WHAT IS ATYPICAL HUS?

  ATYPICAL HUS
Atypical HUS (Hemolytic Uremic Syndrome) is not caused by an external agent (such as a bacteria, virus etc). Instead, some sort of internal chain of events sets the disease off, and the syndrome becomes active. The syndrome is not well understood. In many cases, it has been identified as a genetic problem due to an irregularity in several suspect genes. In these cases, there appears to be strong inherited tendencies. In other cases, the disease appears out of nowhere. This is called an "idiopathic" cause. Idiopathic causes are believed to originate from a mutated gene. There are a variety of other Atypical causes, such as HIV and Pregnancy induced HUS. In either case, Atypical HUS patients have many of the same symptoms as "Typical HUS Patients, but there are significant differences as well, as we see below:

DIFFERNCES BETWEEN "ATYPICAL HUS" and "REGULAR" HUS
  ATYPICAL HUS HUS
Caused by a Bacteria or Virus

No

Yes
Initial Symptoms are severe

No

Yes
Accompanied by Severe Diarhea

No

Yes
Dialysis often needed

Yes

Yes
Blood Pressure Regulation Problems

Yes

Yes
Temporary Kidney Failure is Common

Yes

Yes
Permanent Kidney Failure is Common

Yes

No
Disease is often Recurring

Yes

No
Complications throughout life may occur

Yes

No
May be caused by a Gene Problem

Yes

No

As we can see, the Atypical form is subject to longer lingering effects, and is much more likely to become a chronic problem. Recurring episodes are much more common with the Atypical form of the disease. Atypical Cases frequently start out with flu-like symptoms that do not go away. Eventually, the lethargic behavior results in loss of appetite. A simple blood test will show shattered red blood cells, and low platelet counts, a definite sign of Atypical HUS.

FREQUENCY

Typical or regular HUS is rare, but Atypical HUS is even more rare. The number of cases in the US are believed to be around 300, and it occurs worldwide, but the frequency is unknown. Since Atypical HUS is not a communicable disease, reporting on it is not mandatory, but optional.

THE ADULT VERSION

Atypical HUS is most common with young children. The reason for that is unknown, but some believe that the genetic problem is present, but does not become activated until a virus such as the flu, or a bacterial infection occurs. Adults can get a disease with many of the same symptoms. Sometimes, the adults are diagnosed with Atypical HUS. But more often, the adult version involves different symptoms. So quite often, the adult version is called TTP, or thrombotic thrombocytopenic purpura. TTP has a lot of similarities to Atypical HUS, but the symptoms do not show up as kidney failure. Instead, the disease exhibits a lot of Neurological signs. See the links page for some additional sites related to TTP.

TYPICAL HUS

The most common type of HUS (Hemolytic Uremic Syndrome) is called "Typical HUS", or simply HUS
--Rare condition occurring mostly in children
--Also called infectious HUS
--Often accompanied by severe vomiting and diarrhea
--Most common source is E-Coli bacteria (from improperly cooked meat)
--Other Gastronomical bacteria and viruses could also be a cause
If the child survives the initial stages of the disease, the long term prognosis is good.
--Disease causes destruction of red blood cells, damage to the lining of blood vessel walls, and in severe cases, kidney failure
--Recovery time varies from several days to months
--Damaged red blood cells may clog the tiny blood vessels in the kidneys, making kidneys work hard, and dialysis may be necessary

ABOUT ATYPICAL HUS

There is no cure for HUS. In fact, there is no standard treatment, as each case is different.
Children with typical HUS are in a life threatening situation, but if they survive the intial stages of the disease, they usually respond good to the supportive treatment.
Children with Atypical HUS are much more likely to develop complications. These complications may be:
--Recurrance
--Kidney failure
--Seizures/Neurological problems
--No response to supportive treatments
--Return of HUS even after s kidney transplant occurs
--Severe Hypertension (high blood pressure)

Back to top