Bone marrow cell transplantation time-dependently reverses G-CSF effects after stroke in hypertensive rats

Granulocyte colony-stimulating factor (G-CSF) is a hematopoietic cytokine and preclinically proven neuroprotectant. A potential reason for the clinical failure of G-CSF may be that relevant G-CSF effects such as the mobilization of mononuclear hematopoietic stem/progenitor cells from the bone marrow may take too long in humans (up to 9 days) to counter initial stroke consequences. Systemic transplantation of bone marrow mononuclear cells (BMMNCs) is feasible within a relatively short time after stroke onset and may provide an external resource of aforementioned stem/progenitor cells, thereby “bridging the gap” until G-CSF comes to full effect. Male spontaneously hypertensive rats (SHR) were randomly assigned into four groups after permanent middle cerebral artery occlusion (MCAO). Groups 1–3 received IP G-CSF treatment (50 μg/kg) for 5 days starting 1 h after stroke onset. Groups 2 and 3 also received 1.5 × 107/kg BMMNCs IV at 6 or 48 h following stroke, respectively. Group 4 received placebo treatment. Functional deficits (adhesive removal test), infarct volume, and edema (T2 TSE MRI) were repeatedly assessed for 1 month. Peripheral leukocyte counts and BMMNC biodistribution were analyzed by flow cytometry during the first week after stroke. G-CSF monotreatment reduced functional deficits (p 0.05 each). Surprisingly, BMMNC transplantation at 48 h abolished G-CSF effects. Early biodistribution studies (at 52 h after stroke onset) revealed splenic accumulation of granulocytes and BMMNCs as well as a granulocyte overload in the peripheral circulation and the brain (p < 0.05). Splenic accumulation of transplanted BMMNCs may have impaired peripheral granulocyte clearance. Subsequently, increased granulocyte numbers in the circulation and the poststroke brain prompted a proinflammatory bias of the innate immune system’s response to stroke, ultimately abolishing G-CSF effects. These surprising findings indicate that systemic effects of experimental stroke therapies need to be carefully considered when assessing the therapeutic potential of such novel approaches

Routine diagnostics for neural antibodies, clinical correlates, treatment and functional outcome.

To determine frequencies, interlaboratory reproducibility, clinical ratings, and prognostic implications of neural antibodies in a routine laboratory setting in patients with suspected neuropsychiatric autoimmune conditions. Earliest available samples from 10,919 patients were tested for a broad panel of neural antibodies. Sera that reacted with leucine-rich glioma-inactivated protein 1 (LGI1), contactin-associated protein-2 (CASPR2), or the voltage-gated potassium channel (VGKC) complex were retested for LGI1 and CASPR2 antibodies by another laboratory. Physicians in charge of patients with positive antibody results retrospectively reported on clinical, treatment, and outcome parameters. Positive results were obtained for 576 patients (5.3%). Median disease duration was 6 months (interquartile range 0.6-46 months). In most patients, antibodies were detected both in CSF and serum. However, in 16 (28%) patients with N-methyl-D-aspartate receptor (NMDAR) antibodies, this diagnosis could be made only in cerebrospinal fluid (CSF). The two laboratories agreed largely on LGI1 and CASPR2 antibody diagnoses (κ = 0.95). The clinicians (413 responses, 71.7%) rated two-thirds of the antibody-positive patients as autoimmune. Antibodies against the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR), NMDAR (CSF or high serum titer), γ-aminobutyric acid-B receptor (GABABR), and LGI1 had ≥ 90% positive ratings, whereas antibodies against the glycine receptor, VGKC complex, or otherwise unspecified neuropil had ≤ 40% positive ratings. Of the patients with surface antibodies, 64% improved after ≥ 3 months, mostly with ≥ 1 immunotherapy intervention. This novel approach starting from routine diagnostics in a dedicated laboratory provides reliable and useful results with therapeutic implications. Counseling should consider clinical presentation, demographic features, and antibody titers of the individual patient