K. A. Dicke

Risk factors for acute graft‐versus‐host disease

Summary. Acute graft‐versus‐host disease (GvHD) is an important complication of bone marrow transplantation in humans. Risk factors are imprecisely defined and controversial. We analysed data from 2036 recipients of HLA‐identical sibling transplants for leukaemia or aplastic anaemia to identify risk factors for GvHD. Analyses indicate that grading of GvHD can be reproducibly divided into absent or mild versus moderate to severe; 2‐year actuarial probability was 54% (95% confidence interval 52–56%) for absent or mild and 46% (44–48%) for moderate to severe. Factors predictive of development of moderate to severe GvHD include donor/recipient sex‐match (female→male greater than others, relative risk 2.0, P<0.001). This risk was markedly increased if female donors for male recipients were previously pregnant or transfused (relative risk 2.9, P<0.0001). Older patients were at increased risk of GvHD (relative risk 1.6, P<0.001), but the age gradient was modest, even the youngest patients had a substantial risk of GvHD and, if parous or transfused female→male transplants were excluded, age was not a significant risk factor. Cyclosporine or methotrexate were equally effective at preventing GvHD and were superior to no prophylaxis (relative risk 2.3, P<0.01). These data should be useful in estimating the risk of acute GvHD in an individual patient and in designing clinical trials to investigate methods to modify or prevent GvHD.

TRANSPLANTATION OF BONE-MARROW CELLS AND FETAL THYMUS IN AN INFANT WITH LYMPHOPENIC IMMUNOLOGICAL DEFICIENCY

Abstract A 5-month-old male infant with lymphopenic immunological deficiency (Swiss-type agammaglobulinaemia) was treated by transplantation of a fetal thymus, and of bone-marrow-derived cells from his 7-year-old sister. The bone-marrow donor was selected for histocompatibility by leucocyte typing at the HLA locus and by mixed lymphocyte culture. Nucleated bone-marrow cells were centrifuged on an albumin gradient and a small number (5 × 10 6 /kg. body-weight) from the fraction assumed to contain concentrated haemopoietic stem cells, were transplanted. 3 months after the transplantation the boy resumed normal development, and the cellular and humoral immunity were restored. There was an increase in the three major classes of immunoglobulins to a level that exceeded normal adult values. In addition a homogenous IgG-L and an IgA-K band were detected in the serum. A temporary mild exanthema was taken to be a sign of graft-versus-host reaction. Nursing in a laminar-flow cabinet appeared to be relatively simple and highly effective for protection against contamination with microorganisms from the environment.

Risk factors for interstitial pneumonia following bone marrow transplantation for severe aplastic anaemia

Summary. Data from 547 patients with aplastic anaemia who received bone marrow transplants from HLA‐identical siblings were analysed to determine factors associated with the risk of interstitial pneumonia (IPn). IPn developed in 92 patients (17%). 37% of cases were associated with cytomegalovirus infection and 22% with other organisms: in 41% of cases no organism was identified. The case fatality rate was 64%; the mortality rate due to IPn was 11%. In multivariate analysis, four factors were associated with an increased probability of interstitial pneumonia: use of methotrexate rather than cyclosporine after transplantation (relative risk, 2.8: P<0.0008); occurrence of moderate to severe acute graft‐versus‐host disease (relative risk, 2.2; P<0.002); inclusion of total body radiation in the pretransplant preparative regimen (relative risk 2.2, P<0.004); and patient age >20 (relative risk 1.7, P<0.002). The probability of IPn ranged from 4% for patients with none of these adverse risk factors to 51% (relative risk of 13.4) for patients with all four. The incidence of IPn decreased significantly between 1978 and 1985, paralleling a decrease in the use of total body radiation pretransplant for immune suppression and methotrexate post‐transplant for prophylaxis against graft‐versushost disease.

The effect of pretreatment of allogeneic bone marrow graft recipients with antilymphocytic serum on the acute graft-versus-host reaction in monkeys

SUMMARY Short-term pretreatment of irradiated, bone marrow-treated monkeys with horse antilymphocyte serum (ALS) roughly doubles the survival time by decreasing the severity and delaying the onset of acute secondary disease in random host-donor combinations. It was found that (1) horse anti monkey serum does not interfere with the take and proliferation of the graft, and that (2) rabbit anti monkey serum acts less selectively, as shown by a high incidence of transplant failures. The absence of signs of stem cell toxicity in monkeys treated with horse ALS cannot be attributed to a lower degree of immunosuppression, because lower doses of rabbit ALS are as toxic as larger doses. The use of ALS for pretreatment of human bone marrow recipients is recommended, but, for the time being, only horse serum should be used. The effective dose of horse ALS for monkeys is in the order of 60 mg of IgG/ kg body wt/ day. Pretreatment for 2 days seems to be adequate

Transplantation of Haemopoietic Stem Cell (HSC) Concentrates for Treatment of Immune Deficiency Disease

De Vries et al. (1) advocated that combined immune deficiency (CID) could be ascribed to a primary defect of the pluripotent haemopoietic stem cell (HSC) instead of to a dysfunction of the thymus. A consequence of this new concept was that causal therapy could be expected from grafts of bone marrow derived from normal donors. Several of such grafts had been performed previously but without any beneficial results, instead in several of these cases severe acute graft versus host (GvH) had been encountered.(2) We realised that this complication was elicited by the grafted lymphocytes which are present in high numbers in bone marrow of primates (monkeys and man) (3). Therefore our efforts of treatment were aimed at grafting lymphocyte-free bone marrow cell suspensions preferably from HL A identical donors. This modified bone marrow therapy appeared to be highly successful (4). In the meantime it became evident that genotypical HL-A identity, although not being an absolute safeguard against GvH (5), decreases the chance of appearance, as well as the severity of this syndrome. Attempts were undertaken to restore also immunity by using lymphocyte -free bone marrow suspensions for mismatched donors.

