A Very Rare Case of Secondary Hemophagocytic Lymphohistiocytosis in an AIDS Patient With Refractory Septic Shock and Overwhelming Disseminated Histoplasmosis

Abstract

INTRODUCTION: We report a very rare case of secondary hemophagocytic lymphohistiocytosis (HLH) in a patient with newly diagnosed AIDS and disseminated histoplasmosis presented with refractory septic shock and MOD. To our knowledge, we could find no report of secondary HLH and disseminated histoplasmosis associated with Septic shock in an AIDS patient. CASE PRESENTATION: 59-year-old male presents with two weeks of fever, dyspnea, productive cough, and maculonodular skin rash associated with weight loss, nausea, and vomiting. He was recently diagnosed with HIV and treated empirically for Pneumocystis jiroveci pneumonia without response to treatment. Initial chest X-ray revealed diffuse interstitial infiltrates and micronodular opacities. CT Chest showed diffuse noncalcified pulmonary nodules with diffuse ground-glass opacities. Skin biopsy showed dermal histoplasmosis. Fungal blood cultures positive for Histoplasma capsulatum. His ICU course was complicated with refractory septic shock, anuric acute kidney injury requiring RRT, and bone marrow failure. This patient fulfilled diagnostic criteria for hematophagocytic lymphohistiocytosis (HLH) as well as histological criteria with bone marrow biopsy. He expired after one month in ICU despite aggressive treatment. DISCUSSION: HLH is a rare syndrome that is often fatal despite treatment. It is caused by a dysregulation in natural killer T-cell function, resulting in activation and proliferation of histiocytes with uncontrolled hemophagocytosis and cytokine overproduction. Diagnosis of HLH requires five of the following criteria: fever, hepatosplenomegaly, hemophagocytosis, cytopenia in at least two lines, a markedly elevated ferritin, high triglycerides and/or low fibrinogen, high-soluble IL-2R/CD25 and little or no natural killer cell activity, that are common features of severe sepsis/septic shock. Early diagnosis of HLH can be challenging in the critically Ill patient with nonspecific symptomatology, especially in AIDS patients. Generally, management has been directed toward a combination of treating the underlying cause and some combination of immunosuppressive therapy. CONCLUSIONS: Consideration of HLH in a patient with septic shock with MOD, especially in the AIDS patient with multiple opportunistic infections, may lead to improved mortality if detected early. Further study of HLH in the critical care setting might provide important insights into clinical treatment of sepsis.