Beibei Yang1,†, Dongmei Liu1,†, Changyu Yang1, Yali Zhou1, Guiping Liao1, Jian Huang1, Yingying Li1, Yinjiang Tang2 and Xiaolin Yin1.
1
Department of Hematology, The 923rd Hospital of the Joint Logistics
Support Force of the People's Liberation Army, Nanning, Guangxi, China.
2 Department of Pulmonary Vascular and General Medicine, Fuwai Yunnan Cardiovascular Hospital, Kunming, Yunnan, China.
† These authors have contributed equally to this work.
.
Correspondence to:
Yinjiang Tang, Department of Pulmonary Vascular and General Medicine,
Fuwai Yunnan Cardiovascular Hospital, Kunming, Yunnan, CHINA; E-mail: tangyinjiang1@126.com.
Xiaolin
Yin, Department of Hematology, The 923rd Hospital of the Joint
Logistics Support Force of the People's Liberation Army, Nanning,
Guangxi, CHINA; E-mail: yin-xl@163.com.
Published: September 01, 2025
Received: June 11, 2025
Accepted: August 11, 2025
Mediterr J Hematol Infect Dis 2025, 17(1): e2025059 DOI
10.4084/MJHID.2025.059
This is an Open Access article distributed
under the terms of the Creative Commons Attribution License
(https://creativecommons.org/licenses/by-nc/4.0),
which permits unrestricted use, distribution, and reproduction in any
medium, provided the original work is properly cited.
|
To
the editor
Thalassemias
are a group of inherited hemoglobinopathies caused by mutations in the
α-globin or β-globin gene clusters, leading to impaired hemoglobin
synthesis and imbalanced globin chain production, which have a
significant prevalence in many countries, including China.
β-thalassemia is characterized by an excess of α-globin chains and
insufficient β-globin, leading to ineffective erythropoiesis and
hemolysis. This results in chronic hemolytic anemia, ineffective
erythropoiesis, and complications including iron overload, bone
deformities, and growth impairment.[1] Based on
transfusion dependence, β-thalassemia is classified into two clinical
phenotypes: transfusion-dependent thalassemia (TDT), which requires
lifelong regular red blood cell transfusions for survival, and
non-transfusion-dependent thalassemia (NTDT), which does not require
regular transfusions but may need occasional transfusions due to
infections or stressors. TDT is predominantly associated with iron
overload (affecting >80% of adults), endocrine disorders (e.g.,
hypogonadism, diabetes; 40-60% prevalence), and transfusion-transmitted
infections, driven by chronic transfusions. Cardiac iron overload
remains a leading cause of mortality. NTDT more frequently involves
extramedullary hematopoiesis (≥50% of patients), thrombotic events
(e.g., stroke; 10-30%), leg ulcers, and pulmonary hypertension (PAH),
primarily due to chronic hemolysis and hypercoagulability. Splenectomy
further elevates thrombosis risk. PAH represents a spectrum of diseases
increasingly recognized as a major source of morbidity and mortality
across various conditions. Elevated pulmonary arterial pressure (PAP)
exerts strain on the right ventricle, which can ultimately progress to
right ventricular failure and death.[2] Moreover, the
development of PAH in thalassemia is known to result from
multifactorial mechanisms, including chronic hemolysis, iron overload,
hypercoagulability, and alterations in circulating cells following
splenectomy. The prevalence of PAH in β-thalassemia patients, as
confirmed on right heart catheterization, was 2.1%,[3]
with higher rates observed in NTDT and post-splenectomy patients. Data
on the use of pulmonary vasodilators in β-thalassemia are limited. The
4-year mortality rate of PAH in β-thalassemia is as high as 54.2%.[4]
Luspatercept has been shown to increase hemoglobin levels in
β-thalassemia by promoting the differentiation and maturation of
late-stage red blood cell precursors.[5] Given the
poor prognosis and treatment challenges associated with PAH in
β-thalassemia, this paper reports on the impact of luspatercept
treatment on a patient with β-thalassemia and PAH.
Case
We
present the case of a 33-year-old Chinese man diagnosed with
β-thalassemia at the age of 1. He has been receiving intermittent
transfusion therapy and regular iron-chelating therapy since the age of
30. His genotype is CD17(A〉T)/βE, and he underwent splenectomy at age
11. Due to limited blood resource availability in the local healthcare
system during the early treatment phase, which constrained consistent
transfusion access, he received occasional transfusions every 6-10
months to maintain his hemoglobin levels at 70-80 g/L. From age 30, he
also received daily iron-chelating therapy using Deferasirox (30
mg/kg/d). He was considered a NTDT patient.
