As Bence Jones proteinuria is the presence of light chain nephrotoxic Para proteins known as Bence Jones proteins, referred to in the urine. These functionless light chain proteins are fragments of antibodies that are produced by B lymphocytes. Their increased occurrence often indicates a malignant increase in B-lymphocytes.
What is Bence Jones Proteinuria?
In Bence Jones proteinuria, so-called Bence Jones proteins are excreted in the urine. The Bence Jones proteins are light chain proteins that are derived from antibodies. They are formed especially in cancers of the blood-forming system. Their presence in the urine can therefore indicate a malignant proliferation of lymphocytes.
But even if there is a benign increase in lymphocytes during an infection, more Bence Jones proteins can be formed. The Bence Jones proteins were first described in 1848 by the English doctor Henry Bence Jones. He also recognized a link between the appearance of these proteins and multiple myeloma.
The Bence Jones proteinuria is even considered to be clearly indicative of this. Bence Jones proteinuria is not an independent disease, but a symptom of lymphoma, multiple myeloma, Waldenström’s disease and temporary increased formation of lymphocytes.
However, the Bence Jones proteins themselves are toxic to the kidneys and can lead to kidney failure if they are chronically exposed. Renal toxicity results from the property of the protein to form deposits in the glomerular capillaries or the distal renal tubules. This leads to long-term kidney damage and kidney failure.
Causes
Possible causes of Bence Jones proteinuria are multiple myelomas, Waldenström’s disease, various lymphomas, temporary increased formation of immunoglobulins in infections, or monoclonal gammopathy of unclear significance (MGUS). Multiple myeloma is a cancer within the blood-producing system.
This leads to an increased formation of monoclonal B lymphocytes in the bone marrow. As a result, monoclonal antibodies and light chain proteins (parts of immunoglobulins) are formed. The light chain proteins or Bence Jones proteins have no function and are excreted in the urine. Multiple myeloma, on the other hand, is not a single disease.
It always starts from a single degenerate cell which, as a result of its uninhibited reproduction, displaces the other cells of the blood-forming system. Other lymphomas and Waldenström’s disease can also lead to the formation of Bence Jones proteins. These diseases are also a malignant proliferation of lymphocytes. Waldenström’s disease is similar to multiple myeloma. However, the course of the disease is much slower here.
Bence Jones proteinuria can also occur with monoclonal gammopathy of unclear significance (MGUS). In a few cases, MGUS is a precursor to the cancer diseases mentioned above. The term gammopathy refers to the gamma fraction in the detection of the Bence Jones proteins in the context of serum protein electrophoresis. Temporary gammopathy can also occur as a result of increased immune reactions in infectious diseases.
Symptoms, ailments & signs
The main symptom of Bence Jones proteinuria is the increased occurrence of light chain proteins in the urine. The other symptoms are determined on the one hand by the underlying disease and on the other hand by the consequential damage to the kidneys caused by the influence of the light chains. In the case of a simple monoclonal gammopathy of unclear significance, it is also possible that no further symptoms appear.
In multiple myeloma, bone pain, breakdown of bone substance, shoulder pain, back pain, fatigue, loss of performance, susceptibility to infections as well as fever, weight loss and night sweats occur. Similar symptoms are also observed with the other lymphomas and with Waldenström’s disease.
With Waldenström’s disease, there are often no symptoms at all for years. The damage to the kidneys in advanced stages of the disease can, if left untreated, lead to urine poisoning with nausea, vomiting, a tendency to bleed and impaired consciousness up to a coma.
Diagnosis & course
Bence Jones proteinuria can be detected using laboratory methods such as SDS polyacrylamide gel gradient electrophoresis (SDS-PAGE) or immunoelectrophoresis. With the help of these methods, only a qualitative determination of the light chain proteins is possible. The Bence Jones proteins can be quantitatively determined by nephelometry. In nephelometry, the concentration of the precipitated particles is measured by passing light through a cuvette with a cloudy liquid.
Complications
Bence Jones proteinuria occurs primarily in the context of multiple myeloma or plasmacytoma. With this tumor disease, the bone is severely emaciated, so that it can break and break more easily. The vertebral bodies are particularly affected, and important nerve tracts can be endangered as a result.
As a result of the disease, the body no longer produces enough important antibodies that are responsible for the defense against pathogens. This makes the body more susceptible to infections, which can even be fatal. Since the tumor also grows in the area of the bone marrow, this is displaced and there may be a shortage of important blood cells such as the platelets (thrombocytes), which are responsible for clotting.
