NEWER TESTS IN NEUROLOGY - Metropolis …...NEWER TESTS IN NEUROLOGY DR RAJESH V BENDRE HOD,...
Transcript of NEWER TESTS IN NEUROLOGY - Metropolis …...NEWER TESTS IN NEUROLOGY DR RAJESH V BENDRE HOD,...
NEWER TESTS IN
NEUROLOGY
DR RAJESH V BENDRE
HOD, IMMUNOCHEMISTRY
METROPOLIS, MUMBAI
The Central Nervous System
was considered an Immunological Privileged Site
• Blood brain barrier (BBB)
• Proapoptotic molecules at BBB
• No MHC molecules on nerve cells
• No classical dendritic cells in the CNS
However,
• Existence of lymph drainage in the CNS
• Passage of T and B cells through BBB (hypothalamus)
• Microglia can process and present antigens
Interactions between the immune and the nervous system - Neural influences on the immune system
Neurotransmitters: acetylcholine, norepinephrine, serotonin, etc. Neuropeptides: Substance P, endorphin Neurotrophic growth factors: Nerve growth factor, etc
-Hormonal influences on the immune system - Epinephrine, glucocorticoids -Modulation of nerve cell function by immune and inflammatory mediators
Cytokines Reactive oxygen and nitrogen species
Similarities between nerve cells and immune cells
Synapses K+ channels in immune cells (electroimmunology)
Recent Advances in
Neuroimmunology
Classical Fields of
Neuroimmunology Research
Immune response to diseases of the nervous system
– Demyelinting/Autoimmune – MS, NMO
– Degenerative- related to GAD & NMDA receptors
– Neoplastic- antineuronal antibodies
– Infections- CSF pathogen specific IgG antibodies
Multiple Sclerosis An Immunogenetic Disease
MS
Immune Dysregulation
Genetic Predisposition • Twins studies
• HLA-DR2 (DRß1*1501)
(antigen presentation)
• IL-2Ra
• (regulatory T-cells)
• IL-7Ra
(memory T-cells)
Environmental Factors
Demographics/Epidemics
Microbial Agents
EBV
Vitamin D
MS – CSF OCB
Isoelectric focusing of CSF. Case patient samples are in lanes 4 (CSF) and 4’ (serum). The CSF
sample is highly positive for oligoclonal bands (arrows). The IgG
index was 0.7 (reference interval 0.3–0.8) and did not suggest
increased intrathecal synthesis. The serum/CSF albumin ratio was <9
indicating normal permeability of the blood brain barrier. Controls
are indicated on the gel. For comparison, other patients that are
negative for oligoclonal banding are shown in lanes 2, 3, and 5.
Pattern Bands Observed Associated Diseases
1 Polyclonal pattern (no discrete bands) in both
serum & CSF
Rare Multiple sclerosis Myelitis
CNS vasculitis Paraneoplastic syndromes
Systemic lupus erythematosis
2 Same number of OCB in
serum & CSF
Myelitis CNS vasculitits
Paraneoplastic syndromes Lupus
CNS infections Neoplastic meningitis
Behcet Disease Rasmussen Disease
Hashimoto encephalitis Lymphoproliferative disorders
Hepatitis C
3 OCB in both serum & CSF CSF has at least 2 more bands than serum
Multiple sclerosis Most CNS infections
4 More than 2 OCB in CSF & polyclonal pattern in
serum Most Multiple sclerosis
5 Monoclonal band in both
serum & CSF
Normal individuals Multiple sclerosis CNS lymphoma
CNS inflammatory disorders
Neuromyelitis Optica (NMO)
Aquaporin 4 antibodies by Indirect
Immunofluorescence –
a-Binding of serum AQP4-Ab to adult
mouse cerebellum as demonstrated by
immunohistochemistry. Magnified images
show staining of b- the microvasculature,
c - the Virchow–Robin spaces and d - the
pia mater. e–g | Binding of serum AQP4-
Ab to the surface of cultured human
embryonic kidney (HEK293) cells
transfected with human full length AQP4
(panel e; see panel f for higher
magnification) or nontransfected control
cells (panel g)
Aquaporin 4 IIF - Mosaic with rat cerebrum, cerebellum, transfected HEK cells
with aquaporin 4 & non-transfected HEK cells
ELISA for IgG aquaporin 4 is also available
