Low performance in attention testing is associated with reduced grey matter density of the left inferior frontal gyrus in euthyroid patients with Hashimoto's thyroiditis.

Hashimoto's thyroiditis (HT) can casually co-occur with an encephalopathy associated with autoimmune thyroid disease. Recently we found an increased occurrence of weaknesses in sustained attention and response inhibition in a subgroup of euthyroid patients with HT as obtained by the d2 attention test. Previous studies in healthy subjects and patients with brain lesions demonstrated a pivotal role for the left inferior frontal gyrus (LIFG) in these skills. Therefore, we studied the association between the performance in the d2 test and grey matter (GM) density of the LIFG in 13 euthyroid patients with HT compared to a control group of 12 euthyroid patients with other thyroid diseases. A significant correlation between GM density and d2 test total score was detected for the opercular part of the LIFG in patients with HT (p<0.001), but not in the control group (p=0.94). Regression in patients with HT was significantly stronger than in the control group (p=0.02). Moreover, GM density was significantly reduced when comparing HT patients with control patients that scored in the lower third during d2 attention testing (p<0.05). It can be concluded that in HT performance in the d2 test correlated with GM density of the LIFG. Particularly low achievement was associated with reduced GM density of this brain region suggesting an influence of autoimmune processes on the frontal cortex in this disease. This could be due to not yet known antibodies affecting brain morphology or an influence of thyroid antibodies themselves.

Pharmacokinetics of natural mistletoe lectins after subcutaneous injection.

PURPOSE: Knowledge of natural mistletoe lectins (nML) pharmacokinetics can be regarded as essential for further rational studies with mistletoe preparations. Studies with intravenous application of a recombinant type II ribosome inactivating protein (rML) analogous to nML revealed a short half-life of about 13 min in cancer patients. This open-label, phase I, monocenter clinical trial was performed in order to describe the pharmacokinetics of nML. METHODS: In 15 healthy male volunteers aged 18-42 years, nML were detected with a modified sandwich immuno-polymerase chain reaction (PCR) technique (Imperacer, Chimera Biotec) after single subcutaneous injection of a mistletoe extract (abnobaVISCUM(R) Fraxini 20 mg) with marketing authorization containing about 20 microg nML/ml. Secondary objectives were safety and the number of activated natural killer cells (CD54(+)/CD94(+)). RESULTS: In none of the volunteers were nML detectable before the injection, and in all volunteers, nML were detected in serum samples after injection. Individual variability, however, was large. Mean and median peak concentrations were reached 1 and 2 h after injection, respectively. In some volunteers, nML were still detectable at the final investigation 2 weeks after injection. The injection resulted in fever and flu-like symptoms in all volunteers, but no serious adverse events occurred. All symptoms and local reactions at the injection site completely disappeared within a range of 4-95 days. The number of activated natural killer (NK) cells did not change. CONCLUSIONS: Natural ML from abnobaVISCUM Fraxini 20 mg are detectable in serum after a single subcutaneous injection. Detectability is considerably longer compared with intravenously administered rML. The subcutaneous injection of this preparation without usual pretreatment with lower doses results in short-lasting fever and other flu-like symptoms.

In vitro immunoreactivity towards lectin-rich or viscotoxin-rich mistletoe (Viscum album L.) extracts Iscador applied to healthy individuals.

The aim of the study was to investigate how exposure to mistletoe extracts in vivo may influence cellular immune reactions by peripheral blood mononuclear cells (PBMC). 47 healthy individuals were exposed for twelve weeks either to Iscador Quercus special (IQ; rich in mistletoe lectin [ML]) (n = 16), to Iscador Pinus (IP; poor in ML but rich in viscotoxin) (n = 15), or to placebo (physiological saline) (n = 16). PBMC were isolated before exposure, during exposure in week 4, 8 and 12, as well as 13 weeks after last exposure (week 25) and incubated for 7 days with IQ or IP. Proliferative response and cytokine release were determined (type 1 cytokines: interferon [IFN]-gamma, tumor necrosis factor [TNF]-gamma, type 2 cytokines: interleukin [IL]-5, IL-13, macrophage/ monocyte-cytokines: IL-1, TNFalpha). IP- and IQ incubation of PBMC from non-exposed individuals lead to a significant increase of proliferation and production of all cytokines. There was a significant increase of IQ-induced TNFalpha (but not IL-1) production by PBMC in week 25 in individuals receiv-type 2-cytokines IL-5 and IL-13 significantly decreased during the observation period (p < 0.05 compared to placebo in week 8). These data indicate that IP seems to contain an antigen, which decreases type 2 reactivity. Furthermore, a component present preferentially in IQ seems to activate the production of the monocyte/ macrophage-related cytokine TNFalpha by PBMC. Intriguingly, also in individuals receiving placebo injections immunological alterations were detected during the observation period.

Immunologic effects of mistletoe lectins: a placebo-controlled study in healthy subjects.