This increases the bleeding time for those affected. The therapy can also cause serious complications, since the chemotherapeutic agents used cannot differentiate between cancerous and healthy cells and thus damage both. As a result of an extremely high excretion of Bence Jones proteins, kidney failure (renal insufficiency) can occur.
The kidneys can no longer carry out their activities and substances to be excreted by the kidney remain in high concentrations in the body, so that blood poisoning can occur (uremia). This can lead to a coma and ultimately to death of the patient. Anemia as a result of kidney failure is also quite conceivable, as there are no hormones produced by the kidney for blood formation.
When should you go to the doctor?
In most cases, the symptoms and symptoms of Bence Jones proteinuria are not particularly characteristic and therefore do not directly indicate the disease. For this reason, a doctor should be consulted if the symptoms of this disease persist over a long period of time. A doctor should be consulted, especially in the case of persistent bone pain or back pain.
Fatigue and poor performance can also indicate Bence Jones proteinuria and should therefore be examined by a doctor. Most people continue to have a fever and sudden weight loss from the disease. An increased susceptibility to various infections and inflammations must also be examined by a doctor in order to possibly diagnose the disease.
As a rule, the general practitioner can be seen in the case of Bence Jones proteinuria. This can determine the disease. Further treatment will be carried out by other specialists. The earlier the disease is diagnosed, the higher the life expectancy of the person affected.
Treatment & Therapy
Treatment for Bence Jones proteinuria depends primarily on the underlying condition. In some cases, no therapy is necessary at all. This applies, among other things, to monoclonal gammopathy of unclear significance (MGUS). MGUS is also not defined as a disease. Often the concentration of the light chain proteins formed is so low that no further impairments result.
However, if MGUS is present, regular medical check-ups should take place. Multiple myelomas or other lymphomas can occur in around one to one and a half percent of all monoclonal gammopathies of unclear significance. Multiple myeloma is treated palliatively by chemotherapy with various chemotherapeutic agents. Curative therapy is possible with the help of bone marrow transplantation.
However, not all forms of this disease are suitable for stem cell transplantation from the bone marrow. The breakdown of bones is slowed down with the administration of bisphosphonates. Infections should be treated immediately with antibiotics and, if necessary, with immunoglobulins.
Regular dialysis is necessary for severe kidney damage. Waldenström’s disease is treated with medication. It is usually a palliative treatment to delay the course of the disease. Drug therapy often makes it possible to extend survival time even by decades.
Outlook & forecast
Bence Jones proteinuria has an unfavorable prognosis. In many cases, treatment is no longer necessary due to the patient’s already severely weakened immune system. The disease develops as a consequence of an existing tumor disease. The treatment of the cancer also has an impact on the fight against Bence Jones proteinuria.
The therapy is nevertheless very complex for the organism and associated with numerous complications. Often the patient’s remaining natural resources are insufficient to initiate treatment. Nevertheless, medical care is currently the only way to improve health.
There is no recovery with alternative methods or the body’s self-healing powers. The patient is threatened with death. When the disease occurs, the organism already has a very low defensive function. Due to the cancer present, the antibodies are no longer independently produced to a sufficient extent.
In most cases, a bone marrow transplant must be performed for the underlying disease and Bence Jones proteinuria to be cured. If this treatment is successful, the patient’s chances of recovery increase. Still, the death rate remains very high. In addition, the tumor may return or further metastases may have formed in the body. In many cases permanent and irreparable kidney damage occurs.
Prevention
No specific recommendations can be made for the prevention of Bence Jones proteinuria. Environmental influences such as ionizing radiation, contact with herbicides or the corresponding genetic predisposition are considered risk factors for multiple myeloma. In general, however, a healthy lifestyle can lower the risk of cancer. If MGUS is present, regular medical checks should be carried out.
You can do that yourself
Bence Jones proteinuria does not necessarily have to be treated. Therapy focuses on alleviating the underlying monoclonal gammopathy. However, accompanying measures are useful. The patient should first take steps to encourage kidney function. This includes an abundant intake of fluids as well as a healthy and balanced diet. Alcohol, caffeine and other substances that put a strain on the kidneys should be avoided.
If the course is severe, curative therapy is indicated. In consultation with the doctor, it can be useful, for example, to initiate palliative therapy. This includes, for example, protection. In the later stages of the causal disease, a stay in a specialist clinic or in a nursing home may be necessary. Since Bence Jones proteinuria can often be traced back to radiation therapy or chemotherapy, a recurrence or even an intensification of the existing symptoms through renewed treatment cannot be completely ruled out.
However, the doctor may consider alternative treatment options. In some cases, radiation therapy can be replaced by surgical removal of a tumor. Patients should contact their doctor and discuss further steps with them.