In February 2022, at
age 31, he experienced chest discomfort and shortness of breath
following physical activity, which resolved with rest. He was admitted
to a cardiovascular hospital where initial tests revealed the
following: white blood cell count (WBC) 11.29×10^9/L, hemoglobin (Hb)
75 g/L, platelet count (PLT) 671×10^9/L, nucleated red blood cell count
(NRBC) 11.03×10^9/L, serum ferritin (SF) 1238.7 ng/mL, prothrombin time
(PT) 14.8 s, and D-dimer 0.33 µg/mL. Liver function tests showed total
bilirubin (TBil) 102.12 µmol/L, indirect bilirubin (IBil) 80.95 µmol/L,
and lactic dehydrogenase (LDH) 174 U/L. Echocardiography demonstrated
mild tricuspid regurgitation, with a tricuspid regurgitation jet
velocity (TRV) of 3.4 m/s and an estimated pulmonary artery systolic
pressure of 51 mmHg. Pulmonary function tests showed moderate to severe
restrictive ventilatory dysfunction; small airway dysfunction;
pulmonary diffusing capacity was moderately decreased, and
bronchodilation tests were negative. Contrast-enhanced CT of the
pulmonary arteries results showed no evidence of embolism in the
segmental and proximal pulmonary arteries, and pulmonary artery
dilatation is present. Right heart catheterization (Table 1)
results showed pulmonary artery pressure (PAP) 57/31/43mmHg, pulmonary
vascular resistance (PVR) 3.24 Wood U, and pulmonary artery wedge
pressure (PAWP) 13mmHg, which indicated PAP and PVR, with a decreased
PAWP, suggesting precapillary pulmonary hypertension. His 6-minute walk
test (6MWT) recorded 356 meters.
 |
- Table 1. Right heart catheterization results.
|
The
patient was diagnosed with PAH and was treated with spironolactone for
diuresis and digoxin to enhance cardiac function. Additionally, he
received low-dose Riociguat (0.5 mg three times daily) to lower
pulmonary artery pressure due to the following treatment-emergent
headache. After approximately three months on this regimen, his
condition showed no significant improvement. In June 2022, the 6MWT was
350 meters. Echocardiography demonstrated mild tricuspid regurgitation,
with a TRV of 3.3 m/s and an estimated pulmonary artery systolic
pressure of 49 mmHg.
Luspatercept was approved by China’s
National Medical Products Administration (NMPA) in 2022 for the
treatment of adult patients with β-thalassemia who require regular red
blood cell transfusions and do not have contraindication in PAH. Then,
the patient began receiving Luspatercept at 1mg/kg every 21 days, and
after two months, the dose was adjusted to 1.25mg/kg every 21 days. In
July 2022, the magnetic resonance imaging (MRI) results indicated
Cardiac T2* MRI: 46.89 ms (normal >20 ms); Liver iron concentration:
>14 mg/g dw (Severe overload). Figures 1 show the changes in serum ferritin and hemoglobin levels following the Luspatercept therapy. Figures 2
show the changes in the Echocardiogram before and after treatment with
Luspatercept. The patient reported improved chest discomfort and
shortness of breath after the second dose of Luspatercept. 2 months
after receiving Luspatercept, he followed up with the hematological
index (Table 2), indicating
increased HB, decreased SF, and improved hemolysis markers (bilirubin
and NRBC). At 14 and 21 months of follow-up, improvements were
maintained, and echocardiography showed normal TRV (Table 2).
After improving significantly, the patient enhanced their motivation to
seek further treatment. This improvement in compliance, combined with
the family’s efforts to identify alternative blood supply sources,
eventually enabled more consistent transfusions. In April 2024, after
detailed counseling, the patient made an informed decision to
discontinue luspatercept treatment in order to enroll in a potentially
curative gene therapy clinical trial, requiring
≥8-week washout of erythroid-active agents. An
echocardiogram at the cardiovascular hospital in August 2024 revealed
mild tricuspid regurgitation, with a TRV of 3 m/s and an estimated
pulmonary artery systolic pressure of 41 mmHg.
 |
Figure 1. The change in hemoglobin and serum ferritin after Luspatercept.
In July 2022, the patient began receiving Luspatercept at 1mg/kg every
21 days, and after two months, the dose was adjusted to 1.25mg/kg every
21 days. He received daily iron-chelating therapy using Deferasirox (30
mg/kg/d) from September 2022. He received occasional transfusion
therapy every 6-10 months during the early treatment phase, and he has
maintained a bimonthly transfusion therapy since September 2023. |
 |
Figure 2. Patient’s Echocardiogram before and follow-up after treatment with Luspatercept.
(a) Presented the patient's Echocardiogram prior to Luspatercept
treatment, showing a tricuspid regurgitation jet velocity of 3.32 m/s,
a tricuspid valve pressure gradient of 44.16 mmHg, and an estimated
pulmonary artery systolic pressure of 49 mmHg; (b) Presented the
patient's Echocardiogram 21 months after Luspatercept treatment,
showing a tricuspid regurgitation jet velocity of 2.09 m/s, a tricuspid
valve pressure gradient of 17.47 mmHg, and an estimated pulmonary
artery systolic pressure of 17 mmHg.
|
 |
Table 2. Patient’s data before and follow-up after treatment with Luspatercept.
|
Discussion
Based
on the patient's Echocardiogram and Contrast-enhanced CT of the
pulmonary arteries, pulmonary hypertension secondary to left heart
disease, pulmonary hypertension associated with hypoxia, or pulmonary
artery obstruction due to lung disease has been excluded. PAH secondary
to β-thalassemia is classified under Group 5 pulmonary hypertension
(PH), encompassing disorders with multifactorial and incompletely
understood mechanisms.[6] The presented case
highlights a splenectomized patient with β-thalassemia exhibiting
hallmark features of chronic hemolysis, iron overload, platelet
activation, and hypercoagulability - all recognized risk factors for
PAH progression.