The subcutaneous application of lectin-rich mistletoe preparations such as Iscador Quercus (IQ; Weleda Company, Schwäbisch Gmünd, Germany) results in a peripheral eosinophilia. Our goal was to investigate whether this effect is related to mistletoe lectin (ML) and whether it is caused by a response of the specific immune system. In a double-blinded study, 43 volunteers were randomized to one of four treatment groups: (1) IQ, (2) ML that was derived from IQ, (3) IQ that was depleted of ML, and (4) placebo. The respective preparations were applied subcutaneously twice per week for 8 weeks, in increasing doses. Weekly the differential blood count was analyzed. Every 4 weeks interferon-gamma, interleukin-5 (IL-5), and granulocyte-macrophage colony stimulating factor (GM-CSF) were determined in cultures from peripheral mononuclear cells after stimulation with IQ. IQ and ML resulted in significant eosinophilia compared with placebo and ML-depleted IQ. Furthermore, the leukocyte and granulocyte counts were increased in the IQ and ML groups compared with placebo. GM-CSF, interferon-gamma, and IL-5 increased after ex vivo in vitro stimulation with IQ in the IQ and ML groups, and were significantly different from placebo in the IQ group but not in the ML group. Eosinophilia during therapy with mistletoe preparations is due to its content of ML. This effect might be related to a stimulation of IL-5 and/or GM-CSF, which was demonstrated ex vivo in vitro. ML resulted in a temporary increase of the granulocyte count, which is probably related to an acute-phase reaction.

Induction of antibodies to viscotoxins A1, A2, A3, and B in tumour patients during therapy with an aqueous mistletoe extract.

Mistletoe extracts exert immunomodulatory properties on immunocompetent cells of the innate as well as the specific immune system. These effects have been mainly ascribed to mistletoe lectin 1 (ML-1) present in most of the extracts. However, it became evident that also other components of these extracts may induce immunological reactions, and especially viscotoxins (VT) may be of relevance. Aim of the study was, therefore, to evaluate whether VT like ML-1 could activate B-cells and lead to the production of VT-specific antibodies. Sera from 26 patients with different tumours who were treated with the mistletoe extract ABNOBAviscum Mali (AM) 4 for at least 18 weeks were analysed before therapy and after 3, 6, 9, 12, and 18 weeks. Sera were tested by ELISA against the four viscotoxins A1, A2, A3, B, as well as against ML-1. Within the observation period twenty-four (92%) of the 26 patients developed antibodies to at least one of the four VT and 25 (96%) to ML-1. In most instances, anti-VT antibodies appeared after 6-9 weeks of treatment. The antibodies were predominantly of the IgG type belonging preferentially to the IgG1 and IgG3 subclass. IgE antibodies were found only to VT-B and to ML-1. There was no relation between the development of antibodies to VT and ML-1, and also cross-reactivity could be excluded with high probability. These data indicate that not only ML-1 but also VT induce immunological responses in patients treated with mistletoe extracts. Whether there is any relationship to the postulated anti-tumour effect of mistletoe extracts has, however, still to be evaluated.

Effects of a lectin- and a viscotoxin-rich mistletoe preparation on clinical and hematologic parameters: a placebo-controlled evaluation in healthy subjects.

BACKGROUND AND OBJECTIVES: Mistletoe preparations, which are widely used among patients with cancer in Germany, have immunomodulating properties in vitro and in vivo. The aim of this evaluation was to determine and compare the effects of a lectin-rich (Iscador Qu [IQ] special, Weleda Company, Schwäbisch, Gmünd, Germany.) and a lectin-poor but viscotoxin-rich (Iscador Pini [IP] Weleda Company) mistletoe preparation on clinical and hematologic parameters in healthy subjects. DESIGN: In a double-blinded study, 48 volunteers were randomized to one of three groups: 16 received IQ or IP in increasing doses or placebo twice per week subcutaneously for 12 weeks. The differential blood count and the acute phase markers haptoglobin and C-reactive protein were examined weekly and the symptoms were scored using standardized questionnaires. RESULTS: IQ resulted in significant eosinophilia (315 +/- 109) beginning at week 5 (until week 12) compared to IP (183 +/- 120) or placebo (200 +/- 179). Furthermore, the acute phase marker haptoglobin was significantly increased in the IQ group during week 4. Dose-dependent local reactions (LRs) at the injection site occurred in all subjects who received mistletoe preparations but were stronger in the IQ-treated subjects than in the IP-treated group. The LRs observed in the IQ-treated group were characterized by stronger itching and longer latency than LRs in the IP-treated group (p < 0.05). Severe side-effects did not occur in any of the probands. CONCLUSIONS: IQ but not IP can induce eosinophilia in healthy individuals, and this may be related to its content of mistletoe lectins. In contrast, exposure to the viscotoxin-enriched extract IP did not result in specific changes of hematologic parameters. Furthermore, intensity and time course of local reactions seemed to depend on the concentration of mistletoe lectins in those extracts.