Erin and Kelly Land were leading miserable lives: Kelly, who is now 7, and Erin, 9, both suffered from a form of glomercular nephritis, one of the most common forms of kidney disease.

First the little boy, and then his sister, were coincidentally struck by the disease, which eventually destroyed their kidneys and forced them to depend upon dialysis, the use of an artificial kidney machine, for life.

Their diets were severely restricted, their resistances were lowered and they were constantly sick; their growth was stunted and they both faced severe physical and emotional problems.

That was until June, 1976, in Kelly's case, and last June in Erin's.

Today the youngsters go to school, play and eat like other children. And they are no longer dependent on the machine.

Instead, each child has a new kidney. Kelly's was donated by their father, C.B. Land, and Erin's by their mother, Judy Land.

The children were given their transplants by Dr. Charles Durrier, who heads a joint Georgetown University Medical Center kidney transplantation program.

Since 1975 the program has performed 23 transplants, 20 of them on children, the youngest of whom was 2 years old.

With children we see dialysis as purely a temporary matter," Currier said yesterday, explaining that children on dialysis do not grow as they should and that their "quality of life is not as good" as it is for adults on dialysis, who usually adjust better to the procedure.

"Technically, the children are a little more challenging" to transplant, said Currier, because the operation involves "putting an adult-size kidney into a small child." The program has yet to transplant a kidney into a child weighing less than about 40 pounds.

As in the case with adults, children do much better when they receive a kidney donated by a living, close relative, such as a sister, brother or parent. Currier said that, thus far, not one such transplant has failed, compared to about an 85 per cent success rate for similar transplants of adults in the program.

On the other hand, children apparently do much worse than adults when given kidneys from cadavers. Only one such pediatric transplant has succeeded, according to Currier, who said he does not know why children receiving cadaver transplants do so poorly.

He said, however, that while some of the transplants have fialed, no child in the program has died. Unlike patients who receive heart transplants, kidney patients have a machine to which they can return while awaiting another transplant.

C.B. Land, Kelly and Erin's father, said Kelly was "sick for a long time," having first shown signs of the illness in 1973. "It was either allergies or pneumonia, he has always on medication and down with something.

"He wouldn't take any of the dietary supplements," he needed while on dialysis, Land continued. "He wouldn't take it. It was like force-feeding an animal . . . Some children adjust and some don't. We've known about Kelly's condition since 1973 and Erin's since 1975 . . . I don't know how you cope."

The two children look normal now, except for the tell-tale puffiness about the face caused by the antirejection medication both take! Both are receiving psychiatric therapy for "all the problems that came about as a result of the illness," Land said.

"We were so miserable, seeing them suffer so much, trying to control their diets," said Judy Land. "There was just very little they could eat. They were only allowed 10 ounces of fluid a day and with what they had to take 27 pills a day.

"Erin went through a very serious depression on dialysis," said her mother, "but she's regained a lot of her personality."

Kelly, she said, has also had problems, "as a result of going through what he did at such an early age."

Both Judy and C. B. Land had the same fears as "anyone undergoing surgery, a bit of apprehension," but both parents, said Judy Land, did not hestitate to give kidneys to their children.

"We kid a lot about the kidneys," said Judy Land, "about whose kidney was the best."