(Medicare National Coverage Determinations Manual)

3. The HIV antigen tests currently have no defined diagnostic usage.   4. Direct viral RNA detection may be performed in those situations where serologic testing does not establish a diagnosis but strong clinical suspicion persists (for exam ple, acute retroviral syndrome, nonspecific serologic evidence of HIV, or perinatal HIV infection).   5. If initial serologic tests confirm an HIV infection, repeat testing is not indicated.   6. If initial serologic tests are HIV EIA negative and there is n o indication for confirmation of infection by viral RNA detection, the interval prior to retesting is 3- 6 months.  7. Testing for evidence of HIV infection using serologic methods may be medically appropriate in situations where there is a risk of exposure  to HIV.   8. The CPT Editorial Panel has issued a number of codes for infectious agent detection by direct antigen or nucleic acid probe techniques that have not yet been developed or are only being used on an investigational basis.  Laboratory providers a re advised to remain current on FDA -approved status for these tests.   190.15 - Blood Counts  (Rev. 17, Issued: 07- 02-04) (Effective/Implementation: Not Applicable) PM AB -02-110  Blood counts are used to evaluate and diagnose diseases relating to abnormalities of the blood or bone marrow.  These include primary disorders such as anemia, leukemia, polycythemia, thrombocytosis and thrombocytopenia.  Many other conditions secondarily affect the blood or bone marrow, including reaction to inflammation and infections, coagulopathies, neoplasms and exposure to toxic substances.  Many treatments and therapies affect the blood or bone marrow, and blood counts may be used to monitor treatmen t effects.   The complete blood count (CBC) includes a hemogram and differential white blood count (WBC).  The hemogram includes enumeration of red blood cells, white blood cells, and platelets, as well as the determination of hemoglobin, hematocrit, and indices.   The symptoms of hematological disorders are often nonspecific, and are commonly encountered in patients who may or may not prove to have a disorder of the blood or bone marrow.  Furthermore, many medical conditions that are not primarily due to abnormalities of blood or bone marrow may have hematological manifestations that result from the disease or its treatment.  As a result, the CBC is one of the most commonly indicated laboratory tests.   Inpatients with possible hematological abnormalities, it may be necessary to determine the hemoglobin and hematocrit, to calculate the red cell indices, and to measure the concentration of white blood cells and platelets.  These measurements are usually performed on a multichannel analyzer that measures all of t he parameters on every sample.  Therefore, laboratory assessments routinely include these measurements.  Indications   Indications for a CBC or hemogram include red cell, platelet, and white cell disorders.  Examples of these indications are enumerated indi vidually below.  1. Indications for a CBC generally include the evaluation of bone marrow dysfunction as a result of neoplasms, therapeutic agents, exposure to toxic substances, or pregnancy.  The CBC is also useful in assessing peripheral destruction of blood cells, suspected bone marrow failure or bone marrow infiltrate, suspected myeloproliferative, myelodysplastic, or lymphoproliferative processes, and immune disorders.   2. Indications for hemogram or CBC related to red cell (RBC) parameters of the hemogram i nclude signs, symptoms, test results, illness, or disease that can be associated with anemia or other red blood cell disorder (e.g., pallor, weakness, fatigue, weight loss, bleeding, acute injury associated with blood loss or suspected blood loss, abnormal  menstrual bleeding, hematuria, hematemesis, hematochezia, positive fecal occult blood test, malnutrition, vitamin deficiency, malabsorption, neuropathy, known malignancy, presence of acute or chronic disease that may have associated anemia, coagulation or  hemostatic disorders, postural dizziness, syncope, abdominal pain, change in bowel habits, chronic marrow hypoplasia or decreased RBC production, tachycardia, systolic heart murmur, congestive heart failure dyspnea, angina, nailbed deformities, growth retardation, jaundice, hepatomegaly, splenomegaly, lmphadenopathy, ulcers on the lower extremities).   3. Indications for hemogram or CBC related to red cell (RBC) parameters of the hemogram include signs, symptoms test results illness, or disease that can be ass ociated with polycythemia (for example, fever, chills, ruddy skin, conjunctival redness, cough, wheezing, cyanosis, clubbing of the fingers, orthopnea, heart murmur, headache, vague cognitive changes including memory changes, sleep apnea, weakness, pruritus, dizziness, excessive sweating, visual symptoms, weight loss, massive obesity, gastrointestinal bleeding, paresthesias, dyspnea, joint symptoms, epigastric distress, pain and erythema of the fingers or toes, venous or arterial thrombosis, thromboembolism , myocardial infarction, stroke, transient ischemic attacks, congenital heart disease, chronic obstructive pulmonary disease, increased erythropoietin production associated with neoplastic, renal or hepatic disorders, androgen or diuretic use, splenomegaly, hepatomegaly, diastolic hypertension.)   4. Specific indication for CBC with differential count related to the WBC include signs, symptoms, test results, illness, or disease associated with leukemia, infections or inflammatory processes, suspected bone marrow failure or bone marrow infiltrate, suspe cted myeloproliferative, myelodysplastic or lymphoproliferative disorder, use of drugs that may cause leukopenia, and immune disorders (e.g., fever, chills, sweats, shock, fatigue, malaise, tachycardia, tachypnea, heart murmur, seizures, alterations of consciousness, meningismus, pain such as headache, abdominal pain, arthralgia, odynophagia, or dysuria, redness or swelling of skin, soft tissue bone, or joint, ulcers or the skin or mucous membranes, gangrene, mucous membrane discharge, bleeding, thrombosis, respiratory failure, pulmonary infiltrate, jaundice, diarrhea, vomiting, hepatomegaly, splenomegaly, lymphadenopathy, opportunistic infection such as oral candidiasis.)   