Molecular Hydrogen Therapy in Sjögren’s Syndrome With Pulmonary Arterial Hypertension and Right-sided Heart Failure: A Case Report of Improved Immune Markers Including Treg, B Cells and Plasma Cell

Abstract

Background/Aim

Connective tissue disease-associated pulmonary arterial hypertension (CTD-PAH) is a severe complication characterized by elevated pulmonary artery pressure, which can lead to right heart failure and death, if untreated. Standard treatments often fail to adequately manage symptoms, highlighting the need for novel therapeutic approaches. This study investigated the efficacy of molecular hydrogen (H₂) therapy in a patient with CTD-PAH.

Case Report

We present the case of a 56-year-old female with CTD-PAH, diagnosed in 2013 with Sjogren’s syndrome complicated by interstitial lung disease (ILD) and PAH. Despite treatment with sildenafil, bosentan, macitentan, iloprost, and corticosteroids, her condition deteriorated, resulting in severe dyspnea and cardiogenic shock in 2020. In May 2023, molecular hydrogen therapy was initiated as an adjuvant treatment. The patient received daily hydrogen capsules, which led to increased CD127+ Treg cells, reduced anti-Ro antibodies, and decreased B cell subsets. Her clinical symptoms stabilized without adverse effects.

Conclusion

This case highlights the potential benefits of molecular hydrogen therapy in CTD-PAH. H₂ therapy exhibiting anti-inflammatory and immunomodulatory effects, leading to improved immune cell profiles and stabilizing clinical symptoms in a patient unresponsive to conventional treatments. Further research is needed to elucidate the mechanisms of H₂ therapy and validate its efficacy in larger cohorts. Molecular hydrogen therapy shows promise as a safe adjunctive treatment for CTD-PAH, offering a new approach for managing this challenging condition.

Connective tissue disease-associated pulmonary arterial hypertension (CTD-PAH) presents significant challenges in clinical management due to its complex pathogenesis and potential life-threatening consequences if left untreated (1). Among the various connective tissue diseases (CTDs) implicated, Sjogren’s syndrome stands out as a notable contributor to CTD-PAH (2). PAH, characterized by elevated pressure in the pulmonary arteries, poses a risk of right heart failure and increased mortality if left untreated (3). The pathogenesis of PAH within the context of CTDs involves a complex interplay of immune-mediated vascular damage, chronic inflammation, and fibrosis (4). Common symptoms of CTD-PAH include dyspnea, fatigue, chest pain, and syncope, necessitating a multidisciplinary approach to management (5). Current therapeutic strategies for CTD-PAH encompass both immunosuppressive therapies and PAH-specific treatments. Immunosuppressive therapy, including corticosteroids and disease-modifying antirheumatic drugs (DMARDs), aims to control inflammation and manage the underlying CTD (6). PAH-specific therapies, such as endothelin receptor antagonists (ERAs), phosphodiesterase type 5 inhibitors (PDE5i), and prostacyclin analogs, target pulmonary artery pressure and ameliorate symptoms associated with PAH (7).

In the quest for innovative treatment modalities, molecular hydrogen (H₂) therapy has emerged as a promising approach due to its unique biological properties. Molecular hydrogen exerts its effects through various mechanisms, including antioxidant, anti-inflammatory, anti-apoptotic, and gene expression modulation (8). Importantly, H₂ is naturally occurring and non-toxic at therapeutic concentrations, making it suitable for long-term use (9). Research into H₂ therapy spans across diverse medical conditions, including stroke, myocardial ischemia-reperfusion injury, chronic kidney disease, diabetes, and chronic obstructive pulmonary disease (COPD) (10-13). A crucial mechanism through which H₂ exerts its therapeutic effects is by the activation of the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2). Nrf2 is known for enhancing the transcription of a broad range of anti-stress enzymes, including antioxidant enzymes. The activation of Nrf2 by H₂ involves a complex interaction with hydroxyl radicals (•OH) and heme (PrP-Fe(II)). Initially, the hydroxyl radical oxidizes heme, forming PrP-Fe(III)-OH, which subsequently reacts with H₂ to produce PrP-Fe(III)-H and water. The PrP-Fe(III)-H complex acts as an electrophile that oxidizes Kelch-like ECH-associated protein 1 (Keap1), triggering the release and activation of Nrf2. This pathway enables H₂ to indirectly mitigate oxidative stress by activating Nrf2 and its downstream antioxidant responses (14).

