Prognosis in acquired aplastic anaemia. A multivariate statistical analysis of 80 cases

Should we still use Camitta's criteria for severe aplastic anemia?

Background

The criteria by Camitta for diagnosis in severe aplastic anemia (SAA) has been used since 1976. However, there has been no attempt to verify the Camitta's criteria, that the survival in patients with SAA may differ by absolute neutrophil count (ANC), platelet count (PLT), and corrected reticulocyte count (CRC), which are components of the Camitta's criteria.

Methods

117 SAA patients diagnosed by the Camitta's criteria were analyzed, retrospectively. Univariate and multivariate analyses were used to evaluate the factors affecting overall survival (OS).

Results

Response by immunosuppressive therapy (IST) or stem cell transplantation (SCT) significantly affected OS (P=0.001). Therefore, we excluded treatment responders for analysis. Finally, 92 SAA patients including treatment non-responders by IST or SCT and conservative care group were analyzed by using univariate and multivariate analyses. The median age of analyzed patients was 54.5 years. Male to female ratio was 1:1. The median follow-up duration was 74.23 months (range, 54.71-93.74 months). The median ANC, PLT, and CRC were 394/µL, 12,000/µL, and 0.39%, respectively. In multivariate analyses, ANC <500/µL or ≥500/µL (P=0.015, HR 2.694, 95% CI: 1.20-6.01) and age (P=0.015, HR 1.022, 95% CI: 1.00-1.04) were the significant factors for OS.

Conclusion

ANC could be an essential, not an optional criterion for diagnosing SAA. This study suggests the possibility that the Camitta's criteria be modified. Studies in large cohorts are needed to transform the Camitta's criteria.

Predictors of response to immunosuppressive therapy with antithymocyte globulin and cyclosporine and prognostic factors for survival in patients with severe aplastic anemia

BACKGROUND

Immunosuppressive therapy (IST) with antithymocyte globulin (ATG) plus cyclosporine (CSA) is standard therapy in patients with severe aplastic anemia (SAA) who do not have an available HLA-matched sibling donor.

METHODS AND PATIENTS

The current study aimed to determine the predictive factors for response to IST in patients with SAA and to identify prognostic factors following IST. A total of 62 patients diagnosed with SAA who received IST with either rabbit ATG (n = 33) or horse ATG (n = 29) plus CSA between October 1994 and December 2007 were included.

RESULTS

With a median follow-up duration of 60.5 months, complete response and overall response were estimated to be 31% and 53%, respectively. The 4 yr overall survival rate was 75 + or - 6%. In terms of predicting the response to IST, neutrophil counts above 0.3 x 10(9)/L prior to IST were the only significant predictive factor (P = 0.02). Survival following IST was significantly different in favor of both the group showing high absolute reticulocyte counts (ARC) above 10.9 x 10(9)/L prior to IST (P = 0.004) and the group achieving any response following IST (P = 0.002).

CONCLUSIONS

Pre-IST neutrophil counts might predict the response to IST, while absolute ARCs prior to IST and response status after IST could be prognostic factors following IST.

Predicting response to immunosuppressive therapy and survival in severe aplastic anaemia

Horse anti-thymocyte globulin (h-ATG) and ciclosporin are the initial therapy for most patients with severe aplastic anaemia (SAA), but there is no practical and reliable method to predict response to this treatment. To determine whether pretreatment blood counts discriminate patients with SAA who have a higher likelihood of haematological response at 6 months to immunosuppressive therapy (IST), we conducted a single institution retrospective analysis on 316 SAA patients treated with h-ATG-based IST from 1989 to 2005. In multivariate analysis, younger age, higher baseline absolute reticulocyte count (ARC), and absolute lymphocyte count (ALC) were highly predictive of response at 6 months. Patients with baseline ARC > or = 25 x 10(9)/l and ALC > or = 1 x 10(9)/l had a much greater probability of response at 6 months following IST compared to those with lower ARC and ALC (83% vs. 41%, respectively; P < 0.001). This higher likelihood of response translated to greater rate of 5-year survival in patients in the high ARC/ALC group (92%) compared to those with a low ARC/ALC (53%). In the era of IST, the baseline ARC and ALC together serve as a simple predictor of response following IST, which should guide in risk stratification among patients with SAA.

