PMC5625000_01
Imaging and (neuro)immunological findings in a young patient with acute mercury intoxication of unknown etiology. (A) Serial magnetic resonance imaging of the brain at indicated time points demonstrating progressive cortical and subcortical atrophy and diffusion restriction, especially in the temporal lobes. (B) Results of lumbar puncture at indicated time points. Left panel: Total numbers of cerebrospinal fluid (CSF)-derived cells (red) and protein (blue) levels are depicted. Dotted lines indicate the mean +- SD of 25 control patients with somatoform disorders. Right panel: CSF-derived cells were stained for flow cytometric analysis using fluorochrome-conjugated monoclonal antibodies. Following acquisition, CD3+CD56- T cells were further subdivided into CD4+ (blue) and CD8+ (red) and analyzed for the expression of the activation marker HLA-DR.
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F1
Clinical deterioration was accompanied by progressive and widespread cortical and subcortical edema and atrophy demonstrated by serial MRI over the period of 4 months (Figure 1A). Treatment was stopped due to unchanged clinical condition of the patient, poor prognosis, and progressive deterioration on MRI (as shown in Figure 1A). Lymphocyte counts and CD4/CD8 ratio decreased over time within the CSF, while the CSF protein level increased indicating progressive dysfunction of the blood-brain barrier (normal level, <500 mg/l) (Figure 1B:left panel). HLA-DR on both CD4+ and CD8+ T-cell subsets was also analyzed. HLA-DR expression on CD8+ T lymphocytes clearly increased during the observed period of time up to 17.58% (normal level, <6.19 +- 4.09%), while the percentage of HLA-DR+CD4+ T cells remained more or less the same within the CSF (normal level, <4.58 +- 1.92%) (Figure 1B:right panel).
Immune-cell function in acute mercury poisoning. Ex vivo analyses of peripheral blood mononuclear cells of the patient were performed in comparison to respective healthy controls (Ctrl; N = 4, mean +- SD). [(A):left] The frequencies of CD4+CD3+HLA-G+ and CD4+CD3+Foxp3+ regulatory T (Treg)-cell subsets were determined by flow cytometric analysis. [(A):right] Furthermore, expressions of FoxP3+Helios+ and FoxP3+CD39+ on CD4+CD25+CD127low Treg cells were assessed. (B) Levels of CD40, CD80, CD83, CD86, CD87, and MHC-II on CD1c+CD11c+CD11b+CD19- dendritic cells are shown (right). FI, fluorescence intensity.
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F2
Flow cytometric analysis of peripheral blood mononuclear cells showed an unaltered frequency of CD4+CD3+HLA-G+ and CD4+CD3+Foxp3+ regulatory T (Treg) cells in comparison to healthy controls (Figure 2A:left). Treg cells compared with the reference values (2.82 +- 1.10% for HLA-G and 8.16 +- 2.15% for FoxP3; N = 4). Further evaluation of regulatory effector molecules demonstrated no difference for the expression of Helios (controls: 62.45 +- 3.92% vs. patient: 64.82%); however, CD39 markedly decreased on FoxP3 expressing CD4+CD25+CD127low Treg cells (controls: 35.07 +- 2.29% vs. patient: 10.30%) (Figure 2A:right) pointing toward impaired function of Treg cells. The dendritic cell compartment showed no overt alterations as indicated by the levels of CD40, CD80, CD83, CD86, CD87, and MHC-II on CD1c+CD11c+CD11b+CD19- dendritic cells (Figure 2B).
Blood count and hemostaseologic response in acute mercury poisoning of unknown origin. (A) Red blood cells (RBC), hemoglobin (Hb), and hematocrit (HCT) of the patient are shown in comparison to a respective healthy control (Ctrl). (B) The patient's endogenous thrombin potential (ETP) level was determined in relation to Ctrl. (C) Flow cytometric analysis of agonist [adenosine diphosphate (ADP)- and collagen]-induced binding of soluble fibrinogen to platelets from patient vs. Ctrl. (D) Flow cytometric analysis of agonist (ADP and collagen)-induced binding of soluble fibrinogen to control platelets in presence of high 2,3-dimercapto-1-propanesulfonate (DMPS) doses. AU, arbitrary units.
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F3
Levels of red blood cells, hemoglobin, and hematocrit were decreased in peripheral blood of the patient in comparison to a respective control (Figure 3A). However, coagulation of the patient was impaired as indicated by the endogenous thrombin potential (ETP) measured in platelet-poor plasma (Figure 3B). In detail, stimulation of patient's platelets with adenosine diphosphate (ADP) and collagen in platelet-rich plasma in vitro resulted in a decreased binding of soluble fibrinogen compared to control binding (Figure 3C). Analog measurements with a high dose of DMPS revealed that the observed effect is DMPS independent (Figure 3D).