@article{zoehner_reduced_2019,
	title = {Reduced serum immunoglobulin G concentrations in multiple sclerosis: prevalence and association with disease-modifying therapy and disease course},
	volume = {12},
	issn = {1756-2864, 1756-2864},
	url = {http://journals.sagepub.com/doi/10.1177/1756286419878340},
	doi = {10.1177/1756286419878340},
	shorttitle = {Reduced serum immunoglobulin G concentrations in multiple sclerosis},
	abstract = {Background:
              In multiple sclerosis ({MS}), the frequency of hypogammaglobulinemia is unknown. We aimed to evaluate the frequency of reduced immunoglobulin (Ig) concentrations and its association with immunotherapy and disease course in two independent {MS} cohorts.
            
            
              Methods:
              In our retrospective cross-sectional study, {MS} patients and control patients with head or neck pain from Bern University Hospital (Bern, Switzerland) and Eginition University Hospital (Athens, Greece) were included. The lower limits of normal ({LLN}) for serum Ig concentration were {IgG} {\textless} 700 mg/dl, {IgM} {\textless} 40 mg/dl, and {IgA} {\textless} 70 mg/dl. Mann–Whitney U test, analysis of variance test, and multiple linear regression analysis were employed.
            
            
              Results:
              In total, 327 {MS} patients were retrospectively identified (Bern/Athens: n = 226/101). Serum {IgG} concentrations were frequently under {LLN} in both {MS} cohorts (Bern/Athens: 15.5\%/14.9\%), even when considering only untreated patients (Bern/Athens: 7.9\%/8.6\%). {MS} patients ( n = 327) were significantly more likely to have {IgG} concentrations below {LLN} and below 600 mg/dl in comparison with controls ( n = 58) ( p = 0.015 and 0.047, respectively). Between both patient groups, no significant differences were found in frequencies of {IgA} and {IgM} concentrations under {LLN} [ n ({MS} patients/controls): {IgA} 203/30, {IgM} 224/24]. Independently of age, secondary progressive {MS} patients had lower {IgG} concentrations than relapsing–remitting and primary progressive patients (both: p ⩽ 0.01). After adjusting for sex, age, and disease course, {IgG} concentrations were lower in patients treated with rituximab ( p = 0.001; n = 42/327), intravenous corticosteroids ( p {\textless} 0.001; n = 16/327), natalizumab ( p {\textless} 0.001; n = 48/327), and fingolimod ( p = 0.003; n = 6/327).
            
            
              Conclusion:
              Our study demonstrated high prevalence rates of reduced serum {IgG} concentrations in {MS} patients with and without disease-modifying treatments. The significance of lower {IgG} concentrations at the levels noted is unclear considering that infections or interference with antibody production generally occur when {IgG} levels are much lower, at or below 400 mg/dl. However, the information is useful to monitor {IgG} levels especially with anti-B-cell therapies and consider {IgG} substitution when levels drop below 400 mg/dl.},
	pages = {175628641987834},
	journaltitle = {Therapeutic Advances in Neurological Disorders},
	shortjournal = {Ther Adv Neurol Disord},
	author = {Zoehner, Greta and Miclea, Andrei and Salmen, Anke and Kamber, Nicole and Diem, Lara and Friedli, Christoph and Bagnoud, Maud and Ahmadi, Farhad and Briner, Myriam and Sédille-Mostafaie, Nazanin and Kilidireas, Constantinos and Stefanis, Leonidas and Chan, Andrew and Hoepner, Robert and Evangelopoulos, Maria Eleftheria},
	urldate = {2021-02-24},
	date = {2019-01},
	langid = {english},
	keywords = {peer-reviewed},
}