Serious renal involvement in systemic diseases is common and generally constitutes a pivotal prognostic factor, making those pathology frequently seen in nephrology departments. Authors describe the case of a nine-year-old girl with lupus nephritis. After admission the patient’s state deteriorated over a period of a few days, with an unremitting high-grade fever, significant weakness and drowsiness, generalized erythema, and decrease of the kidney function to eGFR nadir of 56 ml/min/1,73m ². Treatment with pulsed methylprednisolone was started. After the first pulse the general state of the patient improved slightly, although laboratory tests showed an alarming evolution, with the exacerbation of anemia, leukopenia, neutropenia, increase of serum CRP concentration, extremely high D-dimer concentration and increase in activity of lactate dehydrogenase. The concentration of ferritin rose reaching the level of 540 μg/l, triglicerydes level was also high. Intravenous cyclophosphamide pulse therapy was added to the ongoing steroid treatment, and resulted in a radical patient improvement. Authors underline that it seems important to be aware of rare, non-renal, but potentially devastating complications of systemic diseases, like in this clinical case: the secondary hemophagocytic lymphohistiocytosis (HLH). When HLH complicates a rheumatic disease, it is also referred to as macrophage activation syndrome (MAS). Unfortunately treatment of MAS is still based on reports provided by individual centres and gathered own experiences so drawing up unambiguous diagnostic criteria will be valuable in future. The treatment should be individually tailored, and more specific evidence-based recommendations are needed.

严重的肾脏累及全身性疾病是很常见的，通常构成关键的预后因素，这使得这些病理在肾脏科经常见到。作者描述了一个9岁的狼疮性肾炎女孩的病例。入院后患者的病情在几天内恶化，伴有持续的高烧，明显的虚弱和嗜睡，全身性红斑以及肾功能下降至eGFR最低点56 ml / min / 1,73m ²。开始用脉冲甲基强的松龙治疗。在第一个脉冲后，尽管实验室检查显示出令人震惊的进展，但随着贫血，白血球减少，中性粒细胞减少，血清CRP浓度增加，D-二聚体浓度极高以及乳酸脱氢酶活性增加，患者的总体状况有所改善。 。铁蛋白的浓度上升到540μg/ l的水平，小麦粉的水平也很高。正在进行的类固醇治疗中加入了静脉注射环磷酰胺脉冲疗法，从而使患者得到了根本的改善。作者强调，了解罕见，非肾脏但具有破坏性的全身性疾病似乎很重要，例如在本临床病例中：继发性吞噬性淋巴细胞组织细胞增生症（HLH）。当HLH使风湿病并发时，它也被称为巨噬细胞活化综合症（MAS）。不幸的是，MAS的治疗仍基于各个中心提供的报告并收集了自己的经验，因此制定明确的诊断标准在将来将很有用。治疗应个体化，并且需要更具体的循证推荐。