However, response to treatment varies depending on the causative genetic abnormality. initial treatment with haemodialysis, plasma exchange, and standard immunosuppressive therapy (steroid and cyclophosphamide) did not appreciably improve kidney function JAK1-IN-4 and thrombocytopaenia, the patient was able to respond to eculizumab therapy. Conclusions Due to the related features of TMA and SLE, medical suspicion of aHUS in individuals with lupus nephritis is definitely important for early analysis and prompt management. Timely administration of eculizumab should be considered as a treatment option for aHUS in lupus MAP2K2 nephritis individuals to yield ideal therapeutic results. O157:H7. Due to the medical manifestations and laboratory findings, diagnoses of TMA and SLE were made. The time sequence of important events and the clinical course are offered in Fig.?1. Plasmapheresis was JAK1-IN-4 started to treat SLE and TMA. Haemodialysis was initiated due to oliguria and volume overload. The patients received pulse IV methylprednisolone and 500?mg cyclophosphamide every 2 weeks. Although thrombocytopaenia improved, the platelet count (103,000/L) and kidney function parameters (blood urea nitrogen 59.7?mg/dL, serum creatinine 4.95?mg/dL) were not within normal limits. Open in a separate windows Fig. 1 Clinical course and key events.?Abbreviations: E, eculizumab; IV, intravenous; PLT, platelet; UACR, urine albumin-to-creatinine ratio Around the 15th hospital day, ultrasound-guided percutaneous kidney biopsy was performed. JAK1-IN-4 Light microscopy of renal biopsy specimens has shown diffuse proliferative lupus nephritis, class IV-G (active) with mesangiolysis and arteriolar fibrin thrombi indicative of TMA (Fig.?2). Immunofluorescence staining has shown a full-house pattern (positive for IgG, IgA, IgM, C3, and C1q) in the mesangium and peripheral capillary wall. Based on these renal biopsy findings, a diagnosis of lupus nephritis with TMA was confirmed. Open in a separate windows Fig. 2 Pathological findings of kidney biopsy.?a Light microscopy, Haematoxylin and eosin staining (H&E). Lobular accentuation with panhypercellularity and multiple layers of capillary wall with focal segmental mesangiolysis (arrow). b Light microscopy, H&E. Glomerulus showing marked thickened capillary loop (wire loop lesion). c Light microscopy, silver staining. Cellular crescent in glomerulus. d Light microscopy, silver staining. Afferent arterioles affected by fibrinoid necrosis Next-generation sequencing and whole exon sequencing have revealed heterozygous mutation c.1685?C? ?T (p.ser562Leu) of the C3 gene. The presence of C3 mutation and incomplete response to standard immunosuppression (Fig.?1) are consistent with diagnosis of co-existent lupus nephritis and aHUS (complement-mediated TMA). Haemodialysis and cyclophosphamide therapy was discontinued after 10 sessions and 3 administrations, respectively. Around the 51st hospital day, treatment was shifted to intravenous eculizumab at an initial dose of 900?mg for four occasions a week escalated to 1 1,200?mg every two weeks thereafter. After 32 cycles, there was complete resolution of haemolytic anaemia (haemoglobin 13.7?g/dL, haematocrit 41.8?%, and haptoglobin 119?mg/dL), thrombocytopaenia (platelet count 149,000/L), and azotaemia (blood urea nitrogen 13.0?mg/dL, serum creatinine 1.10?mg/dL). The lactate dehydrogenase level normalized (154 U/L) and the Urine albumin-to-creatinine ratio (206.4?mg/g) was greatly improved (Table?1). At the time of writing this statement, the patient was taking a 10-mg dose of a corticosteroid daily together with eculizumab therapy. Conversation and conclusions Kidney involvement is usually common in SLE presenting with numerous pathologic patterns and clinical features. TMA, a rare but life-threatening complication of SLE, is usually characterised by endothelial injury that may cause thrombosis to the arterioles and capillaries. This results to microangiopathic haemolytic anaemia, thrombocytopaenia, and end-organ damage such as kidney impairment . A retrospective study has shown that TMA development after SLE is usually more common than simultaneous occurrence of lupus nephritis and TMA . The presence of TMA with SLE experienced poor renal outcomes despite standard immunosuppressive drugs and plasmapheresis. The median overall survival in patients treated with vigorous immunosuppressive therapy and plasmapheresis was 2.9 months and 103.5 months in the concurrent (TMA-SLE) group and sequential (TMA development after SLE) group, respectively . The individual was initially diagnosed with both TMA and SLE and; hence, it is usually a case of concurrent TMA-SLE. Despite recent improvements regarding the mechanisms of TMA, a diagnosis.