| خلاصه مقاله | Introduction: The most common indication of allogeneic HSCT include myelodysplastic syndromes, and in the case of autologous HSCT, multiple myeloma, lymphomas, and leukemias. The main target for effective hematopoiesis is engraftment after HSCT, which is the most important criterion for long-term survival. Engraftment is the process by which HSC cells in the BM find their way to proliferate and produce all hematopoietic subcellular cells. Neutrophil engraftment (NE) is equivalent to the first day of three consecutive days when neutrophil counts reach above 500 × 106 / L (ANC> 500) and platelet engraftment (PE) is considered equivalent to the first day of three consecutive days when the platelet count reaches > 20 × 109 / L, provided that the patient has not received platelets in the last seven days. Thyroid dysfunction is usually one of the most late-onset complications of allogeneic HSCT, therefore long-term follow-up of thyroid function tests is recommended.
Materials and Methods: This cross-sectional analytical study was performed on 37 transplanted patients to investigate the relationship between TFT before autologous and allogeneic HSCT and the time to achieve NE and PE. All patients had normal TSH, T3, and T4 tests three days before HSCT. They were clinically euthyroid, and examination of the patients' thyroid tissue was normal. The normal range of the TSH test was 0.32-5.45 with mean: 2.89, Free T3: 1.98 (1.4-4.2) with mean: 2.8, and Free T4: 1 (0.8-2) with mean: 1.4 based on ELISA. After HSCT, CBC-H1 was checked daily, and after the first day of ANC> 500 × 106 / L, if the neutrophil count remained >500 × 106 / L for 3 consecutive days, the first day of ANC500 was considered as NE, and PE was considered as the first day of 3consecutive days when the platelet counts reach > 20 × 109 / L.
Results: An OR>6 was observed in the probability of time to NE>10 days in patients with TSH>2.89 in the UNR and male patients, also in the probability of time to PE>15 days in patients with TSH>2.89 mU/L in the UNR. Statistically significant p-value and CI was found in the probability of time to NE>10 days in male patients (OR=8.58,P-value=0.036) and time to PE>15 days in patients with TSH>2.89 in the UNR (OR=14.32,P-value=0.041). Based on additional backward-elimination multiple logistic regression, disease type(OR=2.14,P-value=0.354) and gender (OR= 5.53,P-value= 0.030) were the best predictors of reaching NE, while TSH level (OR=10.70,P-value=0.048) and T3 (OR=0.20,P-value=0.102) were the best predictors of reaching PE.
Conclusions: Low dose levothyroxine can be cautiously recommended to achieve TSH to ≤2.8 in the LNR before performing HSCT in euthyroid patients, which will reduce the times to NE and PE, cause earlier discharge of patients, as well as will be the prophylactic treatment of possible future HSCT-induced hypothyroidism. Future clinical trials will require comparing two subgroups with and without supplementary levothyroxine treatment to rejection or approval of this replacement hormonal therapy. |