIDP (rituximab:placebo = 2:1) and an open-label trial cohort of 10 patients with antibody-negative CIDP. The primary endpoint is improvement in functional outcome assessed using the adjusted Inflammatory Neuropathy Cause and Treatment Disability Scale score at 26, 38, or 52 weeks after the start of treatment with rituximab in patients with CIDP and anti-paranodal protein antibodies. Secondary outcome measures include grip strength, manual muscle testing sum scores, results of nerve conduction studies, and other functional scales. RESULTS: We plan to enroll 25 cases for the full analysis set. Recruitment is ongoing, with 14 patients enrolled as of January 2020. Enrollment will close in September 2020, and the study is planned to end in December 2021. CONCLUSIONS: This randomized controlled trial will determine if rituximab is safe and effective in patients with anti-paranodal antibodies. An open-label study will provide additional data on the effects of rituximab in patients with antibody-negative CIDP. The results of the RECIPE trial are expected to provide evidence for the positioning of rituximab as a pathogenesis-based therapeutic for refractory CIDP. TRIAL REGISTRATION: ClinicalTrials.gov NCT03864185, https://clinicaltrials.gov/ct2/show/NCT03864185 ; The Japan Registry of Clinical Trials jRCT2041180037, https://jrct.niph.go.jp/en-latest-detail/jRCT2041180037. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/17117.

Association of variability in antibody binding affinity with a clinical course of anti-MAG neuropathy.

Anti-myelin-associated glycoprotein (MAG) neuropathy is mediated by the binding of IgM M-proteins to the human natural killer-1 epitope of several glycoconjugates, including MAG and phosphacan. We recently reported that IgM M-proteins with a higher ratio of anti-phosphacan titer to anti-MAG titer (P/M ratio) were associated with a progressive clinical course. Herein, we investigated the temporal variability of the P/M ratio. The results showed that P/M ratios in worsened cases were significantly increased relative to stable or improved cases. Thus, temporal variability in the specificity of IgM M-proteins may be related to the disease course of anti-MAG neuropathy.

Unique HLA haplotype associations in IgG4 anti-neurofascin 155 antibody-positive chronic inflammatory demyelinating polyneuropathy.

To clarify the immunogenetic background of patients with immunoglobulin G (IgG)4 anti-neurofascin 155 (NF155) antibody-positive chronic inflammatory demyelinating polyneuropathy (CIDP), we genotyped the extended human leukocyte antigen (HLA) haplotypes in 22 Japanese patients with this disorder and compared them with those of healthy Japanese controls. All IgG4 anti-NF155 antibody-positive CIDP patients exclusively carried either HLA-DRB1*15:01-DRB5*01:01-DQA1*01:02-DQB1*06:02 or -(A*24:02)-B*52:01-C*12:02-DRB1*15:02-DRB5*01:02-DQA1*01:03-DQB1*06:01, resulting in significantly increased HLA-DRB1*15, -DRB1*15:01, -DQB1*06:01/06:02, -DQB1*06:02, and -DRB1*15:01-DQB1*06:02 frequencies compared with healthy Japanese controls. These findings indicate the involvement of specific HLA class II molecules in the pathomechanisms of IgG4 anti-NF155 antibody-positive CIDP.

Guillain-Barré Syndrome.

Guillain-Barré syndrome (GBS) is an acute immune-mediated polyradiculoneuropathy, and pathophysiologically classified into acute inflammatory demyelinating polyneuropathy (AIDP), acute motor axonal neuropathy (AMAN), and acute motor and sensory axonal neuropathy (AMSAN). The main pathophysiological mechanism is complement-mediated nerve injury caused by antibody-antigen interaction in the peripheral nerves. Antiglycolipid antibodies are most pathogenic factors in the development of GBS, but not found in 40% of patients with GBS. One of the principal target regions in GBS is the node of Ranvier where functional molecules including glycolipids are assembled. Nodal dysfunction induced by the immune response in nodal axolemma, termed "nodopathy," can electrophysiologically show reversible conduction failure, axonal degeneration, or segmental demyelination. To detect new target molecules in antiglycolipid antibody-negative GBS and to elucidate the pathophysiology in the subacute and the subsequent phases of the disorder are the next problems.