The hydrogen capsule is formulated by immobilizing hydrogen on the surface of coral calcium, primarily derived from coral exoskeletons. This method ensures stable delivery of hydrogen and demonstrates antioxidative properties (13,15). A study evaluated the safety and lipid-lowering effects of hydrogen capsule in patients with metabolic syndrome, suggesting potential benefits in reducing lipid levels (13). In an experiment using a methionine-and-choline-deficient (MCD) diet-induced non-alcoholic fatty liver disease (NAFLD) mouse model, hydrogen capsules were found to alleviate lipid accumulation and liver dysfunction. The study further highlighted the antioxidative and anti-inflammatory effects of hydrogen capsule (15). The hydrogen capsule has demonstrated efficacy in decreasing ethanol-induced hepatic inflammation and alleviating alcohol hangover symptoms in mice, which includes reduced levels of pro-inflammatory cytokines, such as TNF-α, IL-6, and CCL2 (16). Another study observed a significant increase in resting regulatory T cell levels following hydrogen capsule treatment, along with a notable decrease in Fas+ helper T cells and cytotoxic T cell subtypes in a patient with PF-ILD complicated by pneumonia (17). These findings underscore the diverse therapeutic potential of hydrogen capsules, encompassing antioxidative, anti-inflammatory, and lipid-lowering properties, particularly in the contexts of liver health, lung disease and metabolic syndrome.

This article presents a case study of a 56-year-old female diagnosed with CTD-PAH awaiting lung transplantation. Despite receiving standard treatments, the condition remained unresponsive, prompting the initiation of hydrogen therapy as an adjuvant treatment (18,19). This study was approved by the Institutional Review Board (IRB) of Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, and complied with relevant guidelines (IRB: B202105106, approval date: 18 July 2023). Written informed consent was obtained from all patients (No. B202105106-24). The study adhered to the ethical standards of the institution and the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.

Case Report

A 56-year-old female patient presented with complaints of dyspnea that required oxygen supplementation. Her medical history dates back to July 2013 when she was hospitalized in the chest ward for dyspnea and cough with yellow sputum. She was subsequently diagnosed with Sjogren’s syndrome (20) complicated with interstitial lung disease (ILD) (21) and PAH (22) (Table I). Her chest X-ray at that time showed vascular markings with interstitial thickening, costophrenic (CP) angle blunting and cardiomegaly (Figure 1A). An echocardiogram revealed a pulmonary arterial (PA) systolic pressure of 99 mmHg, enlargement of the right atrium and ventricle, D-shaped left ventricle (LV), and severe tricuspid regurgitation. Chest CNYCT showed no filling defects, excluding pulmonary embolism; it also displayed an enlarged pulmonary trunk, right atrium (RA), and right ventricle (RV), further evidencing pulmonary hypertension (Figure 1E and F). Symptoms of dry mouth, dry eyes, and cracked tongue mucosa, with a Schirmer’s test showing <5 cm, oculus uterque (OU). A positive minor salivary gland biopsy, nuclear medicine scan showing impaired salivary gland function, and a positive anti-Ro test, confirmed Sjogren’s syndrome (Table I) (20). She started on Revatio (Sildenafil) (Figure 2) 20 mg three times a day (TID) for pulmonary hypertension control, adding Tracleer (Bosentan) (Figure 2) in 2016 due to disease progression (7). A right heart catheterization (RHC) revealed a mean pulmonary arterial pressure (PAP) of 39 mmHg, pulmonary vascular resistance (PVR) nearly 15 Woods, and a wedge pressure of 4, indicating pre-capillary type, group I, CTD-related PAH in 2017 (23). The right heart catheterization (RHC) report allowed for insurance coverage of Opsumit (Macitentan) (Figure 2) 10 mg once a day (QD), replacing Tracleer (Bosentan) in 2017. From 2017 to 2020, she was hospitalized multiple times for steroid treatments to manage her underlying Sjogren’s syndrome (6).

Table I. The illness of the patient on August 22, 2013 encompassed interstitial lung disease (ILD), Sjogren’s syndrome, and pulmonary arterial hypertension (PAH) complicated with heart failure (HF).

CXR: Chest X-ray; HRCT: high-resolution computed tomography; OU: oculus uterque; Anti-SSA(Ro): anti–Sjögren’s-syndrome-related antigen A autoantibodies; CT: computed tomography; RA: right atrium; RV: right ventricle; Echo: echocardiogram; TR3+: tricuspid valve regurgitation grade 3; mPAP: mean pulmonary arterial pressure; PCWP: pulmonary capillary wedge pressure; PVR: pulmonary vascular resistance.

Figure 1.

Clinical course of the patient. (A) CXR image on August 7, 2013, showing increased pulmonary vasculatures with interstitial lines thickening over bilateral lung fields. (B) CXR image on April 12, 2024, showing hazy opacities and bronchiectasis in bilateral lungs and reticulations in bilateral basal lungs. (C and D) High-resolution computed tomography (HRCT) images taken on August 2013 showing hazy ground-glass attenuation and thickening of interstitial lines. Chest computed tomography (CT) with contrast on August 2013 showing dilated pulmonary trunk with 4.04 cm, RA and RV.

