Dr. Zofia Kuratowska remembers the threat well. It was autumn 1982, and she had been summoned to the Interior Ministry for another interrogation about her work for political internees.

The authorities couldn't do much to her then. Her position as medical counselor on the Polish Roman Catholic primate's committee aiding political prisoners provided a kind of protective church umbrella. But she was warned by secret police officers that she would eventually suffer consequences at her job for probing the medical condition of detainees.

Getting even, Polish officials in late December closed the Warsaw hospital ward for blood disease victims that Kuratowska headed, cut her salary and reassigned the well-known physician to an outpatient clinic in a suburb of the capital.

Officially, the move is said to have nothing to do with politics. But Kuratowska, one of Poland's outstanding specialists in hematology, was told by informed friends that the transfer was retaliation by the police and Communist Party apparatus.

Archbishop Bronislaw Dabrowski, secretary of Poland's Roman Catholic episcopate, has written to the government protesting the action, which he charged was directed as much against the church as against the doctor.

Kuratowska's boss, Dr. Stanislaw Brzozowski, director of the medical center for postgraduate education, evaded repeated requests over the past month for an interview.

The case is illustrative of the quiet forms of repression being used now by Communist authorities against political opponents. Such measures have the advantage of holding down the number of political prisoners, avoiding unfavorable international attention that could disturb improving ties between Warsaw and western capitals, while still intimidating and punishing the opposition.

Often the choice confronting Poles is not between freedom and imprisonment but between keeping a good job and being forced into a poor one, between obtaining a passport to travel abroad or not, between protecting family members or exposing them to politically motivated repercussions.

Kuratowska, 53, graduated from the Warsaw Medical Academy in 1955. She won international notice 25 years ago for locating in human kidneys a substance that regulates the production of red blood cells. About that time she was named a member of the New York Academy of Sciences.

Ten years ago she was appointed to head a ward at Warsaw's Barska Street Hospital, where she proceeded to build up a clinic specializing in the treatment of acute leukemia and other blood diseases.

During the 1980-81 Solidarity period, Kuratowska chaired a local branch of physicians aligned with the independent union movement. After martial law was declared in December 1981, she refused, like many others, to sign a government loyalty oath and was recruited to work for the primate's aid committee, for which she attempted to visit several internment camps.

One report she wrote in the summer of 1982 detailed an attack by prison guards on inmates in the northern town of Kwidzyn. Several prisoners were hospitalized as a result of beatings, which authorities alleged were in response to a riot by the inmates. Shortly after the incident was publicized, Kuratowska was summoned to the Interior Ministry and given the warning that her hospital position was in jeopardy.

A first attempt to shut her ward came not long after that, in early 1983. But a petition drive that collected 6,000 signatures succeeded in postponing the closure. Her intensive care unit was disbanded in the meantime and the number of beds under her care shrunk from 90 to 30.

At the end of December, the whole ward was closed, technically for renovation, and Kuratowska was permanently reassigned. In a city where hospital beds are already in seriously short supply and expert medical attention is hard to find, the action struck many Poles as outrageous. An effort to have Kuratowska appointed to oversee a ward at another Warsaw hospital reportedly was blocked by party officials.