Martti Syrjälä

In vitro and in vivo behavior of 111In‐labelled platelets: An experimental study of healthy male volunteers

The aim of this study was to obtain a critical evaluation of a simple method for labelling platelets with 111In‐oxine. All experiments were carried out on healthy volunteers. 65 ± 7 (SD) % of the platelets in collected blood were labelled and reinjected. As compared to control experiments, only in response to a low final ADP concentration (1.0 μmol/l) did 111In‐labelled platelets show reduced in vitro aggregability. The mean platelet volume for 111In‐labelled platelets was slightly lower than the mean platelet volume in whole blood. The results for initial platelet recovery and platelet mean lifespan closely agreed with those of other studies in which considerably higher platelet extraction from whole blood was obtained. After injection, the splenic uptake and blood disappearance of 111In‐labelled platelets followed a monoexponential function with almost identical rate constants. By compartmental analysis of the equilibration of platelets between blood and spleen, the splenic blood flow was estimated to be 4.8 ± 1.9 (SD) % of the total blood volume/min; the intrasplenic platelet transit time was 9.7 ± 1.6 (SD) min, and the exchangeable splenic platelet pool 31 ± 8 (SD) %. Highly significant relationships were present between the splenic blood flow and the splenic platelet pool size, as well as between the splenic blood flow and the initial platelet recovery. It is concluded that the requirements for adequate interpretation of platelet kinetics are well met with the present method for harvesting and labelling of platelets.

Platelets and polymorphonuclear leukocytes in experimental ocular inflammation in the rabbit eye

Accumulation of111indium-oxine (111In)-labelled platelets and the kinetics of111In-labelled polymorphonuclear leukocytes (PMNLs) were studied in the anterior eye during neurogenic inflammation (induced by topical neutral formaldehyde) or after paracentesis in the rabbit, after formaldehyde irritation, 40 times more platelets were found in the aqueous humor 60 min later than in the control eyes and 400 times more after paracentesis. Platelets were found to be increased in the ciliary body, but not in the iris or choroid. Under light microscopy, some of the blood vessels in the ciliary processes were occluded and filled with red blood cells and platelets. The amount of PMNLs increased in the aqueous humor 15–20 h following formaldehyde irritation. After paracentesis, increased amounts of PMNLs were found in the iris and ciliary body 3–6 h later, while in the aqueous humor PMNLs were observed already 2 h. In the present study, increased amounts of111In-labelled platelets and PMNLs were demonstrated in the anterior eye during experimental ocular inflammation. This method provides a useful tool for evaluating the accumulation of cells or the cell kinetics in ocular tissues during experimental inflammation.

Platelet associated IgG, platelet mean life span and treatment with intravenous immunoglobulin in idiopathic thrombocytopenic purpura

The clinical significance of platelet associated IgG in ITP detected by direct platelet suspension immunofluorescence test (PSIFT) was studied. The platelet mean life span (MLS) was measured with 111In‐labelled platelets in 17 adult patients. All the patients had shortened platelet MLS. The direct PSIFT was positive in 14 patients. Patients were initially treated with prednisone; 12 patients with poor response to the drug were splenectomised. 8 of these 12 patients were treated with intravenous immunoglobulin (IvIg) before splenectomy. The response to IvIg was as good or better in the 3 patients with negative PSIFT, than in the 5 patients with positive PSIFT.

Intestinal accumulation of 111In-granulocytes in patients studied because of occult infection

Abstract111In-granulocyte scintigraphy was performed on 245 patients in whom a localized infection was suspected. In 123 patients scintigraphy was positive and of these 35 (28%) had intestinal accumulations of 111In-granulocytes. Specific local causes for the intestinal uptake of radioactivity were antibiotic associated colitis (eight patients), local pyogenic bowel infection (four patients), systemic disease (two patients), bowel necrosis (two patients), colonic cancer (one patient) and Stevens-Johnsons syndrome (one patient). Nonspecific mechanisms of bowel accumulation were desquamation of labelled granulocytes (12 patients) and bleeding (two patients). In three cases the mechanism of colonic accumulation of granulocytes was not revealed. These results show that unexpected accumulations of labelled granulocytes in the gut is not a rare phenomenon and is often due to clinically significant intestinal inflammation or other disease, especially in patients who do not have signs of respiratory, pancreatic or oesophageal inflammation causing desquamated granulocytes to accumulate in the gut.

Season and time of day affect capillary blood hemoglobin level and low hemoglobin deferral in blood donors: analysis in a national blood bank

Low hemoglobin (Hb) is the most common reason for temporary blood donor deferral. However, factors that affect Hb measurement may not portray donor health but reflect external circumstances.

Positive 111In-granulocyte scintigraphy in a patient with focal leukemic blast cell infiltrations

A patient with acute myeloid leukemia was investigated with 111In-granulocyte scintigraphy to reveal possible sites of infection. 111In-granulocytes accumulated in areas of leukemic blast cell infiltration leading to a false-positive scintigram. This possibility must be kept in mind when studying leukemic patients using labeled leukocytes.

Retrospective analysis of capillary hemoglobin recovery in nearly 1 200 000 blood donor returns

Measuring the concentration of capillary hemoglobin (cHb) is a standard procedure before blood donation. To further assess the time period needed for cHb recovery after blood donation and to have a more in-depth understanding of features of recovery, we used data-mining tools in a large, retrospective data pool containing all 1 163 524 donor returns that took place in Finland in 2010 to 2015. The results show that the average recovery times for cHb to return back to the level preceding donation were substantially longer, over 200 days in all age groups, than were the minimum allowed donation intervals. cHb recovery was especially poor in women under the age of 30 who returned to donate soon after the minimum allowed donation interval. It was of interest that frequent donors recovered substantially faster, with the average recovery times of ∼100 days in men and ∼200 days in women, than did infrequent donors, suggesting that there is a subpopulation of donors who can donate frequently without fear of iron deficiency. Return interval in fact explained only 1% of the variation in cHb recovery, which points to unknown, individual features, such as genetic or lifestyle factors, warranting further studies and suggesting that simply extending the allowed donation intervals may not suffice to improve cHb recovery. The study demonstrates that data mining of blood bank records is a powerful tool for depicting features of blood donor population.