SummaryCellular senescence is accompanied by a senescence‐associated secretory phenotype (SASP). We show here that primary human senescent CD8+ T cells also display a SASP comprising chemokines, cytokines and extracellular matrix remodelling proteases that are unique to this subset and contribute to age‐associated inflammation. We found the CD8+ CD45RA + CD27− EMRA subset to be the most heterogeneous, with a population aligning with the naïve T cells and another with a closer association to the effector memory subset. However, despite the differing processes that give rise to these senescent CD8+ T cells once generated, they both adopt a unique secretory profile with no commonality to any other subset, aligning more closely with senescence than quiescence. Furthermore, we also show that the SASP observed in senescent CD8+ T cells is governed by p38 MAPK signalling.

The histamine content in plasma samples obtained from a group of healthy blood donors, from blood stored in citrate-phosphate-dextrose supplemented with adenine (CPDA) packs for up 28 days, and from the side arm of a transfusion line was measured by radio-enzymatic assay. Healthy donors had a mean plasma histamine content of 0.79 ng per ml. Blood stored in CPDA initially showed a similar histamine level (0.69 ng/ml on day 3 of storage), but there was a progressive rise with time, and at 28 days, the level was 20.5 ng per ml. The increase in histamine is best described by a positive exponential and may be explained by a process whereby the plasma histamine level increases the degree of histamine release from blood cells. The histamine levels in the blood infused into patients tended to be higher than those found in the stored units of the same age, if these packs were less than 7 days old. This may have been caused by the unit becoming warmer during transfusion. We speculate that the histamine levels in the older units of stored blood were high enough to cause or augment transfusion reactions and that the storage age of blood may have a bearing on the incidence of transfusion reactions.

The safety and ethical aspects of blood donation are examined in the light of current legislation and practice. The advantages and disadvantages of voluntary and paid donation are looked at in view of recent data concerning risk factors in various potential donor groups. It is concluded that voluntary, non-remunerated blood donation remains the safest and most ethical means of securing the blood supply.

Plasma and whole blood histamine levels and white cell counts have been monitored over a 6-week period of storage in standard citrate-phosphate-dextrose supplemented with adenine (CPDA) blood packs, add-back blood packs, and also CPDA and add-back packs which were subjected to a microfiltration process at the time of collection. Our results indicate that the plasma histamine level rises and the white blood count falls progressively with time, the former being most marked after the 3rd week of blood storage. At 6 weeks, there was no significant difference between the plasma and whole blood histamine level, suggesting that the entire complement of histamine in blood was now in plasma. Microfiltration substantially reduced the white cell count in the packs, and this was reflected in a greatly reduced whole blood and (subsequently) plasma histamine concentration.

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The family of a male Lu(a-b-) propositus whose red cells showed some characteristics of the dominant and some of the recessive type of Lu(a-b-) phenotype was studied. The investigation revealed a third genetic background for this rare phenotype, an X-borne suppressor recessive in effect. The notation proposed is XS1 for the normal gene and XS2 for the suppressor gene which affects the expression of Lutheran and other antigens.

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