Hodgkin's Disease

Hodgkin's Disease refers to a condition that was first described by British physician Thomas Hodgkin. Hodgkin's disease or Hodgkin's lymphoma is a malignant growth of lymph cells. This uncommon form of cancer of the lymph system is characterized by abnormal growth of cells in the lymph system thereby spreading beyond it. It progressively compromises the body's immune system. While Hodgkin's disease can occur to a person at any time of his life, it is noticed in early adulthood or late adulthood. Usually, Hodgkin's disease begins in the lymph nodes and may spread to other parts of the body. The difference between Hodgkin's disease and non-Hodgkin's lymphoma is that tumors in Hodgkin's syndrome contain large cells called Reed-Sternberg cells.

Patients suffering from Hodgkin's disease notice painless swelling in the lymph nodes of the neck, armpit or groin. There may be fever and fatigue. The patient loses weight and feels drained of energy. Unexplained itching and lower back pain may also be noticed.

Most often diagnosis of Hodgkin's lymphomas is made during physical check-ups. A biopsy is done to test for the presence of Reed-Sternberg cells that are characteristic to Hodgkin's lymphomas. Blood test will reveal abnormal blood cell count and ESR. Bone marrow aspiration is done to aid diagnosis and treatment. Cellular activity can be traced with Positron Emission Tomography (PET) scan. Treatment for Hodgkin's disease depends on the stage that the disease is in. This determines the extent and region of lymph nodes that have been affected.

Radiation therapy is resorted to when a limited area is affected by Hodgkin's disease. Here high-energy rays are used to kill cancer cells and stop their proliferation. Often it is used in combination with chemotherapy. Chemotherapy may involve a combination of drugs that work together.

Immunochemistry

The process of localizing proteins in cells of a tissue section using the principle of antigens in tissue binding to their respective antibodies is known as Immunohistochemistry (IHC). This technique is widely used for the diagnosis of cancer. The antibodies are tagged with color-producing dyes to make them easily visible. Horseradish peroxidase and phosphatase are the two commonly used color-producing tags. Different fluorophores like FITC are also used to tag the antibodies as an alternate method. This method is widely used in confocal laser scanning microscopy to visualize two interacting protein molecules. Adinocarcinomas, Hodgkin's disease, yolk sac tumors and hepatocellular carcinoma, Gastrointestinal Stromal Tumors (GIST) and prostate cancer are diagnosed by conducting immunohistochemistry using various antigens like Carcinoembryonic antigen, CD 15 & CD30 or Alpha fetoprotein or CD117 or prostate specific antigen accordingly. Direct and indirect methods are the two methods used for the immunohistochemical staining of antigens.

In the direct method, one labelled antibody is used for staining. The antibody directly binds to the antigen which is being stained. Involving only one labeled antibody (FITC conjugated antiserum), this direct method is also known as one-step staining method. Though this method is quick since it uses only one antibody, it is rarely used after the indirect method was introduced.

In the indirect method of immuno-histochemical staining, one antibody is used against the antigen which is being examined and a second labelled antibody is used against the first. The unlabelled primary antibody or the first layer reacts with tissue antigen and the second layer or the labelled secondary antibody reacts with the primary antibody. This indirect method is considered more sensitive, since there is good signal amplification noticed through many secondary antibody reactions with various antigenic sites on the primary antibody.

Guillain Barre Syndrome

Guillain Barre syndrome or GBS (also known as infectious polyneuritis) is a rare disease that affects the peripheral nervous system. This condition arises when the body's immune system attacks the peripheral nerves after an infection or an immunization. Guillain-Barre syndrome affects the myelin sheath that covers nerve cells. The loss of myelin is called as demyelination. It causes progressive muscle weakness usually starting in the lower extremities and often ascending to the muscles involved in respiration and usually reversible paralysis which develops over days or up to four weeks and lasts several weeks to several months.

Guillain-Barre syndrome can be life-threatening. Typically GBS follows an infection such as sore throat, Hodgkin's disease or other bacterial diseases. Sometimes surgery can trigger GBS. A severe attack of Guillain-Barre syndrome can leave a patient totally paralyzed. The patient has difficulty in breathing and sharp fluctuations in blood pressure and pulse rate.

Symptoms may start with muscle weakness in the legs first, then it progresses to the arms and face. Paresthesia (abnormal skin sensation like tingling) often occurs at the same time. Again the disorder doesn't restrict its action to one side alone. This affects both sides of the body and may involve paralysis of the muscles that control breathing.

Symptoms of Guillain-Barre syndrome include severe numbness and weakness in the limbs. It can result in loss of feeling and movement and temporary paralysis. There may be bouts of headache and vomiting. Symptoms such as tingling in the limbs and muscle weakness are characteristic of GBS.When Myelin (sheath that wraps around nerves), which is responsible for speed and efficiency of impulses traveling through those nerves, suffers damage, nerve communication is disrupted. The most common preceding infections are cytomegalovirus, herpes, Epstein-Barr virus and viral hepatitis. A gastrointestinal infection with the bacteria Campylobacter jejuni is also common. Patients with infections that impair body defense system like lymphoma, systemic lupus erythematosus or AIDS, have a higher than normal risk of GBS.

Diagnosis Early diagnosis is vital to the treatment of Guillain-Barre syndrome. Diagnosis of GBS is primarily to look for a particular cluster of symptoms which start with progressively worse muscle weakness and then paralysis. A spinal tap is another diagnostic mechanism that helps to determine the pressure of the cerebrospinal fluid (CSF) that bathes the brain and spinal canal. This fluid is obtained by a lumbar puncture, which upon examination will reveal a greater than normal quantity of protein but with normal numbers of white blood cells and a normal amount of sugar. A nerve conduction velocity (NCV) test can aid the doctor in diagnosis of Guillain-Barre syndrome. Electromyography helps in identifying the extent of damage to the neurological system. Electrodiagnostic studies may show slowing or a block of conduction in nerve endings in parts of the body other than the brain.

Treatment If diagnosed within the early weeks, patients suffering from Guillain-Barre syndrome can recover in good time. Although there is no direct treatment for Guillain-Barre syndrome, palliative care, and symptom management is usually attempted. Careful attention must also be paid to the amount of fluid intake. Blood pressure, heart rate and heart rhythm also must be monitored. Plasmapheresis and high-dose immunoglobulin therapy are used to treat Guillain-Barre syndrome. Plasmapheresis consists of withdrawing the patient’s blood, passing it through an instrument that separates the different types of blood cells and returning all the cellular components along with either donor plasma or a manufactured replacement solution. This process is resorted to rid the blood of the substances that are attacking the myelin. Severe cases of GBS need hospitalization. Critical body functions need to be monitored during the recovery of the nervous system.

Prognosis Usually about 85 % of cases of GBS recover with little complications. But some 30 % adult cases and a larger percentage of children never regain their functions completely. Elderly patients and patients who had their worst symptoms within the first 7 days have a higher risk of dying due to complications.