The value of crossmatch tests and panel tests as a screening tool to predict the outcome of platelet transfusion in a non-selected haematological population of patients

Correlation of platelet crossmatch results by Solid Phase Red Cell Adherence Assay (SPRCA) with post-transfusion platelet count increment in adult hemato-oncology patients of a tertiary care oncology centre in India

AIMS

To assess platelet crossmatch result by SPRCA and find its correlation with post-transfusion platelet count increment among adult hemato-oncology patients.

METHODS

A prospective observational pilot study of 50 adult hematologic malignancy patients previously transfused, but not already known to be transfusion-refractory and without any nonimmune causes for inadequate response to platelet transfusion were included after obtaining informed consent. They were transfused one unit of ABO identical single donor platelet. Ten minutes to 1 -h post-transfusion CCI was calculated. CCI ≥ 7500 was considered as adequate response. Post-transfusion crossmatching by SPRCA was performed by using preserved platelet samples from donor units with the serum of the respective patient. Statistical analysis of the correlation between platelet crossmatch results and CCI was done.

RESULTS

Out of 50 crossmatches, 78% (39/50) showed compatible and 22% (11/50) showed incompatible results. Among 39 compatible results, 87.2% (34/39) showed adequate CCI and 12.8% (5/39) showed inadequate CCI. Among 11 incompatible results, 18.2% had adequate CCI and 81.8% had inadequate CCI. The difference between the response in terms of CCI to compatible and incompatible crossmatches was found to be statistically significant (p < 0.05). Other variables like age, sex, number of previous transfusions and underlying clinical condition of the patient were not found to have any effect on the compatibility of crossmatch.

CONCLUSIONS

Transfusion of crossmatched platelets to non-refractory, multiply transfused hematological malignancy patients without serious illness might provide a small benefit over transfusing randomly selected platelets, though these data must be confirmed with a larger sample size.

Cross-match-compatible platelets improve corrected count increments in patients who are refractory to randomly selected platelets

BACKGROUND

Cross-match-compatible platelets are used for the management of thrombocytopenic patients who are refractory to transfusions of randomly selected platelets. Data supporting the effectiveness of platelets that are compatible according to cross-matching with a modified antigen capture enzyme-linked immunosorbent assay (MAC-ELISA or MACE) are limited. This study aimed to determine the effectiveness of cross-match-compatible platelets in an unselected group of refractory patients.

MATERIALS AND METHODS

One hundred ABO compatible single donor platelet transfusions given to 31 refractory patients were studied. Patients were defined to be refractory if their 24-hour corrected count increment (CCI) was <5×10(9)/L following two consecutive platelet transfusions. Platelets were cross-matched by MACE and the CCI was determined to monitor the effectiveness of platelet transfusions.

RESULTS

The clinical sensitivity, specificity, positive predictive value and negative predictive value of the MACE-cross-matched platelets for post-transfusion CCI were 88%, 54.6%, 39.3% and 93.2%, respectively. The difference between adequate and inadequate post-transfusion 24-hour CCI for MACE cross-matched-compatible vs incompatible single donor platelet transfusions was statistically significant (p=0.000). The 24-hour CCI (mean±SD) was significantly higher for cross-match-compatible platelets (9,250±026.6) than for incompatible ones (6,757.94±2,656.5) (p<0.0001). Most of the incompatible cross-matches (73.2%) were due to anti-HLA antibodies, alone (55.3% of cases) or together with anti-platelet glycoprotein antibodies (17.9%).

DISCUSSION

The clinical sensitivity and negative predictive value of platelet cross-matching by MACE were high in this study and such tests may, therefore, be used to select compatible platelets for refractory patients. A high negative predictive value demonstrates the greater chance of an adequate response with cross-matched-compatible platelets.

Absolute immature platelet count may predict imminent platelet recovery in thrombocytopenic children following chemotherapy

BACKGROUND

Immature platelets are the youngest circulating platelets and they reflect the rate of thrombopoiesis. The immature platelet fraction (IPF) or the absolute immature platelet count (AIPC) may predict platelet count recovery following chemotherapy-induced thrombocytopenia in pediatric patients and help guiding prophylactic platelet transfusion therapy.

PROCEDURE

To test IPF and AIPC as predictors of platelet recovery, 19 children with platelet nadirs of less than 20 × 10(9)/L after chemotherapy were prospectively enrolled. IPF, platelet count, and C-reactive protein (CRP) were analyzed in 416 paired samples from 37 patients with malignancies to test if IPF-levels were CRP dependent.

RESULTS

A significant increase of 0.6 × 10(9)/L in AIPC was seen between 1 and 2 days prior to platelet count recovery. No predictive day-to-day differences were found for IPF. Platelet count recovery did not occur significantly earlier for patients with a peak IPF > 10% than for those patients with a peak IPF < 10%. IPF and AIPC showed no correlation to CRP. AIPC was in contrast to IPF not influenced by platelet transfusions.

CONCLUSION

AIPC increased significantly between 24 and 48 hours before platelet recovery whereas IPF showed no significant increase during the same time period. AIPC may be a better indicator than IPF for predicting platelet recovery after chemotherapy in pediatric patients.