Conventional management of
β-thalassemia-associated PAH centers on transfusion regimens, iron
chelation therapy, and supportive measures such as oxygen
supplementation, anticoagulation, and cardiac function optimization.[7] According to current ESC/ERS PH Guidelines,[8]
Sildenafil, bosentan, and other similar drugs are primarily indicated
for pulmonary arterial hypertension (Group 1). However, no prospective
studies have confirmed their efficacy in treating pulmonary arterial
hypertension caused by thalassemia (Group 5). Despite these
interventions, pulmonary vasodilators - including phosphodiesterase
type 5 inhibitors (PDE-5i), endothelin receptor antagonists, and the
soluble guanylate cyclase stimulator riociguat - demonstrated limited
efficacy and unfavorable adverse effect profiles in this patient.[7] Notably, three months of low-dose riociguat failed to ameliorate symptoms or objective measures of PAH.
The
1.25 mg/kg dose of Luspatercept elicited a hemoglobin elevation of
approaching 10 g/L, confirming its therapeutic efficacy for anemia
management.[9] Intriguingly, concurrent enhancements
in 6-minute walk test (6MWT) performance and tricuspid regurgitant
velocity (TRV) on echocardiography suggested a rapid reduction in
pulmonary vascular resistance. Discontinuation of luspatercept
precipitated increased transfusion requirements and recrudescence of
pulmonary hypertension, underscoring its therapeutic dependency.
Hematologic profiling revealed diminished nucleated red blood cell
(NRBC) counts post-treatment, indicative of attenuated ineffective
erythropoiesis - a finding potentially linked to PAH mitigation, though
mechanistic clarity remains elusive. We acknowledge that this
confounding factor (concurrent transfusions) may complicate the
interpretation of luspatercept’s isolated effects on PAH. However, the
temporal association between luspatercept initiation and symptomatic
improvement (prior to transfusion intensification) suggests a potential
role of the drug, warranting further investigation in controlled
settings.
In chronic hemolytic anemia, PAH pathogenesis is driven
by nitric oxide (NO) depletion due to free hemoglobin-mediated
scavenging, compounded by L-arginine metabolic dysregulation,
endothelial dysfunction, and elevated endothelin-1 levels.[10] The phase 3 COMMANDS trial[11]
further supports luspatercept’s cardioprotective role, demonstrating
reduced NT-proBNP levels, likely mediated via TGF-β signaling
suppression, apoptotic pathway modulation, and downregulation of
pro-inflammatory mediators.[12,13] These effects may
synergistically enhance NO bioavailability, offering a plausible
pathway for PAH alleviation. Meantime, a phase II, open-label study of
sotatercept revealed that sotatercept reduced transfusion requirements
in TDT patients.[14] By sequestering SMAD2/3 pathway
ligands (e.g., activins, growth differentiation factors), sotatercept
restores balance between pro-proliferative and anti-proliferative
signaling in the pulmonary vasculature.[15] Its efficacy in PAH is evidenced by a phase 3 trial showing superior 6MWT outcomes versus placebo (p<0.001).[16] As a similar agent to luspatercept,[17]
which has demonstrated effectiveness in treating PAH in thalassemia in
this case, the potential efficacy of sotatercept in PAH in thalassemia
(classified under Group 5) is worth exploring.
β-thalassemia-related
PAH confers significant mortality risk, yet pharmacologic interventions
- particularly those achieving >25% hemodynamic improvement - may
attenuate this burden.[4] In this case, luspatercept
yielded dual hematologic and cardiopulmonary benefits, suggesting a
novel role in modulating pulmonary vascular resistance. With
symptomatic relief improving compliance, the patient could maintain
transfusion regimens more effectively, thereby meeting the eligibility
criteria for experimental gene therapy as a potential cure. While
preliminary, these observations warrant rigorous investigation to
delineate luspatercept’s pleiotropic effects and optimize therapeutic
strategies in this high-risk population. At the same time, based on the
role of microthrombotic events in the evolution of PAH in thalassemia,
an increase in the thrombotic risk may become evident in the long-term
use of luspatercept and must be promptly recognized.
Author Contributions
Xiaolin Yin,
Yinjiang Tang, and Beibei Yang contributed to the design and data
acquisition. Beibei Yang and Dongmei Liu contributed to the data
analysis, discussion, and manuscript writing. Dongmei Liu and Changyu
Yang contributed to imaging data acquisition and data analysis. Yali
Zhou and Guiping Liao contributed to data acquisition. Jian Huang and
Yingying Li contributed to scheduling patient follow-ups. All authors
reviewed the manuscript.
Data Availability Statement
The data are available from the corresponding author upon reasonable request.
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