5. Specific indication for CBC related to the platelet count include signs, symptoms, te st results, illness, or disease associated with increased or decreased platelet production and destruction, or platelet dysfunction (e.g., gastrointestinal bleeding, genitourinary tract bleeding, bilateral epistaxis, thrombosis, ecchymosis, purpura, jaundi ce, petechiae, fever, heparin therapy, suspected DIC, shock, pre -eclampsia, neonate with maternal ITP, massive transfusions, recent platelet transfusion, cardiopulmonary bypass, hemolytic uremic syndrome, renal diseases, lymphadenopathy, hepatomegaly, sple nomegaly, hypersplenism, neurologic abnormalities, viral or other infection, myeloproliferative, myelodysplastic, or lymphoproliferative disorder, thrombosis, exposure to toxic agents, excessive alcohol ingestion, autoimmune disorders (SLE, RA and other).   6. Indications for hemogram or CBC related to red cell (RBC) parameters of the hemogram include, in addition to those already listed, thalassemia, suspected hemoglobinopathy, lead poisoning, arsenic poisoning, and spherocytosis.]   7. Specific indications for CB C related to differential count related to the WBC include, in addition to those already listed, storage diseases; mucopolysaccharidoses, and use of drugs that case leukocytosis such as G -CSF or CM -CSF.   8. Specific indications for CBC related to platelet cou nt include, in addition to those already listed, May -Hegglin syndrome and Wiskott -Aldrich syndrome.   Limitations   1. Testing of patients who are asymptomatic, or who do not have a condition that could be expected to result in a hematological abnormality, is s creening and is not a covered service.   2. In some circumstances it may be appropriate to perform only a hemoglobin or hematocrit to assess the oxygen carrying capacity of the blood.  When the ordering provider requests only hemoglobin or hematocrit, the rema ining components of the CBC are not covered.   3. When a blood count is performed for an end- stage renal disease (ESRD) patient, and is billed outside the ESRD rate, documentation of the medical necessity for the blood count must be submitted with the claim.   4. In some patients presenting with certain signs, symptoms, or diseases, a single CBC may be appropriate.  Repeat testing may not be indicated unless abnormal results are found, or unless there is a change in clinical condition.  If repeat testing is  performed, a more descriptive diagnosis code (e.g., anemia) should be reported to support medical necessity.  However, repeat testing may be indicated where results are normal in patients with conditions where there is a continued risk for the development  of hematologic abnormality.  190.16 - Partial Thromboplastin Time (PTT)  (Rev. 17, Issued: 07- 02-04) (Effective/Implementation: Not Applicable) PM AB -02-110  Basic plasma coagulation function is readily assessed with a few simple laboratory tests:  The PTT, prothrombin time (PT), thrombin time (TT), or a quantitative fibrinogen determination.  The PTT test is an in vitro laboratory test used to assess the intrinsic coagulation pathway and monitor heparin therapy.   Indications   1. The PTT is most commonly used to quantitate the effect of therapeutic unfractionated heparin and to regulate its dosing.  Except during transitions between heparin and warfarin therapy, in general both the PTT and PT are not necessary together to assess the effect of anti coagulation therapy.  PT and PTT must be justified separately.   2. A PTT may be used to assess patients with signs or symptoms of hemorrhage or thrombosis.  For example:  Abnormal bleeding, hemorrhage or hematoma petechiae or other signs of thrombocytopenia t hat could be dues to disseminated intravascular coagulation; swollen extremity with or without prior trauma.   3. A PTT may be useful in evaluating patients who have a history of a condition known to be associated with the risk of hemorrhage or thrombosis that  is related to the intrinsic coagulation pathway.  Such abnormalities may be genetic or acquired.  For example: dysfibrinogenemia; afibrinogenemia (complete); acute or chronic liver dysfunction or failure, including Wilsons disease; hemophilia; liver dise ase and failure; infectious processes; bleeding disorders; disseminated intravascular coagulation; lupus erythematosus or other conditions associated with circulating inhibitors e.g., factor VIII inhibitor, lupus -like anticoagulant; sepsis; vonWillebrands  disease; arterial and venous thrombosis, including the evaluation of hypercoagulable states; clinical conditions associated with nephrosis or renal failure; other acquired and congenital coagulopathies as well as thrombotic states.   4. A PTT may be used to a ssess the risk of thrombosis or hemorrhage in patients who are going to have a medical intervention known to be associated with increased risk of bleeding or thrombosis.  An example is as follows: evaluation prior to invasive procedures or operations of pa tients with personal or family history of bleeding or who are on heparin therapy.   Limitations   1. The PTT is not useful in monitoring the effects of warfarin on a patients coagulation routinely.  However, a PTT may be ordered on a patient being treated with warfarin as heparin therapy is being discontinued.  A PTT may also be indicated when the PT is markedly prolonged due to warfarin toxicity.  2. The need to repeat this test is determined by changes in the underlying medical condition and/or dosing of heparin.   3. Testing prior to any medical intervention associated with a risk of bleeding and thrombosis (other than thrombolytic therapy) will generally be considered medically necessary only where there are signs or symptoms of a bleeding or thrombotic  abnormality or a personal history of bleeding, thrombosis or a condition associated with a coagulopathy.  Hospital/clinical -specific policies, protocols, etc., in and of themselves, cannot alone justify coverage.   190.17 - Prothrombin Time (PT)  (Rev. 17, Issued: 07 -02-04) (Effective/Implementation: Not Applicable) PM AB -02-110