Lymphocyte subpopulations in malaria infected individuals living in an endemic area.

Development of partial immunity in people living in malaria endemic area is complex. For better understanding, the lymphocyte subpopulations from infected patients were evaluated by flow cytometer before any antimalarial treatment. In P. vivax infection, the frequency of T-helper type 1 (Th1) was decreased significantly (p = 0.042). In contrast, the number of T- helper type 2 (Th2) was increased significantly (p = 0.001). These trends have also been observed in P. faciparum infection. The Th2 predominant response to the natural malaria infection is likely due to persistent stimulation by Plasmodium species. In P. falciparum infection, CD8+ cytotoxic lymphocytes were significantly reduced (p = 0.007). However, such changes were not found in P. vivax infection. This might suggest that CD8+ cell responses to different Plasmodium spp in a different way. Both Th2 activation and CD8+ cell suppression may reflect less protective effects and chronic malaria infection could be established.

Iron stores in autologous blood donors.

Depletion of body iron stores is a major factor limiting regular blood donation in volunteer donors. Autologous blood donors are requested to donate more frequently. To determine iron stores in autologous donors, 9 men and 10 women studied gave a total of 24 donations before their elective surgery (range 1-2 donations). All donors were tested for serum ferritin (SF) and hemoglobin (Hb) level. Iron supplements were taken by 88.89 per cent of men and 90 per cent of women. Mean SF before donations was 147.75 ng/mL in men and 53.19 ng/mL in women. After donations, mean SF decreased to 124.26 ng/mL in men and 38.81 ng/mL in women. None of them had depleted iron stores (SF < or = 15 ng/mL). In conclusion, iron supplementation was beneficial in maintaining body iron stores in autologous blood donors.

Iron stores in Thai blood donors.

A high number of blood donations may cause iron depletion. In order to evaluate iron stores in volunteer Thai blood donors, 82 male and 72 female donors were studied. All were tested for serum ferritin (SF), hemoglobin (Hb) level and asked for detailed histories of donations and iron supplementation. Mean SF in first-time donors was 161.12 ng/mL in men (n = 16) and 53.92 ng/mL in women (n = 23). Mean SF in multiple-time donors was 52.72 ng/mL in men (n = 66) and 25.72 ng/mL in women (n = 49). Depleted iron stores (SF < or = 15 ng/mL) were found in 8.7 per cent of first-time female donors, 21.21 per cent and 32.65 per cent of multiple-time male and female donors, respectively. The mean numbers of total donation were 51.42 +/- 30.8 in men and 8.22 +/- 6.97 in women. The estimation of depleted iron stores from Hb level could be determined in 57.14 per cent of male and 88.89 per cent of female donors. In conclusion, iron supplementation will benefit female donors and multiple-time male donors. The frequency of donations per year was more predictive of decreased iron stores than the number of total donations.