A Case of Recurrent Pregnancy-Induced Adult Onset Familial Hemophagocytic Lymphohistiocytosis

A Case Report of Pregnancy Complicated with Primary Hemophagocytic Lymphohistiocytosis

Background

Hemophagocytic lymphohistiocytosis (HLH) is a severe hyperinflammatory syndrome characterized by excessive activation of NK cells and cytotoxic T lymphocytes, subsequently leading to macrophage activation and increased cytokine production. Misdiagnosis due to nonspecific clinical presentations and inadequate understanding of the disease can significantly jeopardize the safety of both the mother and the infant. We report a case of pregnancy combined with HLH and conduct a literature review to provide insights into the diagnosis and treatment of pregnancy-related HLH.

Case Presentation

We discussed a case of a pregnant woman with persistent postpartum fever, serum ferritin, and elevated liver function, who failed to respond to repeated anti-infective therapy and was diagnosed with HLH after multidisciplinary diagnostic treatment. We gave dexamethasone treatment, and the patient's temperature and blood cells quickly returned to normal. Finally, exome sequencing revealed heterozygous variation in UNC13D gene, so we considered this case as pregnancy combined with primary HLH (pHLH).

Conclusion

We report the case of HLH diagnosed during pregnancy and show that early diagnosis and timely intervention can prevent rapid disease progression, reduce maternal mortality rates, and improve survival rates. Additionally, molecular genetic testing can confirm pathogenic gene mutations, providing essential genetic counseling for patients with pHLH who plan to conceive a healthy child.

UNC13D inhibits STING signaling by attenuating its oligomerization on the endoplasmic reticulum

Stimulator of interferon genes (STING) is an essential signaling protein that is located on the endoplasmic reticulum (ER) and triggers the production of type I interferons (IFN) and proinflammatory cytokines in response to pathogenic DNA. Aberrant activation of STING is linked to autoimmune diseases. The mechanisms underlying homeostatic regulation of STING are unclear. Here, we report that UNC13D, which is associated with familial hemophagocytic lymphohistiocytosis (FHL3), is a negative regulator of the STING-mediated innate immune response. UNC13D colocalizes with STING on the ER and inhibits STING oligomerization. Cellular knockdown and knockout of UNC13D promote the production of interferon-β (IFN-β) induced by DNA viruses, but not RNA viruses. Moreover, UNC13D deficiency also increases the basal level of proinflammatory cytokines. These effects are diminished by an inhibitor of STING signaling. Furthermore, the domains involved in the UNC13D/STING interaction on both proteins are mapped. Our findings provide insight into the regulatory mechanism of STING, the previously unknown cellular function of UNC13D and the potential pathogenesis of FHL3.

Case report and literature review: Hemophagocytic lymphohistiocytosis in a pregnant woman with systemic lupus erythematosus with Syntaxin 11 gene defect

Hemophagocytic lymphohistiocytosis is an extremely rare occurrence during pregnancy. Early recognition of its signs and symptoms is critical for early intervention, and delays in diagnosis may be life-threatening. A 23-year-old nulliparous woman presented with a persistent fever as high as 39°C with bilateral edema of the lower limbs at 24 weeks of gestation. Typical laboratory findings included pancytopenia, high triglycerides, ferritin, transaminases, bilirubin, and hypoproteinemia. Active systemic lupus erythematosus was diagnosed using an autoimmune work-up and a Systemic Lupus Erythematosus Disease Activity Index 2000 score of 17 points. Her bone marrow aspirate revealed prominent hemophagocytosis; hence, HLH was confirmed. Genetic tests showed mutations in Syntaxin 11 mutations. Considering the potential impact of drugs on the fetus, the patient and her family members chose to terminate the pregnancy through medical induction of labor. Afterwards, her condition improved with immunosuppressive therapy.

Hemophagocytic lymphohistiocytosis during pregnancy: a review of the literature in epidemiology, pathogenesis, diagnosis and treatment

Hemophagocytic lymphohistiocytosis during pregnancy is rare; it is often misdiagnosed, resulting in a high maternal and foetal mortality rate. Herein, based on limited case reports including antepartum and postpartum cases, we reviewed the current studies of pregnancy-related hemophagocytic lymphohistiocytosis, and compared the epidemiology, aetiology, diagnosis and treatment of pregnancy-related hemophagocytic lymphohistiocytosis with non-pregnancy, enriching the understanding of hemophagocytic lymphohistiocytosis and its treatment in obstetrics.

A Fatal Case of Dengue-Associated Hemophagocytic Lymphohistiocytosis and Retroperitoneal Hematoma in a Patient With Autoimmune Hemolytic Anemia

Hemophagocytic lymphohistiocytosis (HLH) is a rare but potentially life-threatening complication of dengue infection which necessitates early diagnosis and treatment to improve patient outcomes. Severe dengue infection complicated by HLH may require interventions such as systemic corticosteroids, intravenous immunoglobulin, or chemotherapy. Here, we report a case of concurrent dengue-induced HLH and flare of underlying autoimmune hemolytic anemia (AIHA). The disease was refractory to treatment including corticosteroids and intravenous immunoglobulin. The course of illness was later complicated by dengue shock syndrome, severe liver dysfunction, and a large retroperitoneal hematoma. Unfortunately, the patient succumbed on day 10 of illness.

Requirement for etoposide in the treatment of pregnancy related hemophagocytic lymphohistiocytosis: a multicenter retrospective study

Background

Hemophagocytic lymphohistiocytosis (HLH) is a rare severe clinical syndrome. HLH manifesting during pregnancy has been paid much attention in recent years. Despite the specificity of pregnancy-related HLH, there has not been any consensus regarding its treatment. According to a previous study, corticosteroid/IVIG is the mainstream therapy; however, the efficacy is controversial. Etoposide is an important agent in the HLH-94 regimen; nevertheless, its use is limited because of possible toxicity to the fetus. Methods: In this study, we summarized 13 cases from 4 medical institutions from April 2011 to April 2018. Treatment regimens and outcomes were observed.

Results

The median age was 26 (20–36) years old. The median gestational age was 28 (10–35) weeks. In these 13 patients, 10 were treated with methylprednisolone/IVIG and was effective in only two patients. In 6 patients who used etoposide during their treatment, all achieved remission. The median time from onset of disease to use of etoposide was 36 (17–131) days. Five of these 6 patients were treated with corticosteroids with/without IVIG before etoposide. One patient with pulmonary tuberculosis and one with lymphoma were treated according to etiology and achieved long survival.

Conclusion

For treatment of pregnancy-related HLH, particularly for patients who do not respond to corticosteroids/IVIG therapy, etoposide should be used bravely. Nevertheless, suitable dosages and toxic and side-effects require further clinical observation.