Figure 2.

The timeline of pulmonary hypertension therapy. The orange squares indicate the time of evaluation for lung transplantation and cardiogenic shock s/p ECMO and intubation. The blue square indicates the stable disease after adding molecular hydrogen as adjuvant therapy. Green color highlights the time molecular hydrogen was added.

Pulmonary hypertension treatment is risk-based (24), and until 2017 (Figure 2), the patient was considered low to intermediate risk, controlled with two medications (Sildenafil + Macitentan). Her condition remained stable until October 2020, when she experienced worsened dyspnea accompanied by cough and expectoration of white sputum, suggestive of infection. On November 10, 2020, the patient experienced severe dyspnea, cold sweats, and cyanosis, with SpO₂ dropping to 70%, necessitating 100% O₂ via face tent. Blood gas and lab tests revealed a lactate level of 5.2 mmol/l and brain natriuretic peptide (BNP) over 10,000 pg/ml, strongly suggesting cardiogenic shock. She was prepped for intensive care unit (ICU) admission, intubated, and initiated on four pulmonary hypertension medications (Figure 2). Her condition stabilized and showed improvement, preventing further deterioration. On November 12, 2020, evaluation for heart-lung transplantation began. Her condition continued to improve with off vasopressors on November 13, 2020, and extubating on November 14, 2020, and transferred to a general ward on November 21, 2020, with O₂ tapered to nasal cannula 2l/min. A follow-up RHC continued to show elevated pulmonary artery pressure, likely attributed to chronic hypertension leading to right heart strain and eventual failure. After intensive care unit (ICU) treatment, she was referred to National Taiwan University Hospital for evaluation for heart-lung transplant.

Reviewing the records since the onset of her illness, it was evident that pulmonary artery pressure had steadily increased, and the distance covered in the 6-minute walk test was progressively shortened. Currently, the patient is classified as high risk. She continues regular hospitalizations for control. Despite the relatively stable condition, her chief complaint during the admission is still dyspnea. The physical examination revealed mild rhonchi ILD and a pansystolic murmur indicative of severe valvular heart disease, with no other significant findings. Ventavis (Iloprost) (Figure 2) 10 mcg/ml 2 ml was added in 2020. Molecular hydrogen therapy (1 capsule/day) was initiated in May 2023 (Figure 2). Hydrogen capsules (PURE HYDROGEN) were purchased from HoHo Biotech Co., Ltd. (Taipei, Taiwan, ROC). Each capsule contained 170 mg of hydrogen-rich coral calcium containing 1.7×1,021 molecules of hydrogen, which is equivalent to 24 cups of water with 1,200 ppb of hydrogen or 0.6 mM of hydrogen per 200 ml of water. Adjuvant therapy with hydrogen capsules resulted in increased CD127 + Treg, decreased anti-Ro antibody, decreased B cell subsets (Figure 3 and Figure 4), and stabilization of clinical symptoms and signs was observed following the addition of hydrogen therapy in this patient. No adverse reactions or events were observed following the administration of hydrogen capsules. Flow cytometry and serological examination were employed for whole-blood analysis to assess changes in immune cells and autoantibody before and after hydrogen therapy. For subsequent whole-blood analysis via flow cytometry, blood samples were prepared using standard fluorescent dye preparation methods and fluorescent antibody reagent kits with dried reagents (Beckman Coulter, Brea, CA, USA). The methods, steps, immunophenotypic analysis, and cell gating were conducted following previously described procedures (17,25,26). Our analysis of immunophenotypic markers before and after hydrogen therapy revealed increased CD127 + Treg and decreased B cell subsets after treatment (Figure 3). Moreover, this study adheres to the CARE reporting guidelines (2013 CARE Checklist).

Figure 3.

Immunophenotypic changes before and after molecular hydrogen therapy. Whole-blood analysis was conducted nineteen times: prior to molecular hydrogen therapy (up to February 18, 2023) and post-therapy (from May 18, 2023 till March 25, 2024). (A) Percentage change in CD127+Treg that shows increasing trend after molecular hydrogen therapy. (B) Percentage change in Tr1 cell that shows increasing trend after molecular hydrogen therapy. (C) Percentage change in B cells CD21+ that shows decreasing trend after molecular hydrogen therapy. (D) Percentage change in plasma cell CD19+ IgM+ that shows decreasing trend after molecular hydrogen therapy. (E) Percentage change in switch memory B cells CD21+ that shows decreasing trend after molecular hydrogen therapy. (F) Percentage change in B cells HLADR+ that shows decreasing trend after molecular hydrogen therapy. (G) Percentage change in Plasma cell that shows decreasing trend after molecular hydrogen therapy. (H) Percentage change in plasmablasts CD19+IgM+ that shows decreasing trend after molecular hydrogen therapy. SM: Switch memory.

