Phase II study of continuous infusion recombinant gamma interferon in renal carcinoma. A Southwest Oncology Group study

Hemophagocytosis causes a consumptive anemia of inflammation

Cytopenias of uncertain etiology are commonly observed in patients during severe inflammation. Hemophagocytosis, the histological appearance of blood-eating macrophages, is seen in the disorder hemophagocytic lymphohistiocytosis and other inflammatory contexts. Although it is hypothesized that these phenomena are linked, the mechanisms facilitating acute inflammation-associated cytopenias are unknown. We report that interferon γ (IFN-γ) is a critical driver of the acute anemia observed during diverse microbial infections in mice. Furthermore, systemic exposure to physiologically relevant levels of IFN-γ is sufficient to cause acute cytopenias and hemophagocytosis. Demonstrating the significance of hemophagocytosis, we found that IFN-γ acts directly on macrophages in vivo to alter endocytosis and provoke blood cell uptake, leading to severe anemia. These findings define a unique pathological process of broad clinical and immunological significance, which we term the consumptive anemia of inflammation.

Single institution experience with recombinant gamma-interferon in the treatment of patients with metastatic renal cell carcinoma

We report the clinical course of eight patients with metastatic renal cell carcinoma (RCC) who were treated with recombinant gamma-interferon (Immuneron) as part of a phase II-III study comparing the safety and efficacy of gamma-interferon with that of medroxyprogesterone acetate (Depo-Provera). There were no objective responders among the eight patients treated with recombinant gamma-interferon at an i.v. dose of 1 mg/m(2) daily for five days every other week for four weeks then 1 mg/m(2) three times a week given every other week until there was documented disease progression or complete response (CR). Overall median survival was 17.3 months (range 1.4 to 184). The major side effects of treatment included fever/chills (75%), mild anorexia and fatigue (75%), nausea/vomiting (80%), leukopenia (38%), and abnormal liver function tests (25%). There were no life-threatening side effects observed. At our institution, in a random cohort of eight patients with metastatic RCC, recombinant gamma-interferon when given at a dose of 1 mg/m(2) per day given three times per week on an every other week schedule yields no clinical antitumor activity. A review of the literature on the use of gamma-interferon for metastatic RCC suggests that low-dose combination therapy with other cytokines may yield the best response-to-side effect ratio. Higher doses yield more responses but an added cost of more toxicity.

Rationale for immunotherapy of renal cell carcinoma

Metastasis to distant organs is the principal cause of death from renal cell carcinoma (RCC). No commonly accepted therapy is available for disseminated RCC at present. Immunotherapy is a mode of therapy that either interferes with the immune system or makes use of drugs that have been derived from soluble mediators of the immune system. Several lines of evidence suggest that combinations of genetically engineered cytokines (e.g. interleukin-2 and interferon alpha) may be particularly active in the treatment of advanced RCC. There are two major rationales for considering immunotherapy for RCC: (1) there is currently no other therapy available, and (2) there is hardly any innovative approach besides immunotherapy. Still, immunotherapy is far from being a standard therapy for disseminated RCC.