Table 1.

Clinical and paraclinical features of patients with encephalitis-associated autoantibodies in Laos

		IgG-specificity and endpoint titres
Patient age (y) and gender	Clinical features and CNS syndrome	Serum	CSF	CSF WBC (cells/uL)	CSF: serum glucose ratio	CSF protein (mg/dL)	Identified infection	Outcome	Meeting criteria for possible autoimmune encephalitis?19
A. 22M	Prodromal fever then acute confusion, neck stiffness, agitation, delirium, hypersomnolence/insomnia, catatonia; meningoencephalitis	NMDAR 1:200	NMDAR 1:200	15	0.50	55	None	Discharged, not improved - diagnosis catatonic schizophrenia	YES
B. 45F	Prodromal fever, headache, neck stiffness then acute confusion, drowsiness, agitation, delirium; admitted initially to psychiatry; meningoencephalitis	NMDAR 1:500	NMDAR 1:2	50	0.81	28	None	Discharged moribund	YES
C. 35M	7-d history of fever and headache followed by acute confusion, drowsiness; meningoencephalitis	NMDAR 1:500	Neg.	85	0.35	55	Pus in ears, culture negative	Deceased	NO
D. 53M	10-d history of fever, headache, neck stiffness, cough, vomiting, confusion, right leg weakness; meningoencephalitis	NMDAR 1:400	Neg.	610	CSF 2.0 mmol/L*	276	TB culture CSF positive	Deceased, diagnosis TB meningitis	NO
E. 45M	Acute onset of fever, headache, neck stiffness, agitation, drowsiness, confusion, with single convulsion; meningoencephalitis	NMDAR 1:200	Neg.	10	0.43	38	Serum murine typhus IgM+, Rickettsia typhi PCR negative	Discharged well	NO
F. 73M	Acute onset of fever, neck stiffness, delirium, agitation and altered consciousness; admitted initially to psychiatry; meningoencephalitis	NMDAR 1:200	Neg.	5	CSF 5.2 mmol/L*	30	None	Discharged moribund	NO
G. 51M	1-mo weight loss preceding acute onset fever, headache and neck stiffness; meningitis; suspected underlying malignancy	CASPR2 1:800	Neg.	0	1.09	72	N. meningitidis PCR positive on CSF (culture negative)	Discharged AMA, no improvement	NO
H. 57M	7-d fever, headache, cough and rash without seizures or confusion	GABAAR 1:160	GABAAR 1:8	18	0.34	20	None	Unknown	NO

Abbreviations: AMA, against medical advice; CASPR2, contactin-associated protein-like 2; CSF, cerebrospinal fluid; GABA_AR, gamma-amino butyric acid A receptor; NMDAR, N-methyl-D-aspartate receptor; WBC, white blood cells.

The following cut-offs were used for positive serum neuronal autoantibody titres: NMDAR antibodies >1:100, CASPR2 antibodies >1:500, GABA_AR antibodies >1:50. In CSF, any antigen-specific reactivity is considered positive.

*no concurrent serum glucose available for these patients.

See Dubot-Pérès et al. (2019)¹¹ for diagnostic techniques for the pathogens given in the Identified infection column.

The criteria for possible autoimmune encephalitis used are = diagnosis can be made when all three of the following criteria have been met: (a) subacute onset (rapid progression of less than 3 mo) of working memory deficits (short-term memory loss), altered mental status or psychiatric symptoms; (b) at least one of the following: new focal CNS findings, seizures not explained by a previously known seizure disorder, CSF pleocytosis (white blood cell count of more than five cells per mm³), MRI features suggestive of encephalitis; and (c) reasonable exclusion of alternative causes.¹⁹