A fragile three-year-old girl is diagnosed with pulmonary hypertension.

Strongly advanced.

Drugs don't help, her last chance: a lung transplant.

The penultimate chance is not in any textbook, for many it is a utopian option that has been announced for years - for some scientists and doctors at the Hannover Medical School (MHH) a realistic way out: stem cell therapy.

Now, three years later, the girl leads a normal life - without a donor lung, but with stem cell therapy.

The pediatric cardiologist Georg Hansmann and the other doctors do not yet want to talk about a cure, because the little patient's illness is a particularly serious form of pulmonary hypertension, which usually runs in flares and can therefore break out again sooner or later.

Nonetheless, the girl's recovery so far is a terrific achievement in regenerative medicine, which can be read about in the journal Nature Cardiovascular Medicine.

When the parents of little Jenny (name changed by the editors) contacted the Hanover doctors in January 2019, she had already endured a ten-month ordeal.

Unusually small and delicate for her age, the little patient had not grown for about a year and weighed only twelve kilograms.

She had also lost consciousness twice in connection with seizures and suffered from repeated nosebleeds.

When her comrades of the same age were romping and playing, Jenny had to watch because she was out of breath after a short time.

In a standardized stress test in the clinic, she was only able to cover 270 meters in six minutes, she couldn't do more.

Even 400 meters is considered little for children of this age.

Lung transplantation is the only option left

The cause of the suffering of the then three-year-old was a rare genetic defect that had not previously occurred in her family, so it must have developed spontaneously.

As is known from the few comparable cases, the pulmonary arteries of those affected are extremely stiff and narrow due to severe growth disorders.

As a result, the pressure in the pulmonary vascular system increases and the right ventricle has to constantly pump against a high resistance in order to transport the blood through the respiratory organ.

If the pulmonary high pressure - known as pulmonary arterial hypertension in technical jargon - persists or increases further, which is usually the case with genetic diseases, the heart increasingly loses strength and eventually lays down its arms completely.

It reaches this stage all the sooner the earlier in life it is subjected to such great hardship.

The survival prospects of patients who, like Jenny, develop pulmonary hypertension as children are therefore particularly bleak.

In the advanced stage of the disease, only a lung transplant can prevent the circulatory pump from failing completely.

Admittedly, this option is far from ideal.

On the one hand, transplanted lungs have a limited lifetime, and on the other hand, the immune system must be constantly suppressed so that the body does not reject the foreign organ.

Getting children, and especially teenagers, to take pills consistently can be a challenge.