IgG NMO
Rarely seen in SLE, Sjogren
syndrome
NMDA receptors
GAD receptors
Autoantibody IIF or blot assay Disease
association
GAD Cerebellar neuronal
cytoplasm, granular
positivity
Stiff syndrome
NMDA
(NR1)
(NR2 & 3)
Mosaic with rat
hippocampus & cerebellum,
transfected HEK cells with
NMDA-NR1 & non-
transfected HEK cells
Limbic
encephalitis
Psychiatric
lupus
VGKC
(caspr2,Ligi1)
Mosaic similar to NMDA in
process - under validation
Limbic
encephaltis
Autoantibodies &
Nervous system disorders-
Autoantibody IIF or blot assay Disease association
Myelin White matter granular positivity in
cerebellum, nerves with diffuse cylinders
unclear
Myelin associated
glycoprotein (MAG)
White matter granular positivity in
cerebellum, nerves with central clearing &
peripheral granularity
IgM gammopathy
associated, Guillian
Barre Syndrome
Ganglioside GM1 Euroline blot assay Guillian barre
syndrome, multifocal
motor neuropathy,
chronic
inflammatory
demyelinating
polyneuropathy
Ganglioside GQ1b Euroline blot assay Miller Fisher
syndrome
Neurofilament Few isolated thin fibrils in white matter in
cerebellum
Dysglobulinaemia
with polyneuropathy
Neuroendothelium Seen inside the blood vessels, can cause
interpretative problems in NMO
Unclear
Non-medullated
nerves
Positivity in only intestinal meyenteric
plexus
Chronic
inflammatory bowel
diseases
Line Blot Assay :
-For antibodies
against
Gangliosides
Anti- neuronal antibodies –
Paraneoplastic syndromes
Anti neuronal antibody IIF Disease association
ANNA-1 (anti-Hu) Cerebral & cerebellar neuronal nuclei, intestinal
meyenteric plexus
Subacute sensory neuronopathy –
SCLC, neuroblastoma
ANNA-2(Anti- ri) Cerebral & cerebellar neuronal nuclei, Absent
intestinal meyenteric plexus
Opsoclonus-myoclonus syndrome-
Breast CA, SCLC
Anti- yo (anti-purkinje cell) Cerebellar Purkinje cells cytoplasm Diploplia,dysarthria,tremors- ovary,
breast,uterus CA
Anti- tr(anti-purkinje cell) Cerebellar Purkinje cells cytoplasm & dendritic
processes
Exact association unclear
Anti - amphyphysin Cerebellar neuronal cytoplasm- granular
positivity
Stiff person syndrome
-SCLC, breast CA
Anti – CV2 Cerebellar neuronal cytoplasm- weak diffuse
positivity
SCLC, thymoma
Anti - Ma Cerebellar neuronal nucleoli positive Brain stem encephalitis
Anti Ma1- breast CA
Anti Ma2/Ta- testis tumours
These antibodies can occur upto 5 years before the appearance of detectable tumour
Associated ANA can interfere in interpretation & Blot assay recommended in such cases to confirm
antineuronal antibodies
Anti- neuronal antibodies –
Indirect
Immunofluorescence:
Primate Cerebellum:
Antibodies against GAD
Yo (top),
Against Hu and Ri
(middle).
Peripheral nerves:
Antibodies against
myelin and MAG
(bottom).
Line Blot Assay :
- For antibodies seen in
Paraneoplastic syndromes
CNS Infections –
CSF Pathogen Specific IgG
Neuromuscular disorders
Neuromuscular junction disease is a condition where
the normal conduction through the neuromuscular
junction fails to function correctly.
• Post synaptic -
In myasthenia gravis, the End Plate Potential
(EPP) fails to effectively activate the muscle fiber
due to an autoimmune reaction against
acetylcholine receptors, resulting in muscle
weakness and fatigue.
Most commonly by auto-antibodies against the
acetylcholine receptor. It has recently been
realized that a second category of gravis is due to
auto-antibodies against MuSK.
• Pre synaptic –
In Lambert-Eaton myasthenic syndrome, is
usually associated with presynaptic antibodies to
the voltage-dependent calcium channel.
These autoantibodies namely ACRAB, MUSK &
VGCC can be tested in serum by
immunoprecipitation reaction using
Radioimmunoassay (RIA) technique
Myositis – serum markers