Abstract Background/Aims Haemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening hyperinflammatory syndrome with a rapidly evolving evidence base. HLH can present in adults and may be triggered by infection, malignancy, or autoimmune disease. Increasingly, recognition of autoimmune-associated HLH has highlighted the need for rheumatological expertise in its diagnosis and management. Methods We describe the case of a 41-year-old Afro-Caribbean woman with a background of systemic lupus erythematosus (SLE) and lupus nephritis (positive antibodies to DsDNA, ANA and Smith), who presented acutely unwell at a clinic appointment. Her initial treatments prior to admission were hydroxychloroquine and mycophenolate, although she acknowledged she was not taking her medications. Initial investigations revealed thrombocytopaenia, pyrexia, and markedly elevated ferritin levels. She was transferred to the haematology ward, and urgent rheumatology input was sought. Anakinra and corticosteroids were commenced, promptly following a raised H-score of 188. Due to the patient having stopped all her medications, SLE was considered the likely trigger. After a period of initial improvement, she suddenly started to biochemically and clinically deteriorate. Results Immunosuppressive therapy was escalated to include restarting mycophenolate mofetil and hydroxychloroquine. Despite this, inflammatory markers worsened. A PET CT showed lymph node and splenic involvement indicating a possible lymphoma. This was subsequently discounted after haematological review with lymph node and two bone marrow biopsies performed. A comprehensive set of viral serologies were carried out, all of which were negative. The case was discussed at the national HLH multidisciplinary team meeting. During preparation for the MDT, a review of the patient’s records revealed two DNA appointments for follow-up of CIN 3 under gynaecology. An inpatient gynaecology referral was made with colposcope biopsies performed. Vulval histology showed multinucleation and intranuclear inclusions typical of herpes viral cytopathic. A referral to GUM was made and full screening showed HSV 2 detected by PCR. High dose acyclovir was initiated, and mycophenolate was stopped. A full sexually transmitted infection screen identified a mildly positive treponemal test for syphilis, which was treated empirically. The clinical significance of this finding remains uncertain. Remarkably, the patient demonstrated rapid clinical improvement within 48 hours of initiating antiviral therapy. She was discharged on acyclovir and continued anakinra and prednisolone, which were both subsequently tapered. Ferritin levels declined, and full recovery was presumed to have been achieved. Conclusion This case underscores the importance of early recognition and prompt treatment of HLH to mitigate morbidity and mortality. It highlights the diagnostic complexity in autoimmune-associated HLH and the necessity of thorough record review and multidisciplinary collaboration. Identifying and treating the underlying trigger(s) is paramount to achieving favourable outcomes. Disclosure R. Smith: None. D. Mynors-Wallis: None. A. Coy: None.
Smith et al. (Wed,) studied this question.