Clinical features of 47 secondary hemophagocytic lymphohistiocytosis patients complicated with capillary leak syndrome

Intravascular large B-cell lymphoma as a covert trigger for hemophagocytic lymphohistiocytosis complicated with capillary leak syndrome: a case report and literature review

Intravascular large B-cell lymphoma (IVLBCL) is a rare subtype of non-Hodgkin lymphoma. Patients with hemophagocytic lymphohistiocytosis (HLH)-associated IVLBCL variants exhibit significantly poor survival. Cytokines play pivotal roles in malignancy-associated HLH as well as in capillary leak syndrome (CLS). The pathogenesis of CLS involves hyperpermeability and transient endothelial dysfunction. Here, we report the first case of HLH-associated IVLBCL variant complicated with CLS. The patient presented with fever, refractory hypoproteinemia, hypotension and severe edema, followed by telangiectasias. Treatment with etoposide and dexamethasone and hydroxyethyl starch-based artificial colloid led to transient improvement. The diagnosis of IVLBCL was confirmed after the sixth bone marrow biopsy. Subsequently, the R-CHOP (rituximab, cyclophosphamide, hydroxydaunorubicin, vincristine, and prednisolone) regimen was administered and resulted in prompt alleviation of CLS and HLH symptoms. The patient has survived for more than 6 years after combination of immunochemotherapy and autologous peripheral stem-cell transplantation. This case provides some insights into the mechanism and clinical management of IVLBCL complicated with HLH and CLS. Similar cases concerning lymphoma-associated CLSs were also reviewed.

A predictive model for identifying secondary underlying diseases of hemophagocytic lymphohistiocytosis

Background

Secondary hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening disease of immune hyperactivation that arises in the context of infectious, inflammatory, or neoplastic triggers. The aim of this study was to establish a predictive model for the timely differential diagnosis of the original disease resulting in HLH by validating clinical and laboratory findings to further improve the efficacy of therapeutics for HLH.

Methods

We retrospectively enrolled 175 secondary HLH patients in this study, including 92 patients with hematologic disease and 83 patients with rheumatic disease. The medical records of all identified patients were retrospectively reviewed and used to generate the predictive model. We also developed an early risk score using multivariate analysis weighted points proportional to the β regression coefficient values and calculated its sensitivity and specificity for the diagnosis of the original disease resulting in HLH.

Results

The multivariate logistic analysis revealed that lower levels of hemoglobin and platelets (PLT), lower levels of ferritin, splenomegaly and Epstein-Barr virus (EBV) positivity were associated with hematologic disease, but young age and female sex were associated with rheumatic disease. The risk factors for HLH secondary to rheumatic diseases were female sex [OR 4.434 (95% CI, 1.889-10.407), P =0.001], younger age [OR 6.773 (95% CI, 2.706-16.952), P<0.001], higher PLT level [OR 6.674 (95% CI, 2.838-15.694), P<0.001], higher ferritin level [OR 5.269 (95% CI, 1.995-13.920), P =0.001], and EBV negativity [OR 27.656 (95% CI, 4.499-169.996), P<0.001]. The risk score included assessments of female sex, age, PLT count, ferritin level and EBV negativity, which can be used to predict HLH secondary to rheumatic diseases with an AUC of 0.844 (95% CI, 0.836~0.932).

Conclusion

The established predictive model was designed to help clinicians diagnose the original disease resulting in secondary HLH during routine practice, which might be improve prognosis by enabling the timely treatment of the underlying disease.

HLH-Like Syndrome and Rhabdomyolysis in an Adolescent Patient

Hemophagocytic lymphohistiocytosis (HLH) is a rare heterogeneous group of disorders characterized by immune overactivation. It can occur because of primary genetic mutations or secondary to almost any inflammatory or infectious process. The clinical manifestations of this syndrome are varied and life-threatening and resemble those of many malignancies, infections, sepsis, and multisystem inflammatory syndrome in children. Laboratory abnormalities often are not diagnostic for HLH until late in the disease course, and the laboratory studies are send-out tests at most institutions. Thus, quickly and accurately diagnosing pediatric patients with HLH presents significant challenges to the clinician. Furthermore, there has been recent discussion in the literature regarding the use of diagnostic criteria for HLH. In this case report, we detail an adolescent male individual who developed persistent unexplained fever, rhabdomyolysis, and regional ischemic immune myopathy. To our knowledge, there is no previous report of a pediatric patient with this rare myopathy or HLH presenting with persistent rhabdomyolysis in the literature. The patient was hospitalized for a total of 61 days, with multiple treatments attempted throughout during his course of illness. In this report, we highlight the importance of using diagnostic flexibility when HLH is suspected in pediatric patients and provide insight into the unique challenges of identifying this condition.

Capillary leak syndrome: State of the art in 2021

Capillary leak syndrome (CLS) is an increasingly acknowledged multifaceted and potentially lethal disease. Initial nonspecific symptoms are followed by the intriguing CLS hallmark: the double paradox associating diffuse severe edema and hypovolemia, along with hemoconcentration and hypoalbuminemia. Spontaneous resolutive phase is often associated with poor outcome due to iatrogenic fluid overload during leak phase. CLS is mainly triggered by drugs (anti-tumoral therapies), malignancy, infections (mostly viruses) and inflammatory diseases. Its idiopathic form is named after its eponymous finder: Clarkson's disease. CLS pathophysiology involves a severe, transient and multifactorial endothelial disruption which mechanisms are still unclear. Empirical and based-on-experience treatment implies symptomatic care during the acute phase (with the eventual addition of drugs amplifying cAMP levels in the severest cases), and the prophylactic use of monthly polyvalent immunoglobulins to prevent relapses. As CLS literature is scattered, we aimed to collect and summarize the current knowledge on CLS to facilitate its diagnosis, understanding and management.