Tesis

Hubungan antara Saturasi Transferrin dan Ferritin Serum dengan Densitas Massa Tulang pada Penderita Dewasa dengan Thalassemia Beta yang Bergantung Transfusi = Correlation of Transferrin Saturation and Serum Ferritin with Bone Mass Densitometry in Adult Transfusion Dependent Beta Thalassemia Patients.

Latar Belakang: Muatan besi berlebih adalah kondisi yang akan terjadi pada penderita thalassemia yang bergantung transfusi. Muatan besi berlebih yang terjadi progresif akan menimbulkan kerusakan organ akibat toksisitas besi. Banyak ditemukan kelainan tulang pada penderita thalassemia seperti perawakan pendek, facies cooley atau fraktur spontan, tetapi sampai saat ini hanya sedikit penelitian yang secara khusus mencari efek toksisitas besi di tulang pada penderita thalassemia dewasa. Tujuan: Mengetahui peran toksisitas besi pada penurunan densitas tulang penderita thalassemia dewasa yang bergantung transfusi Metode: Studi potong lintang dilakukan terhadap penderita thalassemia mayor dan intermedia dewasa yang mendapat transfusi rutin di RSUPNCM Jakarta dari Agustus sampai Oktober 2016. Dilakukan pemeriksaan kadar besi yaitu saturasi transferrin (ST) dan ferritin serum, pemeriksaan Dual X-ray Absorbtiometry (DXA) untuk menilai densitas masa tulang (BMD) dan rontgen pelvis untuk menilai indeks femoral Singh. Analisis dilakukan untuk mengetahui korelasi antara ST atau ferritin dengan nilai BMD, korelasi antara indeks femoral Singh dengan BMD dan pencarian titik potong ST atau ferritin untuk membedakan densitas tulang rendah dan normal pada penderita thalassemia mayor dan intermedia dewasa dengan menggunakan receiver operating curve (ROC). Hasil: Sebanyak 60 penderita usia 18-68 tahun, 32% adalah penderita thalassemia mayor dan 68% adalah penderita intermedia dewasa yang mendapat transfusi minimal sekali tiap bulan dengan rerata Hb pre-transfusi sebesar 8.08mg/dL. Sebanyak 68% penderita memiliki densitas tulang rendah. Didapatkan nilai median ST 86% (20-112%), median dari rerata nilai ferritin setahun yaitu 3881 ng/mL (645-15437ng/mL), median nilai BMD terendah -1.1 (-5.7- -2.6). Didapatkan korelasi negatif secara bermakna antara ST dengan nilai BMD (r=0.329, nilai p=0.01), namun tidak didapatkan korelasi yang bermakna antara ferritin dengan nilai BMD (r=-0.088, nilai p=0.504) serta tidak ditemukan korelasi yang bermakna antara indeks femoral Singh dengan BMD (r=0.273, nilai p= 0.038). Kurva ROC, nilai ST didapatkan area dibawah kurva (AUC) 0.727 dengan titik potong ST 89.5% untuk membedakan densitas tulang rendah dan normal Kesimpulan: Kejadian densitas tulang rendah pada penderita thalassemia adalah sebesar 68%. Terdapat korelasi terbalik yang signifikan antara ST dan nilai BMD dengan nilai titik potong ST 89.5% untuk membedakan densitas tulang rendah dan normal pada thalassemia dewasa
Kata Kunci: Thalassemia, toksisitas besi, komplikasi organ, densitas tulang rendah.


Background: Iron overload is a complication experienced by transfusion dependent thalassemia (TDT) patients. Progressive iron accumulation results in tissue damage referred as iron toxicity. Bone deformities complication such as short stature, cooley’s face and fracture are also commonly found among TDT patients but only few studies has been conducted to evaluate the effect of direct iron toxicity in bone among such population. Objective: To determine the role of iron toxicity in low bone mass density among transfusion dependent thalassemia patients. Methods: Cross sectional study conducted among major and intermedia thalassemia patients whom regularly received blood transfusion in CiptoMangunkusumo Central Hospital Jakarta between August to October 2016. Level of transferrin saturation (TS) and ferritin were measured as indicator of body iron level while dual x-ray absorptiometry were measured to evaluate bone mass density (BMD) and pelvic X-ray to evaluate Singh femoral index. Statistical analysis were conducted to evaluate correlation between TS or ferritin to BMD, correlation between Singh index and BMD and to determine the best cutoff value of TS or ferritin to differentiate between normal to low bone mass density among TDT patients using receiver operating curve (ROC) Results: Total of 60 patients between 18-68 years old, 32% were thalassemia major patients, 68% were transfusion dependent thalassemia intermedia patients. Mean pre-transfusion HB were 8.08mg/dL, and as much as 68% subjects had low bone density. Median value of TS was 86% (20-112%), median value of ferritin was 3881ng/mL (645-15437ng/mL), median value of the lowest BMD score was 1.1 (-5.7- -2.6). Significant reverse correlation between BMD score and TS was found (r=-0.329 p value=0.01) but no correlation with ferritin (r=-0.088, p value= 0.504) nor correlation to Singh femoral index ((r=0.273, p value= 0.038). ROC curve analysis showed with area under the curve (AUC) 0,727, the best cutoff TS to differentiate normal to low bone density was 89.5% Conclusion: Low bone mass density is a common complication of thalassemia major and transfusion dependent thalassemia intermedia. Reverse correlation between BMD score and TS with cutoff value of TS 89.5% to to differentiate normal to low bone density
Keyword: Thalassemia, iron toxicity, complication, low bone density