You will be provided with the titles and abstracts of a collection of medical RCT reports studying a clinical question -- for instance, the efficacy of an intervention on some medical outcome. Please write a few sentences synthesizing the findings of these reports, which could serve as a conclusion section for a systematic review article. Your response should not include any other text. The RCT reports are below.



Title 1:
Filtration leukapheresis for granulocyte transfusion therapy. Clinical and laboratory studies.
Abstract 1:
To study the clinical efficacy of granulocytes obtained by filtration leukapheresis, patients with clinically evident infection and granulocyte counts of smaller than 500 per cubic millimeter were randomly assigned to receive conventional therapy alone or with a granulocyte transfusion obtained from a single donor each day for four days. Five of 19 control patients survived to day 20, and 15 of 17 in the transfused group survived. Comparison of the two populations for variables such as age, disease, and severity and type of infection revealed no other factor that could account for the difference in survival. Outcome was not demonstrated to be related to HL-A match, post-transfusion counts, or presence of leukocyte antibodies. Functional studies of granulocytes obtained by filtration leukapheresis showed only minor differences although appearance was altered. Granulocytes so obtained can be used safely and efficaciously as adjunctive therapy for infection associated with granulocytopenia.


Title 2:
A controlled study of the efficacy of granulocyte transfusions in patients with neutropenia.
Abstract 2:
A randomized clinical trial to determine the efficacy of granulocyte transfusions in neutropenic patients with infection was conducted. Criteria for patient selection included a proved infection, a granulocyte count of less than 300/mm3, availability of a suitable donor and failure to respond to at least 72 horus of appropriate antibiotic therapy. Thirty patients were assigned at random to receive either granulocyte transfusions or to serve as a control group. Antibiotic therapy was continued in both groups. Responses were judged by the degree of diminution of infectious episodes and survival. The results showed that 11 of 13 control patients failed to respond during the period of observation, whereas 10 of 17 patients given transfusions responded. The results were statistically significantly different (p less than 0.05). The median survival was 22.5 days in the group given transfusions (group 2) and 7.7 in the control group (group 1) (p less than 0.01). The granulocyte transfusions were most effective in patients with hypocellular marrows who failed to recover during the period of observation. These results indicate that granulocyte transfusions are effective in the short-term control of infections in neutropenic patients.


Title 3:
Pulmonary complications in patients receiving granulocyte transfusions and amphotericin B.
Abstract 3:
To evaluate the possibility that in febrile granulocytopenic patients amphotericin B given along with granulocyte transfusions could increase the incidence of pulmonary complications, we studied 43 severely granulocytopenic patients during 46 episodes of fever. Granulocytes were administered as part of the clinical protocol to all 19 patients who had clinically or microbiologically documented infection; the other 24 patients were randomly allocated to treatment with granulocytes (13 patients) or without granulocytes (11 patients). In all, 32 patients received granulocyte transfusions during 35 episodes of fever. Pulmonary complications developed in six patients in each of the two randomized groups. The incidence of pulmonary complications was not influenced by the number of granulocyte transfusions or by the number of granulocytes per transfusion. Pulmonary complications were significantly more likely to occur in patients with fungal infections. Amphotericin B was given according to clinical indications; 21 patients in all received it. Survival was significantly poorer in patients with pulmonary complications, but the administration of amphotericin B was not related either to survival or to the incidence of pulmonary complications. We conclude that pulmonary complications and poor prognosis are related to underlying pulmonary fungal infection and not to any interaction between amphotericin B and granulocyte transfusions.


Title 4:
A randomized clinical trial of granulocyte transfusions for infection in acute leukemia.
Abstract 4:
In a prospective, controlled, randomized study to evaluate the efficacy of filtration-leukapheresis granulocytes in granulocytopenic, febrile patients with leukemia, 19 patients received antibiotics alone, and 12 received antibiotics plus daily granulocyte transfusions from ABO-matched donors. In skin-chamber studies the granulocytes appeared at sites of inflammation for at least six hours after transfusion. Infected subjects survived longer if they received granulocytes. Differences between control and transfused patients were greatest in patients with persistent bone-marrow failure, the 21-day survival being 20 per cent in controls, and 75 per cent in transfused patients. Granulocytes appeared to have no effect on the outcome of febrile episodes in which infection was not documented, the 21-day survival being 79 per cent for controls and 88 per cent for transfused patients. The transfusion of granulocytes thus appears to offer a survival advantage to infected, persistently granulocytopenic patients.


Title 5:
Therapeutic granulocyte transfusions for documented infections. A controlled trial in ninety-five infectious granulocytopenic episodes.
Abstract 5:
Patients with granulocytopenia (granulocyte count less than 0.5 x 10(9)/L) and a documented infection were randomized to receive or not to receive daily granulocyte transfusions in addition to antimicrobial therapy. Thirty-four of 47 control patients responded to therapy compared to 30 of 48 transfused patients (type 2 error, pneumonia, or a soft tissue infection, respective response rates for the control and transfused patients were 11 of 11 and 11 of 16 (Yates' corrected chi-squared test, p = 0.12). Response rates for patients with gram-negative septicemia were lower but were influenced by recovery of bone marrow function. Eleven of 12 control patients and seven of seven transfused patients with recovery of marrow function survived the gram-negative septicemia. In contrast, 12 of 24 control patients and 12 of 25 transfused patients survived gram-negative septicemia and persistent granulocytopenia (type 2 error p = 0.13). Two thirds of all fatal infections were associated with an underlying disease refractory to medical therapy. Therapeutic granulocyte transfusions had no substantial benefit over optimal antimicrobial therapy alone in managing infected patients with granulocytopenia.


Title 6:
[Granulocyte substitution in febrile leukemia patients with bone marrow aplasia. 1. Results of a prospective study].
Abstract 6:
A prospective, randomized study was performed in aplastic, granulocytopenic, infected patients with acute leukemia during induction therapy. 12 patients received antibiotics alone, and 13 received antibiotics plus 1.7-14.7 X 10(10) (MEAN 6.6 X 10(10) granulocytes by 1-5 (mean 2.7) daily transfusions. In 10 of 12 controls the infection resolved and remission was achieved with granulocyte counts greater than 500/mm3 15 +/- 9 days after randomization. In the transfused patients, infection was brought under control in 10 out of 13 and remission was achieved with granulocyte counts greater than 500/mm3 25+/- 11 days after randomization. Only one death due to infection was observed (6 days after randomization, control).
Currently, there is inconclusive evidence from RCTs to support or refute the generalised use of granulocyte transfusion therapy in the most common neutropenic patient populations, that is caused by myeloablative chemotherapy with or without haematopoietic stem cell support. Contemporary well designed prospective trials are required to evaluate the efficacy of this intervention in these patient populations and to establish definitively whether it has clinical benefit. In such studies, average numbers of collected granulocytes for adults should be (at least) greater than 1x1010.