The Human Rights Committee of the Alumni Association of Iran's largest reformist student group says Lisani's health has deteriorated in prison.
The group also called for the conditional release of Abbasi, who has served seven months of a one-year prison term on charges of "acting against national security."
Lisani has been in jail since last June. He is reportedly on a hunger strike to protest against his conditions in prison.
Lisani 'Beaten And Harassed'
On January 31, the United States singled out Lisani's case in a call on Iran to respect human rights and to embrace religious and ethnic tolerance.
The State Department said that Lisani had been beaten, harassed, and imprisoned following peaceful protests.
Spokesman Sean McCormack said the Iranian government had banned the Azeri language in schools, harassed ethnic Azeri activists, and unjustly jailed them, including Lisani, for advocating cultural and linguistic rights.
He said Washington was deeply concerned by the Iranian regime's continuing oppression of Iran's ethnic and religious minority groups, including Azeris, Kurds, Baha'i, ethnic Arabs, and others.
The spokesman added that the Iranian regime's repression also affected students, women, labor unions, journalists, and academics.