Scleroderma renal crisis: Case reports and update on critical issues.

To date, scleroderma renal crisis (SRC) remains a life-threatening complication in patients affected by systemic sclerosis (SSc), with high morbidity and mortality. In the last few years, some studies have tried to more precisely identify predictors of SRC and clarify the role of previous drug exposure-in particular, angiotensin-converting enzyme (ACE) inhibitors and corticosteroids-in patients with SSc presenting other well-known risk factors for SRC. Different from the findings of previous reports, more recent findings suggest that the presence of chronic kidney disease, systemic arterial hypertension, and proteinuria might all be predictors of SRC. Moreover, because about 40 to 50% of SRC cases can present signs of microangiopathy, a recent study has proposed SSc thrombotic microangiopathy (SSc-TMA) as a clinically and pathophysiologically different entity from narrowly defined SRC. Even though such clear distinction may not always be applicable/feasible in clinical practice, it highlights that complement pathway dysregulation may play a key pathogenetic role in SRC presenting as TMA. Thus, plasma exchange may be considered in severe refractory cases. Nevertheless, ACE inhibitors and prompt achievement of blood pressure control (to rapidly improve ongoing renal ischemia) remain to date the cornerstone of SRC treatment. Here, we report the cases of three SSc patients with SRC followed at our rheumatology units. While describing these patients' risk factors, clinical presentation, and therapy, we aim to discuss the state of the art in SRC and highlight critical issues.