RAS-associated autoimmune lymphoproliferative disorder: A case report and literature review

Objective To investigate the clinical features and diagnosis and treatment of RAS-associated autoimmune lymphoproliferative disorder (RALD). Methods We reported the clinical data of a case of RALD diagnosed and treated in our hospital in 2019, and reviewed relevant literature on RAS variation retrieved using the keywords “NRAS”, “KRAS”, and “RALD” through PubMed, CNKI, and Wanfang Data between January 2000 and November 2023. Results The patient was hospitalized due to recurrent fevers for 1.5 months with a 1.5 years history of thrombocytopenia. The physical signs included an appearance of mild anemia, an abdominal bulge, a hard liver palpable up to 5 cm below the costal margin, and the spleen edge up to 3 cm below the costal margin. CD4-CD8- cells accounted for 2.3% of lymphocytes. The degranulation of NK cells decreased. Gene sequencing detected a somatic mutation in exon 2 of the NRAS gene c.38G>A(p.G13D). A total of 32 cases of RALD were retrieved, including 13 cases caused by NRAS somatic mutations and 19 cases caused by KRAS somatic mutations. The main clinical features of the 32 patients included splenomegaly, autoimmune anemia, thrombocytopenia, hypergammaglobulinemia, mononuc-leosis, a normal or slightly elevated proportion of double-negative T cells. Conclusion RALD is characterized by hepatosplenomegaly and autoimmunity, and gene testing is helpful for its diagnosis.