Intrathecal cytokine profile in neuropathy with anti-neurofascin 155 antibody.

OBJECTIVE: To characterize the CSF cytokine profile in chronic inflammatory demyelinating polyneuropathy (CIDP) patients with IgG4 anti-neurofascin 155 (NF155) antibodies (NF155+ CIDP) or those lacking anti-NF155 antibodies (NF155- CIDP). METHODS: Twenty-eight CSF cytokines/chemokines/growth factors were measured by multiplexed fluorescent immunoassay in 35 patients with NF155+ CIDP, 36 with NF155- CIDP, and 28 with non-inflammatory neurological disease (NIND). RESULTS: CSF CXCL8/IL-8, IL-13, TNF-α, CCL11/eotaxin, CCL2/MCP-1, and IFN-γ were significantly higher, while IL-1ß, IL-1ra, and G-CSF were lower, in NF155+ CIDP than in NIND. Compared with NF155- CIDP, CXCL8/IL-8 and IL-13 were significantly higher, and IL-1ß, IL-1ra, and IL-6 were lower, in NF155+ CIDP. CXCL8/IL-8, IL-13, CCL11/eotaxin, CXCL10/IP-10, CCL3/MIP-1α, CCL4/MIP-1ß, and TNF-α levels were positively correlated with markedly elevated CSF protein, while IL-13, CCL11/eotaxin, and IL-17 levels were positively correlated with increased CSF cell counts. IL-13, CXCL8/IL-8, CCL4/MIP-1ß, CCL3/MIP-1α, and CCL5/RANTES were decreased by combined immunotherapies in nine NF155+ CIDP patients examined longitudinally. By contrast, NF155- CIDP had significantly increased IFN-γ compared with NIND, and exhibited positive correlations of IFN-γ, CXCL10/IP-10, and CXCL8/IL-8 with CSF protein. Canonical discriminant analysis of cytokines/chemokines revealed that NF155+ and NF155- CIDP were separable, and that IL-4, IL-10, and IL-13 were the three most significant discriminators. INTERPRETATION: Intrathecal upregulation of type 2 helper T (Th2) cell cytokines is characteristic of IgG4 NF155+ CIDP, while type 1 helper T cell cytokines are increased in CIDP regardless of the presence or absence of anti-NF155 antibodies, suggesting that overproduction of Th2 cell cytokines is unique to NF155+ CIDP.

Clavariopsins C-I, Antifungal Cyclic Depsipeptides from the Aquatic Hyphomycete Clavariopsis aquatica.

Seven new cyclic depsipeptides, clavariopsins C-I (3-9), together with two known congeners, clavariopsins A and B (1 and 2), were isolated from the aquatic hyphomycete Clavariopsis aquatica. Their planar structures, which consist of nine amino acids and one α-hydroxy acid, were elucidated by NMR spectroscopy and HRESIMS. The absolute configurations were established by the advanced Marfey's method and chiral-phase HPLC analysis. Their antifungal and cytotoxic activities were evaluated against six plant pathogenic fungi (Botrytis cinerea, Magnaporthe oryzae, Colletotrichum orbiculare, Fusarium oxysporum, Alternaria alternata, and Aspergillus niger) and a cancer cell line (HeLa-S3), respectively. The majority of the compounds exhibited potent antifungal activity against the fungi tested (minimum inhibition dose = 0.01-10 µg/disk) and induced hyphal swelling in A. niger (minimum effective dose = 0.3-3 µg/disk), whereas the compounds exhibited no cytotoxicity toward the cancer cell line. The results suggest that the clavariopsins could be a promising class of antifungal agents.