Criteria for severe aplastic anaemia

To study the validity of currently accepted international criteria for severe aplastic anaemia, 213 consecutive cases of bone marrow aplasia from a single institution were analysed. The distribution percentiles of peripheral blood values and multivariate analysis showed that the current reticulocyte count limit of 1% (corrected for haematocrit) is inadequate an an indicator of severe disease and should be substantially lowered. Since the choice of treatment in aplastic anaemia may depend on the prognosis current criteria for severe aplastic anaemia should be modified.

A population study of severe aplastic anemia in children. Incidence, etiology and course

The total number of registered cases of severe aplastic anemia in Denmark was 39 among children aged 0-14 years in 1967 to 1982 giving an annual incidence of 2.2 cases per 1 million children in a well defined and stable population. A probable cause of the aplastic anemia was found in 21 cases (54%). Exposure of the population to known etiological factors of aplastic anemia such as chloramphenicol, pesticides and hepatitis was constant in the study period, and accounted for 2, 5, and 2 cases, respectively. Other infections caused 6 cases, other drugs 2 cases, and organic diluents one case. Three children with constitutional aplasia developed severe aplastic anemia among a total of 6 Fanconi's anemias, 3 probable Fanconi's anemias, and 10 cases of erythrogenesis imperfecta diagnosed during the same 16 years. Thirteen patients (33%) died within 3 months after the diagnosis while on supportive treatment and low dose prednisolone supplemented with androgen treatment. Long term survival occurred in 10 patients (26%), of which 5 patients were in complete and 5 in partial remission.

Comparison between bone marrow transplantation and antithymocyte globulin in treatment of young patients with severe aplastic anemia

Fifty-seven patients younger than 25 years with severe aplastic anemia underwent either bone marrow transplantation or antithymocyte globulin therapy (ATG) to ascertain which approach should be used in young patients. Thirty-five patients who had an HLA-identical sibling donor underwent bone marrow transplantation after conditioning with cyclophosphamide and low-dose total-body radiation. Twenty-two patients who did not have an HLA-identical donor received ATG. The 2-year actuarial survival of patients after transplant is 72% (95%, CI 64% to 80%), versus 45% (95%, CI 29% to 61%) in those given ATG therapy (P = 0.18). In those patients surviving 6 months after treatment, return of peripheral blood counts to normal values was more common in patients who received marrow transplant compared with those given ATG therapy (P less than 0.001). Furthermore, 24 of 26 transplant survivors had Karnofsky performance scores greater than 90%, compared with only five of 13 ATG survivors. These data suggest that bone marrow transplantation is the preferred therapy for severe aplastic anemia in young patients who have an HLA-identical sibling donor. ATG should be reversed for those young patients with severe aplastic anemia who do not have a histocompatible marrow donor.

Prediction of survival in adults with acquired Bi- or pancytopenia

In a retrospective study of 44 adults with acquired bi- or pancytopenia without evidence of any causal disorder, the survival curve suggested the existence of a subgroup of short survivors, mainly with aplastic anaemia, with death within 4 months. The initial values of 14 single clinical, blood and bone marrow variables were significantly associated with survival less than 4 months. Stepwise multiple logistic regression analyses identified 2 combinations of variables displaying significant simultaneous associations with short survival: (i) increased % of non-myeloid bone marrow cells and haemorrhagic manifestations initially; (ii) increased % of non-myeloid marrow cells, circulating erythroblasts and no history of any drug exposure. The predictive capacities of a resulting estimate of the probability of short survival and of previously introduced prognostic indices were approximately equal. The frequency of a correct prediction of a survival shorter than 4 months was in the range of 0.71-0.78 and that of longer survival in the range of 0.74-0.94.