Survival of patients with chronic myelogenous leukaemia relapsing after bone marrow transplantation: Comparison with patients receiving conventional chemotherapy

Treatment with busulphan and/or hydroxyurea rarely produces remission in patients with chronic myelogenous leukaemia (CML) in chronic phase. HLA‐identical sibling transplants almost always produce remission, and only about 20% of patients relapse post‐transplant. The increased anti‐leukaemic efficacy of transplants results from intensive pretransplant treatment and immune‐mediated anti‐leukaemia effects. We studied 433 patients surviving  2 years after diagnosis of CML to determine if patients who have relapsed after a transplant in chronic phase have longer survival from diagnosis than comparable subjects receiving chemotherapy. The chemotherapy cohort included 344 adults < 50 years of age treated on consecutive trials of the Italian Cooperative Study Group on CML between 1973 and 1986. The transplant cohort included 89 patients reported to the International Bone Marrow Transplant Registry who relapsed after an HLA‐identical sibling bone marrow transplant carried out between 1978 and 1992. Survivals in the two groups were compared using Cox proportional hazards regression to adjust for prognostic variables. Median survival was 65 months in the chemotherapy cohort and 86 months in the transplant cohort. The 7‐year probability (95% confidence interval) of survival was 34% (28–39%) in the chemotherapy cohort and 57% (43–70%) in the transplant cohort (P=0.003). There was no difference in survival of patients relapsing after T‐cell depleted and non‐T‐cell‐depleted transplants. We conclude that patients who relapse after an HLA‐identical sibling bone marrow transplant for CML in chronic phase have longer survival from diagnosis than comparable patients receiving chemotherapy. This effect is most likely to be the result of intensive chemotherapy and/or radiation given for pretransplant conditioning.

Konservierung von hämopoetischen Stammzellen

The CFU-S potential of mouse bone marrow, the transplantation capacity of autologous and allogeneic monkey bone marrow and the CFU-C potential of human bone marrow can be cryopreserved without loss of viability. It is critical for an optimal stem cell recovery to avoid an osmotic shock after thawing. The intracellular cryoprotectives glycerol and DMSO which provide a high osmotic pressure should be removed from the thawed cells by a slow stepwise dilution procedure.The CFU-S potential of mouse bone marrow, the transplantation capacity of autologous and allogeneic monkey bone marrow and the CPU-C potential of human bone marrow can be cryopreserved without loss of viability. It is critical for an optimal stem cell recovery to avoid an osmotic shock after thawing. The intracellular cryoprotectives glycerol and DMSO which provide a high osmotic pressure should be removed from the thawed cells by a slow stepwise dilution procedure. Das CFU-S-Potential von Mausknochenmark, das Transplantationspotential von autologem und allogenem Affenknochenmark sowie das CPU-C-Potential von menschlichem Knochenmark kann ohne Vitalitätsverlust eingefroren und wieder aufgetaut werden. Eine wichtige Voraussetzung für eine optimale Stammzellrecovery ist, daß die intrazellulären protektiven Substanzen Glycerin oder DMSO durch langsam stufenweise Verdünnung nach dem Auftauen entfernt werden, damit eine osmotische Schädigung der Zellen vermieden wird.

Allogene Knochenmarktransplantation Beim Menschen

Knochenmark besteht aus hamopoetischen Stammzellen (HSC) sowie Zellen der myeloiden, der erythroiden, der megakaryozytaren und der lymphoiden Linien; zusatzlich finden sich retikuloendotheliale Zellen. Definitionsgemas hat die HSC die Fahigkeit der identischen Reduplikation, d.h. die Fahigkeit, andere Stammzellen mit gleichen Eigenschaften zu produzieren, andererseits kann sie in eine der genannten vier Zellinien differenzieren. Nach intravenoser Applikation von Knochenmarkzellen (Knochenmarktransplantation) bei letal bestrahlten Empfangertieren ist es die HSC, die verantwortlich ist fur die Repopulation der hamopoetischen Organe, einschlieslich des lymphatischen Systems. Fur dieses Konzept spricht besonders die Tatsache, das das hamopoetische Gewebe letal bestrahlter Mause durch die Transplantation einer einzigen Milzkolonie (CFU-S) vollig repopuliert werden konnte (1). Derartige Zellkolonien in der Milz bestehen, wie man zeigen konnte, aus den Nachkommen einer einzigen hamopoetischen Stammzelle (2). Bis vor kurzem waren die morphologischen Eigenschaften der HSC unbekannt, vor allem deshalb, weil sie in geringer Zahl im Knochenmark vorkommt (0,2 – 0,4% der Knochenmarkzellen).