Figure 4.

Immunophenotypic changes of anti-Ro antibodies before and after molecular hydrogen therapy. Whole-blood analysis was conducted twenty times: prior to molecular hydrogen therapy (up to March 6, 2023) and post-therapy (from May 18, 2023 till May 20, 2024). Anti-Ro antibodies show decreasing trend after molecular hydrogen therapy.

Discussion

This case study underscores the urgent need for novel interventions to treat cases of CTD-PAH. Despite approximately ten years of increasing pharmacological and non-pharmacological interventions, such as sildenafil, selexipag, macitentan, and iloprost, symptoms persisted without relief, ultimately requiring emergency measures due to cardiogenic shock (Figure 2). The observed increase in CD127+ regulatory T cells (Treg) following molecular hydrogen therapy suggests a potential immunomodulatory effect. CD127+ Treg cells play a crucial role in immune regulation and tolerance, and their expansion may contribute to dampening excessive immune responses implicated in CTD-PAH pathogenesis (27). This finding is consistent with prior research highlighting the anti-inflammatory properties of molecular hydrogen (8). The decrease in anti-Ro antibodies subsequent to molecular hydrogen therapy suggests a possible attenuation of autoimmune processes associated with CTD-PAH. Anti-Ro antibodies are frequently detected in autoimmune disorders like Sjogren’s syndrome (20) and have been associated with pulmonary vascular complications (28). The capacity of molecular hydrogen to modulate autoimmunity and reduce antibody production underscores its potential as a novel therapeutic approach in managing CTD-PAH. The reduction in B cell subsets indicates a modulation of B cell function through molecular hydrogen therapy. Dysregulated B cell responses have been implicated in the pathogenesis of autoimmune diseases and pulmonary hypertension (29). By targeting B cell subsets, molecular hydrogen may help mitigate aberrant immune activation and prevent further vascular damage in patients with CTD-PAH (30). Overall, the findings from this case study support the potential therapeutic benefits of molecular hydrogen in managing CTD-PAH. Through its anti-inflammatory and immunomodulatory effects, molecular hydrogen has shown promise in mitigating disease progression and enhancing clinical outcomes in patients resistant to conventional treatments. Moreover, the favorable safety profile of molecular hydrogen, as evidenced by the absence of adverse reactions in this study, highlights its potential as a well-tolerated adjunctive therapy for patients with CTD-PAH awaiting lung transplantation.

In conclusion, this case study highlights the effectiveness of hydrogen-assisted therapy for patients with CTD-PAH awaiting lung transplantation. Further research is necessary to elucidate the mechanisms underlying molecular hydrogen therapy and refine treatment protocols for optimal efficacy. Long-term prospective studies are warranted to assess the durability of treatment effects and evaluate its impact on disease prognosis and survival outcomes in CTD-PAH patients. Furthermore, randomized controlled trials comparing molecular hydrogen therapy with standard treatments are essential to validate its therapeutic potential and guide clinical practice guidelines for managing CTD-PAH. Although hydrogen-assisted therapy shows promise as a treatment option, future studies with larger sample sizes and long-term follow-up are needed to substantiate its efficacy and establish correlations between hydrogen therapy and CD127+ Treg cells, anti-Ro antibodies, and B cell subsets.

Conclusion

The therapeutic potential of molecular hydrogen is promising due to its multifaceted mechanisms of action, which include potent antioxidant, anti-inflammatory, and anti-apoptotic effects (8). The complex interaction involving the activation of Nrf2 by H₂ suggests that H₂ may mitigate oxidative stress indirectly by enhancing Nrf2 activity and its downstream antioxidant responses. Further investigation of Nrf2 in clinical settings may be warranted. The broad applications of molecular hydrogen across various diseases underscore its versatility and safety, warranting additional research into its potential as a novel treatment modality. This is particularly relevant in conditions like CTD-PAH, where oxidative stress and inflammation play crucial roles.

Conflicts of Interest

The Authors declare no conflicts of interest or competing interests in relation to this study.

Authors’ Contributions

YTL: Conceptualization, methodology, writing – original draft, writing review and editing. JWL: Conceptualization, methodology, writing original draft, writing review and editing. YJH: Conceptualization, methodology, project administration, writing original draft, writing review and editing. SWL: Conceptualization, methodology, writing original draft, writing review and editing. TYH: Conceptualization, methodology, writing original draft, writing review and editing. FCL: Conceptualization, investigation, supervision, writing review and editing.

Acknowledgements

This study was supported by the Undergraduate Research Fellowship, Ministry of Science and Technology (MOST 111-2314-B-016-026), the National Science and Technology Council (NSTC 112-2314-B-016-033; NSTC 113-2314-B-016-052), Tri-Service General Hospital (TSGH-E-111215; TSGH-E-112218) in Taiwan.